a. Sandalwood b. Mistletoe c. Orobanche d. Ganoderma correct option –(a ) explanation – sandalwood is observed as partial root parasite because it fulfil its nutritional demands from other plants ....
18. Lichens are an association of:
a. bacteria and fungus b. alga and bacterium c. fungus and alga d. fungus and virus correct option –( c ) explanation – lichens are symbiotic association between fungi and photosynthetic partners...
Identify the inappropriate statement.
a. In asexual reproduction, the offspring produced are morphologically and genetically identical to the parent. b. In asexual reproduction, a single parent produces offspring with or without the...
There are various types of reproduction. The type of reproduction adopted by an organism depends on:
a. The habit and habitat of the organism b. Organism’s physiology, and genetic makeup c. Morphology and anatomy of the organism d. Physiology of the organism Solution: Option (b) is the...
17. Amensalism is an association between two species where:
a. one species is harmed and other is benefitted b. one species is harmed and other is unaffected c. one species is benefitted and other is unaffected d. both the species are harmed. correct option...
16. In 2005, for each of the 14 million people present in a country, 0.028 were born and 0.008 died during the year. Using the exponential equation, the number of people present in 2015 is predicted as:
a. 25 million b. 17 million c. 20 million d. 18 million correct option –( b ) explanation – we apply the exponential formula for population growth and will find it that 17 million people will be...
15. A protozoan reproduces by binary fission. What will be the number of protozoans in its population after six generations?
a. 128 b. 24 c. 64 d. 32 correct option –( c ) explanation – by binary fission the protozoan divides into two . I fit goes like this then after 6 years the population of protozoan will be 64 ....
Natural death does not take place in single-celled organisms like Amoeba and bacteria because:
a. They are not able to reproduce sexually b. Binary fission does not occur. c. They are macroscopic d. The parental body is distributed among the offspring Solution: Option (d) is the...
14. Which of the following would necessarily decrease the density of a population in a given habitat?
a. Natality > mortality b. Immigration > emigration c. Mortality and emigration d. Natality and immigration correct option –( c ) explanation – mortality means death and emigration ( moving...
Offspring formed by sexual reproduction exhibit more variation than those formed by Asexual reproduction because:
a. Sexual reproduction is a tedious process b. A greater amount of DNA is involved in sexual reproduction. c. Genetic material comes from parents of two different subspecies d. Gametes of parents...
13. What parameters are used for tiger census in our country’s national park’s and sanctuaries ?
a. Pugmarks only b. Pugmarks and faecal pellets c. Faecal pellets only d. Actual headcounts correct option –( b ) explanation – tiger census is carried out in our country every year . It is used to...
Choose the appropriate statement:
a. Dioecious (hermaphrodite) organisms are not seen in animals b. Dioecious organisms are seen only in animals c. Dioecious organisms are not seen only in invertebrates d.Dioecious organisms are...
12. A population has more young individuals compared to older individuals. What would be the status of the population after some years?
a. It will decline b. It will stabilise c. It will increase d. It will first decline and then stabilize correct option –( c ) explanation – if there are more young individuals as compared to older...
Which of the following statements, support the view that an elaborate sexual reproductive process appeared much later in the organic evolution.
i. Lower groups of organisms have a simpler body design ii. Asexual reproduction is common in higher groups iii. Asexual reproduction is mainly found in lower groups of organisms iv. The high...
Which of the following situations correctly describe the similarity between an angiosperm egg and a human egg?
i. Eggs of both are formed several times in their lifespan. ii. Both the angiosperm egg and human egg are immobile. iii. Both the angiosperm egg and gymnosperm egg are motile. iv. Syngamy in both...
The appearance of vegetative propagules from the nodes of plants such as and sugarcane is mainly because:
a. Nodes are longer than internodes b. Nodes do not have meristematic cells c. Nodes have an elongation zone. d. Nodes have meristematic cells. Solution: Option (d) is the answer.
11. What would be the per cent growth or birth rate per individual per hour
for the same population mentioned in the previous question (Question 10)? a. 100 b. 200 c. 50 d. 150 correct option –( b ) explanation – initial number of paramecium= 50 number of paramecium after...
The statements given below describe certain features that are observed in the pistil of flowers.
i. A pistil may not produce more than one seed ii. Each stamen may have more than one ovule iii. Each carpel do not have more than one ovule iv. The pistil may or may not produce more than one seed....
9. What will happen to a well-growing herbaceous plant in the forest if it is
transplanted outside the forest in a park? a. It will grow normally b. It will grow well because it is planted in the same locality c. It may not survive because of a change in its micro-climate d....
Given below are a few statements in the context of external fertilization. Choose the correct assertions relevant to it.
i. Offspring formed as a result of external fertilization have a better chance of survival than those formed inside an organism ii. Only female gametes are released into the medium iii. Water is the...
8. Which of the following forest plants controls the light conditions at the ground ?
a. Lianas and climbers b. Shrubs c. Tall trees d. Herbs correct option – ( c ) explanation – the canopy over the tall trees is formed in the form of foliage over the forest . They are very dense ,...
A multicellular, filamentous alga exhibits a type of sexual life cycle in which the meiotic division occurs after the formation of the zygote. The adult filament of this alga has
a. haploid gametangia and haploid vegetative cells b. diploid sporangia cells and diploid gametangia c. diploid vegetative cells and haploid sporangia d.haploid vegetative cells and diploid...
7. Formation of tropical forests needs mean annual temperature and mean annual precipitation as:
a. 18 – 25°C and 150 – 400 cm b. 5 – 15°C and 50 – 100 cm c. 30 – 50°C and 100 – 150 cm d. 5 – 15°C and 100 – 200 cm correct option – ( a ) explanation – biotic and abiotic factors compose the...
The male gametes of the rice plants have 42 chromosomes in their nucleus.
The chromosome number in the female gamete, zygote and the cells ofthe seedling will be, respectively, a. 42,84, 42 b. 84, 42, 42 c. 42, 84, 84 d. 42,42, 21. Solution: Option (c) is the...
6. Salt concentration (Salinity) of the sea measured in parts per
thousand is: a. 10 – 15 b. 30 – 70 c. 0 – 5 d. 30 – 35 correct option – ( d ) explanation – the salt concentration of the is 3.5% . which means it is about 30 – 35 ppm ( parts per thousand ) . This...
A few statements with respect to non-somatic cell fusion are given below:
i. Sexual reproduction does not always require two individuals. ii.. External fertilization is a rule during sexual reproduction iii. Meiosis occurs during sexual reproduction. iv. Sexual...
5. According to Allen’s Rule, the mammals from colder climates have:
a. shorter ears and longer limbs b. longer ears and shorter limbs c. longer ears and longer limbs d. shorter ears and shorter limbs correct option –( d )explanation – Allen’s rule is that in a warm...
9. Replication was allowed to take place in the presence of radioactive deoxynucleotides precursors in E. coli that was a mutant for DNA ligase. Newly synthesised radioactive DNA was purified and strands were separated by denaturation. These were centrifuged using density gradient centrifugation. Which of the following would be a correct result?
Solution: Option (d) is the correct result.
4. The ecological niche is:
a. the surface area of the ocean b. an ecologically adapted zone c. the physical position and functional role of a species within the community d. formed of all plants and animals living at the...
8. List the various markers that are used in DNA fingerprinting.
Solution: Restriction Fragment Length Polymorphisms (RFLPs), Random Amplified Polymorphic DNAs (RAPDs), Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs), also known as...
7. Give an account of the methods used in sequencing the human genome.
Solution: DNA sequencing is the method used to detect the definite order of bases (Adenosine, Guanine, Thymine and Cytosine) with in the DNA. A) Maxim Gilbert Method B) Sanger Method These are the...
6. ‘There is a paternity dispute for a child’. Which technique can solve the problem? Discuss the principle involved.
Solution: DNA fingerprinting should be utilised to resolve the dispute. Variable Number of Tandem Repeats (VNTR'S), also known as Mini Satellites, generate a pattern of bands in DNA fingerprinting...
3. Biosphere is:
a. a component in the ecosystem b. composed of the plants present in the soil c. life in the outer space d. composed of all living organisms present on earth which interact with the physical...
5. Define an operon. Giving an example, explain an Inducible operon.
Solution: In 1961, François Jacob and Jacques Monad proposed the operon, which is a cluster of genes with linked functions and is involved in the catabolism or decomposition of lactose. Inducer...
2. Ecotone is:
a. A polluted area b. The bottom of a lake c. A zone of transition between two communities d. A zone of developing community correct option –( c ) explanation – ecotone is a transition area between...
4. Discuss the process of translation in detail.
Solution: The decoding of mRNA to generate an amino acid chain with the help of ribosomes in the cell's cytoplasm is known as translation. Amino acids, m-RNA, t-RNA and Ribosomes are involved in...
3. Give an account of post-transcriptional modifications of a eukaryotic mRNA.
Solution: Chemical adjustments to the initial RNA transcript are known as post-transcriptional modifications. These changes turn a gene into RNA that can be used. The principal transcript (hn-RNA)...
2. During evolution why DNA was chosen over RNA as genetic material? Give reasons by first discussing the desired criteria in a molecule that can act as genetic material and in the light of biochemical differences between DNA and RNA.
Solution: The desired criteria in a molecule that can act as genetic material are 1. It should be chemically and structurally stable. 2. It should be able to duplicate in order for replication to...
1. Give an account of the Hershey and Chase experiment. What did it conclusively prove? If both DNA and proteins contained phosphorus and sulphur do you think the result would have been the same?
Solution: In 1952, Alfred Hershey and Martha Chase worked with the virus bacteriophages to detect the presence of genetic material. They took the virus and grew it in two distinct mediums, one of...
23. Comment on the utility of variability in the number of tandem repeats during DNA fingerprinting.
Solution: Tandems are chromosome regions in which the DNA stretch sequence is repeated numerous times. It creates a pattern of bands that is unique to each individual and is utilised in forensic DNA...
22. Do you think that the alternative splicing of exons may enable a structural gene to code for several isoproteins from the same gene? If yes, how? If not, why so?
Solution: Gender-specific exon splicing, developmental stage-specific exon splicing, and so on. This can result in a single gene encoding several proteins. In the absence of such splicing, each...
One of the modes of Asexual reproduction includes binary
i. Fusion of non-somatic cells takes place. ii. Transferring of genetic material takes place. iii. Cells follow the pattern of reductional division. iv. Offspring resembles the parents up to some...
21. What are the functions of (i) methylated guanosine cap, (ii) poly-A “tail” in a mature on RNA?
Solution: (i) Methylated guanosine cap: When a translation is started, methylated guanosine cap assists to bind mRNA to smaller ribosomal subunits. (ii) poly-A “tail”: It prolongs mRNA’s...
20. What background information did Watson and Crick have made available for developing a model of DNA? What was their contribution?
Solution: 1. Chargaffs law showed Adenosine forms bond with Thymine (A&T) and Guanine bonds with Cytosine (G & C). 2. The states of Wilkin and Franklin Each turn of the spiral has a diameter...
19. During in vitro synthesis of DNA, a researcher used 2’, 3’ – dideoxy cytidine triphosphate as raw nucleotide in place of 2’-deoxycytidine. What would be the consequence?
Solution: Because there is no 3'OH group on the sugar to add a nucleotide for generating ester linkages, polymerisation will not occur.
The term ‘clone’ can only be applied to offspring formed by asexual reproduction and not sexual reproduction because:
a. DNA of parent and offspring are completely different. b. Genetic material of none of the parents is copied and passed on to the offspring c. Offspring are formed at different times of the cell...
18. Would it be appropriate to use DNA probes such as VNTR in DNA fingerprinting of a bacteriophage?
Solution: DNA fingerprinting is not an option since it lacks the repetitive sequencing parts for bacteriophage seen in VNTR'S, preventing the formation of a pattern of bands. The bacteriophage...
17. Now, the sequencing of total genomes is getting less expensive day by the day. Soon it may be affordable for a common man to get his genome sequenced. What is your opinion could be the advantage and disadvantage of this development?
Solution: Advantages 1. It would lead to improved genetic condition diagnosis, treatment, and prevention. 2. A better grasp of the DNA gene sequence might aid in the comprehension of biological...
16. The total number of genes in humans is far less (< 25,000) than the previous estimate (up to 1,40,000 gene). Comment.
Solution: The presence of vast amounts of repeated sequencing sequences in the human genome explains this. If the repeating portions of the DNA sequence are not inserted, the non-repetitive gene...
15. How has the sequencing of the human genome opened new windows for the treatment of various genetic disorders? Discuss amongst your classmates.
Solution: Because it resulted in a better understanding of genetic illnesses, the sequencing of the human genome opened new doors for the treatment of many genetic disorders. It is possible to gain...
14. A low level of expression of lac operon occurs at all the time. Can you explain the logic behind this phenomenon?
Solution: Lactose in the external medium can only enter the bacteria if the bacterium contains permease. The lac operon must be expressed at a low level for permease to develop within the bacteria.
13. A single base mutation in a gene may not ‘always’ result in loss or gain of function. Do you think the statement is correct? Defend your answer.
Solution: Yes. Because mutation at the third base pair does not result in phenotypic change, the assertion is valid. Silent mutations are the name given to these mutations.
12. There is only one possible sequence of amino acids when deduced from given nucleotides. But multiple nucleotides sequence can be deduced from a single amino acid sequence. Explain this phenomenon.
Solution: More than one codon codes for several amino acids. The degeneracy of codon is the name given to this event. As a result, numerous nucleotide sequences could be derived from such amino...
11. You are repeating the Hershey-Chase experiment and are provided with two isotopes: 32P and 15N (in place of 35S in the original experiment). How do you expect your results to be different?
Solution: 15N is non-radioactive, while 32P is radioactive. As a result, its presence will go undetected. If 15N were hypothetically radioactive, its presence would be visible both inside the cell,...
10. Recall the experiments done by Frederick Griffith, Avery, MacLeod and McCarty, where DNA was speculated to be the genetic material. If RNA, instead of DNA was the genetic material, would the heat-killed strain of Pneumococcus have transformed the R-strain into virulent strain? Explain.
Solution: The R-strain would not have been converted into the virulent strain if the Pneumococcus strain had been heat-killed. This is due to the fact that RNA is not thermostable.
9. What would happen if histones were to be mutated and made rich in acidic amino acids such as aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?
Solution: Histones would become acidic and negatively charged as a result of this mutation, and they would be unable to attach to DNA because both would be negatively charged. As a result, the DNA...
8. In an experiment, DNA is treated with a compound which tends to place itself amongst the stacks of nitrogenous base pairs. As a result of this, the distance between two consecutive base increases from 0.34nm to 0.44 nm calculate the length of DNA double helix (which has 2×109 bp) in the presence of saturating amount of this compound.
Solution: Distance between two consecutive base pairs: 0.44 nm or 0.44 x 10-9. Length of the DNA: 2 x 10 9 x 0.44 x 10-9 Length of DNA = 0.88m
7. Retroviruses do not follow central Dogma. Comment.
Solution: Because retroviruses' genetic material is RNA rather than DNA, they do not adhere to central Dogma. With the help of the enzyme reverse transcriptase, this RNA is subsequently turned to...
6. During DNA replication, why is it that the entire molecule does not open in one go? Explain the replication fork. What are the two functions that the monomers (d NTPs) play?
Solution: Because the opening or unwinding of DNA causes stress in the molecule, this is the case. The interaction of the exposed nucleotides causes uncoiled portions to create supercoils. For...
5. Give any six features of the human genome.
Solution: 1. There are approximately 3164.7 million nucleotide bases in the genome. 2. 99.9 % of the nucleotide bases are same in all humans. 3. Dystrophin is the biggest gene, with 2.4 million...
4. Define a cistron. Giving examples differentiate between monocistronic and polycistronic transcription unit.
Solution: Cistron is a section of DNA that contains all of the information for a polypeptide chain. Monocistron is a form of messenger RNA that only codes for one protein and has a single codon....
3. Discuss the significance of heavy isotope of nitrogen in the Meselson and Stahl’s experiment.
Solution: In Meselson and Stahl's experiment, a heavy isotope of nitrogen revealed that the DNA is of intermediate density between N14 and N15. This revealed that the hybrid DNA has one N14 strand...
2. Who revealed the biochemical nature of the transforming principle? How was it done?
Solution: In the years 1933-34, Oswald Avery, Colin McLeod, and Maclyn McCarty experimented to find this genetic material. The biochemicals (DNA, RNA, and Protein) were isolated from the heat-killed...
1. Define transformation in Griffith’s experiment. Discuss how it helps in the identification of DNA as the genetic material.
Solution: Frederick Griffith tested with two strains of Streptococcus Pneumoniae bacterium in 1928. The S-strain (smooth strain) and R-strain (rough strain) were implanted into two distinct mice....
11. Name any three viruses which have RNA as the genetic material.
Solution: 1. Tobacco Mosaic Virus 2. Human- Immuno Deficiency Virus 3. Influenza Virus
10. Name a few enzymes involved in DNA replication other than DNA polymerase and ligase. Name the key functions for each of them.
Solution: Helicases, DNA clamps, and single-stranded binding proteins are all examples of single-stranded binding proteins. Helicases need energy to separate the two DNA strands at the replication...
9. In a nucleus, the number of ribonucleoside triphosphates is 10 times the number of deoxy x10 ribonucleoside triphosphates, but only deoxyribonucleotides are added during the DNA replication. Suggest a mechanism.
Solution: Although there are ten times as many ribonucleoside triphosphates as deoxyribonucleoside triphosphates, only deoxyribonucleotides are added during DNA replication. Only deoxyribonucleoside...
8. Sometimes cattle or even human beings give birth to their young ones that are having extremely different sets of organs like limbs/position of the eye(s) etc. Comment.
Solution: It occurs as a result of uncoordinated gene expression control in gene sets linked to organ development.
7. Based on your understanding of genetic code, explain the formation of any abnormal haemoglobin molecule. What are the known consequences of such a change?
Solution: This aberrant haemoglobin molecule production happens when one codon GAG is replaced by GUG, meaning that adenosine is replaced by uracil in the codon GAG. As a result of this alteration,...
6. What is DNA polymorphism? Why is it important to study?
Solution: DNA polymorphism refers to differences in nucleotide sequence between people. It is critical for genetic variety and extremely useful in criminal instances to identify the perpetrator.
5. Given below is the sequence of the coding strand of DNA in a transcription unit 3 ‘A A T G C A G C T A T T A G G – 5’ write the sequence of a) its complementary strand b) the mRNA
Solution: a) Complementary strand: 5’-T T A C G T C G A T A A T C C-3’ b) the mRNA: 5’ A A U G C A G C U A U U G G-3’
4. What is the cause of discontinuous synthesis of DNA on one of the parental strands of DNA? What happens to these short stretches of synthesized DNA?
Solution: DNA III polymerases can check the freshly produced strand for errors and detect incorrect base insertions. At the replicating fork, an extra problem will emerge. The 5'-3' strand of DNA...
3. The enzyme DNA polymerase in E. coli is a DNA dependent polymerase and also has the ability to proof-read the DNA strand being synthesized. Explain. Discuss the dual polymerase.
Solution: In bacteria, there are three forms of DNA polymerase that add nucleotides in the 5'-3' direction. DNA III polymerases can check the freshly produced strand for errors and detect incorrect...
2. Distinguish between heterochromatin and euchromatin. Which of the two is transcriptionally active?
Solution: Heterochromatin is a dark-colored type of DNA found in the chromosomes that is densely packed. Euchromatin is a light-colored, loosely packed type of DNA found in the chromosomes. DNA...
1. What is the function of histones in DNA packaging?
Solution: A protein called histone wraps itself around DNA. Histones form nucleosomes, which are structural units.
28. In E.coli, the lac operon gets switched on when:
a. lactose is present and it binds to the repressor b. repressor binds to operator c. RNA polymerase binds to the operator d. lactose is present and it binds to RNA polymerase Solution: Option (a)...
27. To initiate translation, the mRNA first binds to:
a. The smaller ribosomal sub-unit, b. The larger ribosomal sub-unit c. The whole ribosome d. No such specificity exists. Solution: Option (a) is the answer.
26. The amino acid attaches to the tRNA at its:
a. 5′ – end b. 3′ – end c. Anticodon site d. DHU loop Solution: Option (b) is the answer.
25. If the base sequence of a codon in mRNA is 5′-AUG-3′, the sequence of
tRNA pairing with it must be: a. 5′ – UAC – 3′ b. 5′ – CAU – 3′ c. 5′ – AUG – 3′ d. 5′ – GUA – 3′ Solution: Option (b) is the answer.
24. The RNA polymerase holoenzyme transcribes:
a. the promoter, structural gene and the terminator region b. the promoter and the terminator region c. the structural gene and the terminator region d. the structural gene only Solution: Option (d)...
23. If the sequence of nitrogen bases of the coding strand of DNA in a
transcription unit is: 5′ – A T G A A T G – 3′, the sequence of bases in its RNA transcript would be; a. 5′ – A U G A A U G – 3′ b. 5′ – U A C U U A C – 3′ c. 5′ – C A U U C A U – 3′ d. 5′ – G U A A...
22. If Meselson and Stahl’s experiment is continued for four generations in
bacteria, the ratio of N15/N15: N15/N14: N14/N14 containing DNA in the fourth generation would be: a. 1:1:0 b. 1:4:0 c. 0:1:3 d. 0:1:7 Solution: Option (d) is the answer.
21. In some viruses, DNA is synthesised by using RNA as a template. Such a
DNA is called: a. A-DNA b. B-DNA c. cDNA d. rDNA Solution: Option (c) is the answer
20. While analysing the DNA of an organism a total number of 5386
nucleotides were found out of which the proportion of different bases were: Adenine = 29%, Guanine = 17%, Cytosine = 32%, Thymine = 17%. Considering the Chargaff’s rule it can be concluded that: a....
19. Which of the following are the functions of RNA?
a. It is a carrier of genetic information from DNA to ribosomes synthesising polypeptides. b. It carries amino acids to ribosomes. c. It is a constituent component of ribosomes. d. All of the above....
18. Which was the last human chromosome to be completely sequenced:
a. Chromosome 1 b. Chromosome 11 c. Chromosome 21 d. Chromosome X Solution: Option (a) is the answer.
17. Which of the following statements is correct about the role of regulatory
proteins in transcription in prokaryotes? a. They only increase expression b. They only decrease expression c. They interact with RNA polymerase but do not affect the expression d. They can act both...
16. Control of gene expression in prokaryotes takes place at the level of:
a. DNA-replication b. Transcription c. Translation d. None of the above Solution: Option (b) is the answer
15. Which of the following steps in transcription is catalysed by RNA
polymerase? a. Initiation b. Elongation c. Termination d. All of the above Solution: Option (b) is the answer.
14. Discontinuous synthesis of DNA occurs in one strand, because:
a. DNA molecule being synthesised is very long b. DNA dependent DNA polymerase catalyses polymerisation only in one direction (5’ → 3’) c. it is a more efficient process d. DNA ligase joins the...
13. DNA is a polymer of nucleotides which are linked to each other by 3’-5’
phosphodiester bond. To prevent polymerisation of nucleotides, which of the following modifications would you choose? a. Replace purine with pyrimidines b. Remove/Replace 3′ OH group in deoxyribose...
12. Who amongst the following scientists had no contribution to the
development of the double-helix model for the structure of DNA? a. Rosalind Franklin b. Maurice Wilkins c. Erwin Chargaff d. Meselson and Stahl Solution: Option (d) is the answer.
11. The human chromosome with the highest and least number of genes in
they are respectively: a. Chromosome 21 and Y b. Chromosome 1 and X c. Chromosome 1 and Y d. Chromosome X and Y Solution: Option (c) is the answer.
10. With regard to mature mRNA in eukaryotes:
a. exons and introns do not appear in the mature RNA b. exons appear but introns do not appear in the mature RNA c. introns appear but exons do not appear in the mature RNA d. both exons and introns...
9. The first genetic material could be:
a. protein b. carbohydrates c. DNA d. RNA Solution: Option (d) is the answer.
8. Which of the following is true with respect to AUG?
a. It codes for methionine only b. It is an initiation codon c. It codes for methionine in both prokaryotes and eukaryotes d. All of the above Solution: Option (d) is the answer.
7. Which of the following statements is the most appropriate for sickle cell
anaemia? a. It cannot be treated with iron supplements b. It is a molecular disease c. It confers resistance to acquiring malaria d. All of the above Solution: Option (d) is the...
6. The promoter site and the terminator site for transcription are located at:
a. 3′ (downstream) end and 5′ (upstream) end, respectively of the transcription unit b. 5′ (upstream) end and 3′ (downstream) end, respectively of the transcription unit c. the 5′ (upstream) end d....
5. The net electric charge on DNA and histones is:
a. both positive b. both negative c. negative and positive, respectively d. zero Solution: Option (c) is the answer.
4. The fact that a purine base always pairs through hydrogen bonds with
a pyrimidine base in the DNA double helix leads to: a. the antiparallel nature b. the semiconservative nature c. uniform width throughout DNA d. uniform length in all DNA Solution: Option (c) is the...
3. Both deoxyribose and ribose belong to a class of sugars called:
a. trioses b. hexoses c. pentoses d. polysaccharides Solution: Option (c) is the answer.
2. A nucleoside differs from a nucleotide. It lacks the:
a. base b. sugar c. phosphate group d. hydroxyl group Solution: Option (b) is the answer.
1. In a DNA strand, the nucleotides are linked together by:
a. glycosidic bonds b. phosphodiester bonds c. peptide bonds d. hydrogen bonds Solution; Option (b) is the answer.
Fill in the blanks
Solution: Pomato is a cross between a potato and a tomato. This is an intergeneric sort of hybrid. Somatic hybridization can result in the formation of pomato. Somatic hybridization is the process...
Name a microbe used for the production of Swiss cheese.
Solution: A microbe that is used for the production of Swiss cheese is Penicillium Sherman which consumes the lactose protein in the cheese to form lactic acid. The production of carbon dioxide in...
What is the group of bacteria found in both the rumen of cattle and stage of sewage treatment?
Solution: Methanogens are the group of bacteria found in both the rumen of cattle and sludge of sewage treatment. Methanogens release methane gas. Microorganisms that create methane as a byproduct...
Give an example of a rod-shaped virus.
Solution: Viruses are typically much smaller than bacteria, with the bulk of them being submicroscopic. Helix symmetry is seen in rod-shaped viruses, An example of the rod-shaped virus is the...
Name any genetically modified crop.
Solution: Genetic modification is a technique that involves adding DNA into an organism's genome. New DNA is put into plant cells to create a GM plant. These cells are then cultivated in tissue...
Match the items in Column ‘A’ and Column ‘B’ and choose the correct answer.
The correct answer is:
a. A-ii, B-iv, C-iii, D-i
b. A-iii, B-iv, C-ii, D-i
c. A-iv, B-i, C-ii, D-iii
d. A-iii, B-ii, C-i, D-iv
Column I A. Ladybird B. Mycorrhiza C. Biological control D. BiogasColumn II i. Methane bacterium ii. Trichoderma iii. Aphids iv. Glomus Solution: The ladybird beetle is a biological pest control...
Match the following list of bioactive substances and their roles:
Choose the correct match:
a. A-ii, B-iii, C-i, D-iv
b. A-iv, B-ii, C-i, D-iii
c. A-iv, B-i, C-ii, D-iii
d. A-iii, B-iv, C-ii, D-i
Bioactive Substance A. Statin B. Cyclosporin A C. Streptokinase D. LipaseRole i. Removal of oil stains ii. Removal of clots from blood vessels iii. Lowering of blood cholesterol iv....
Match the following list of bacteria and their commercially important products:
Choose the correct match:
a. A-ii, B-iii, C-iv, D-i
b. A-ii, B-iv, C-iii, D-i
c. A-iv, B-iii, C-ii, D-i
d. A-iv, B-i, C-iii, D-ii
Bacterium A. Aspergillus niger B. Acetobacter aceticC. Clostridium bretylium D. LactobacillusProduct i. Lactic acid ii. Butyric acid iii. Acetic acid iv. Citric acid Aspergillus niger is...
What are three options to increase food production? Discuss each giving the salient features, merits and demerits.
Solution: The three options to increase food production are- Using Multiple Ovulation Embryo Transfer Technology to boost food production is one option. The demerits of this method is- Multiple...
Discuss how the property of plant cell totipotency has been utilized for plant propagation and improvement
Solution: During the 1950s, scientists discovered that an explant can be used to grow an entire plant. Explant refers to any component of a plant that has been cultivated in a test tube under...
(a) Mutations are beneficial for plant breeding. Taking an example, justify the statement.
(b) Discuss briefly the technology that made us self-sufficient in food production.
Solution: (a) The mutation is processed, allowing the plant's genetic sequence to be altered. Mutations can happen naturally or be produced. Mutations in the mung bean induced resistance to yellow...
Does apiculture offer multiple advantages to farmers? List its advantages if it is located near a place of commercial flower cultivation.
Solution: Apiculture is the maintenance of hives of honeybees for the production of honey. It is also known as beekeeping. Farmers can benefit from apiculture in a variety of ways. The following are...
‘Modern methods of breeding animals and plants can alleviate the global food shortage’. Comment on the statement and give suitable examples.
Solution: The claim that contemporary ways of growing animals and plants can help ease the global food deficit is valid. When we compare the state of food security during World War II to the current...
What are the advantages of tissue culture methods over the conventional method of plant breeding in crop improvement programmes?
Solution: In crop improvement programs, tissue culture has the following advantages over traditional plant breeding methods: i. Any portion of the parent plant can be used to...
(a) The shift from grain to meat diets creates more demands for cereals. Why?
(b) A 250 kg cow produces 200 g of protein per day but 250 g of Methylophillusmethylotrophus can produce 25 tonnes of protein Name this emerging area of research. Explain its benefits.
Solution: (a) We know that an organism at a specific trophic level consumes 90% of the biomass it consumes for its own needs, leaving just 10% for the creature at the next trophic level. So, to...
You are a Botanist working in the area of plant breeding. Describe the various steps that you will undertake to release a new variety.
Solution: When a botanist works in the field of plant breeding and development, there are a few processes that must be followed. Various strategies can be used to create a new plant variety. The...
Give a few examples of biofortified crops. What benefits do they offer to society?
Solution: Golden rice (fortified with vitamin A, iron, and zinc), sweet potato (fortified with beta carotene), vitamin A enriched carrot, iron-enriched bitter gourd, and other biofortified crops....
What are the physical barriers of a cell in the protoplast fusion experiment? How are the barriers overcome?
Solution: The physical barrier that prevents protoplast fusion is the cell wall. With the help of the enzymes cellulase and pectinase, the cell wall, which is made up of cellulose and pectin, is...
Discuss briefly how pure lines are created in animal husbandry.
Solution: Pure line is a breed or strain of plants and animals that have homozygous alleles and have similar characters for various generations. In-breeding is used to establish pure lineages....
Discuss natural selection and artificial selection. What are the implications of the latter on the process of evolution?
Solution: Natural selection and Artificial selection are defined as- Natural Selection: Nature picks creatures with desirable characteristics, as the term implies. Organisms that are better adapted...
Define the term ‘stress’ for plants. Discuss briefly the two types of stress encountered by plants.
Solution: Any unfavorable influence on the plant generated by any reason, whether biotic or abiotic, is referred to as stress. Stress has an impact on the plant's growth and development. Water...
Discuss the importance of testing of new plant varieties in a geographically vast country like India.
Solution: India is a huge country with a lot to offer. Different soil types and climatic conditions can be found in different sections of the country. To be successful throughout India, a crop...
Plants raised through tissue cultures are clones of the ‘parent’ plant. Discuss the utility of these plants.
Solution: Tissue culture is a technique that allows us to grow thousands of identical plants from a single cell. Tissue culture plants are used to make thousands and thousands of perfect duplicates...
What is the difference between a breed and a species? Give an example for each category.
Solution: A breed is a group of animals with similar appearance, behavior, and other characteristics, whereas a species is a collection of plants and animals that live together and can reproduce...
5. Define aneuploidy. How is it different from polyploidy? Describe the individuals having following chromosomal abnormalities.
a. Trisomy of 21st Chromosome b. XXY c. XO Solution: Aneuploidy occurs when chromatid segregation fails during the cell division cycle, resulting in the gain or loss of a chromosome(s). Polyploidy...
4. Discuss in detail the contributions of Morgan and Sturvant in the area of genetics.
Solution: Hunt, Thomas Morgan and his colleagues carried out multiple dihybrid crosses of drosophila to examine the sex-linked genes and experimentally proved the theory of inheritance. Example:...
3. A normal visioned woman, whose father is colour blind, marries a normal visioned man. What would be the probability of her sons and daughters to be colour blind? Explain with the help of a pedigree chart.
Solution: Color blindness is a disorder that can be handed down through the generations .
2. a. In humans, males are heterogametic and females are homogametic. Explain. Are there any examples where males are homogametic and females heterogametic?
b. Also describe as to, who determines the sex of an unborn child? Mention whether the temperature has a role in sex determination. Solution: Humans have XY chromosomes that determine their gender....
1. In a plant, tallness is dominant over dwarfness and red flower is dominant over white. Starting with the parents work out a dihybrid cross. What is the standard dihybrid ratio? Do you think the values would deviate if the two genes in question are interacting with each other?
Solution:
15. It is said, that the harmful alleles get eliminated from the population over some time, yet sickle cell anaemia is persisting in the human population. Why?
Solution: The human population still has sickle cell anaemia. It affects people who have mutations in both their maternal and paternal haemoglobin genes. The patients are more protected against...
14. With the help of an example differentiate between incomplete dominance and co-dominance.
Solution: It creates a combination of the expression of two alleles in partial dominance, and the F1 does not resemble either of the parents. Flower colour in a dog flower is an example. There is no...
13. What is artificial selection? Do you think it affects the process of natural selection? How?
Solution: It is a type of selection in which people choose desired features or a mix of traits in order to take advantage of species differences. Only in plants does the process of natural selection...
12. What is recombination? Discuss the applications of recombination from genetic engineering.
Solution: Recombination is the process of creating non-parental gene combinations through cross-over or independent selection. Alfred Sturtevant calculated the distance between gene pairs on the...
11. How do genes and chromosomes share similarity from genetical studies?
Solution: 1. It both occurs in pair 2. Genes and chromosomes separate during gamete development, and one of each pair is passed to a gamete. 3. The pairs will independently separate each...
10. Discuss why Drosophila has been used extensively for genetical studies.
Solution: Because it is a simple synthetic medium that can be cultivated in the laboratory, Drosophila has been utilised extensively for genetic studies. A single mating can result in a vast number...
9. If a father and son are both defective in red-green colour vision, is it likely that the son inherited the trait from his father? Comment.
Solution: Color blindness is a frequent genetic illness, meaning it is handed down from one generation to the next. When a father is colorblind, his daughter can only inherit an X chromosome. As a...
7. In peas, tallness is dominant over dwarfness, and red colour of flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated with a dwarf plant bearing white flowers, the different phenotypic groups were obtained in the progeny in numbers mentioned against them:
Tall, Red = 138 Tall, White = 132 Dwarf, Red = 136 Dwarf, White = 128 Mention the genotypes of the two parents and the four offspring types. Solution:
6. What are the characteristic features of a true-breeding line?
Solution: It boosts the organism's homozygozity. Through deletion, this also aids in the elimination of dangerous recessive genes. As a result, it encourages the accumulation of superior genes.
5. A plant with red flowers was crossed with another plant with yellow flowers. If F1 showed all flowers orange in colour, explain the inheritance.
Solution: Incomplete dominance is the inheritance. F1 had a phenotype that was in between the parent plants and did not resemble either of them.
4. How was it concluded that genes are located on chromosomes?
Solution: Morgan confirmed Mendelian inheritance laws as well as the fact that genes are found on the same chromosomes. In Drosophila, he discovered that eye colour was a sex-linked feature....
3. What is Down’s syndrome? Give its symptoms and cause. Why is it that the chance of having a child with Down’s syndrome increases if the age of the mother exceeds forty years?
Solution: The presence of an extra copy of chromosomal number 21 (9trisomy of 21) causes Down syndrome. 23 pairs of autosomes and 1 pair of sex chromosomes make up the karyotype. (There are a total...
2. Can a child have blood group O if his parents have blood group ‘A’ and ‘B’? Explain.
Solution: Yes, a child can have blood group O if both of his parents have blood groups A and B. The gene I controls ABO blood grouping in humans. IA, IB, and I are the three alleles of the gene (I)....
1. In a Mendelian monohybrid cross, the F2 generation shows identical genotypic and phenotypic ratios. What does it tell us about the nature of alleles involved? Justify your answer.
Solution: Starting with homozygous dominant and homozygous recessive parents in a monohybrid cross, F1 with partial dominance can show identical genotypic and phenotypic ratios.
15. How does a mutagen induce mutation? Explain with example.
Solution: A mutagen can alter the alignment and content of nitrogen bases in DNA, resulting in a different gene product and therefore mutation.
14. Even if a character shows multiple allelism, an individual will only have two alleles for that character. Why?
Solution: A diploid organism has more than two alleles, and each character has two alleles. Multiple alleles can be discovered in population research.
13. Discuss the genetic basis of wrinkled phenotype of pea seed.
Solution: The tiny grain size produced by a double recessive allele is the genetic basis for the wrinkled phenotype of pea seed.
2. In our society, a woman is often blamed for not bearing a male child. Do you think it is right? Justify.
Solution: The father, not the mother, determines the baby's sex. The X chromosome is carried by 50% of sperm while the Y chromosome is carried by 50% of sperm. After fusing, the zygote has XX or YY...
11. A, B, D are three independently assorting genes with their recessive alleles a, b, d, respectively. A cross was made between individuals of Aa bb DD genotype with aa bb dd. Find out the type of genotypes of the offspring produced.
Solution: The given cross is Aa bb DD X aa bb dd. Hence the offspring’s would be:
10. For the expression of traits, genes provide only the potentiality and the environment provides the opportunity. Comment on the veracity of the statement.
Solution: Individual phenotype is the product of the interaction of environment and genotype. Phenotype = Genotype + Environment
9. In a monohybrid cross of plants with red and white-flowered plants, Mendel got only red-flowered plants. On self-pollinating these F1 plants got both red and white-flowered plants in 3:1 ratio. Explain the basis of using RR and rr symbols to represent the genotype of plants of the parental generation.
Solution: Mendel obtained only red-flowered plants with genotype Rr by crossing red (RR) and white (rr) flowering plants. This is the first hybrid generation's filial progeny (F1) or plants. F1...
8. How are the alleles of a particular gene differ from each other? Explain its significance.
Solution: Homozygous means that the allelic pairings of a gene are same, whereas heterozygous means that the allelic pairs of a gene are different. A dominant factor is one of two distinct factors,...
“Give me a living cell of any plant and I will give you a thousand plants of the same type” Is this only a slogan or is it scientifically possible? Write your comments and justify them.
Solution: Tissue culture, we know, has made it feasible to grow a new plant from any portion of an existing one. Tissue culture is the method through which we can produce thousands of plants of the...
7. Genes contain the information that is required to express a particular trait.” Explain.
Solution:
Is there any relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments?
Solution: Meristematic tissue cells undergo differentiation and lose their ability to divide in order to create permanent tissue, as we know. Plants, on the other hand, have the rare capacity to...
6. To obtain the F1 generation Mendel pollinated a pure-breeding tall plant with a pure breeding dwarf plant. But forgetting the F2 generation, he simply self-pollinated the tall F1 plants. Why?
Solution: Because of true breeding, Mendel pollinated a pure-breeding tall plant with a pure-breeding dwarf plant to produce the F1 generation. Half of the kids of a genotype resemble one parent,...
The culture medium (nutrient medium) can be referred to as a ‘highly enriched laboratory soil. Justify the statement.
Solution: A culture media is a growth medium that has been artificially created. This medium contains a variety of nutrients, chemicals, growth regulators, and food supplements that the growing cell...
5. The pedigree chart given below shows a particular trait which is absent in parents but present in the next generation irrespective of sexes. Draw your conclusion based on the pedigree.
Solution: According to the pedigree, both parents are carriers, and only a handful of the kids exhibit the feature that is gender agnostic. The other could be normal or a carrier.
It is easier to culture plant cells in vitro as compared to animal cells. Why?
Solution: Plant cells can be cultured in vitro more easily than animal cells. The reasons behind this are as follows: (a) Meristem is present in a plant, and meristem cells are always divided....
4. A person has to perform crosses to study the inheritance of a few traits/characters. What should be the criteria for selecting the organisms?
Solution: True breeding is the criterion for selecting the organisms.
3. Enlist the steps of controlled cross-pollination. Would emasculation be needed in a cucurbit plant? Give reasons for your answer.
Solution: 1. Selection of parents with desired characters 2 Emasculation and bagging procedures protect the stigma against contamination (unwanted pollen grains). Cucurbits are monoecious...
Suggest some of the features of plants that will prevent insect and pest infestation.
Solution: Morphological features: Various plants have a certain hair-like structure in the stem and other parts of the plants, these features prevent insect pests and Biochemical features...
2. Do you think Mendel’s laws of inheritance would have been different if the characters that he chose were located on the same chromosome?
Solution: Even if the characteristics were on the same chromosome, Mendel's rules of inheritance would not have been different because Mendel's laws of inheritance would not have been different even...
Name the improved characteristics of wheat that helped India to achieve a green revolution.
Solution: The improved qualities of wheat that helped India accomplish the green revolution were as follows: (a) Semi-dwarf plants: Semi-dwarf plants use the majority of their resources to produce a...
1. What is the cross between the progeny of F1 and the homozygous recessive parent called? How is it useful?Solution:
The Test cross is a cross between F1 progeny (that is, F2 generation) and a homozygous recessive parent that is used to determine the genotype (genetic makeup) of a plant whose phenotype (visible...
18. Mother and father of a person with ‘O’ blood group have ‘A’ and ‘B’ blood
group, respectively. What would be the genotype of both mother and father? a. Mother is homozygous for ‘A’ blood group and father is heterozygous for ‘B’ b. Mother is heterozygous for ‘A’ blood...
What is meant by germplasm collection? What are its benefits?
Solution: Germplasm is nothing more than a collection of genes. The collection of plants or seeds that include all of the various alleles for all of the genes in a specific crop is completed. The...
17. In the F2 generation of a Mendelian dihybrid cross the number of
phenotypes and genotypes are: a. phenotypes – 4; genotypes – 16 b. phenotypes – 9; genotypes – 4 c. phenotypes – 4; genotypes – 8 d. phenotypes – 4; genotypes – 9Solution: Option (d) is the...
How can we improve the success rate of fertilization during artificial insemination in animal husbandry programmes?
Solution: Multiple Ovulation Embryo Transfer Technique (MOET) is used to improve fertilizing success rates. A cow is given an FSH-like activity hormone to enhance follicular maturation and...
16. Two genes ‘A’ and ‘B’ are linked. In a dihybrid cross involving these two
genes, the F1 heterozygote is crossed with the homozygous recessive parental type (aa bb). What would be the ratio of offspring in the next generation? a. 1: 1 : 1: 1 b. 9 : 3 : 3: 1 c. 3: 1 d. 1: 1...
Lifestyle diseases are increasing alarmingly in India. We are also dealing with large scale malnutrition in the population. Is there any method by which we can address both of these problems together?
Solution: Adopting nutritious foods can help prevent both malnutrition and lifestyle problems. As part of an overall healthy diet, eating a diet high in various vegetables and fruits may protect...
15. It is said that Mendel proposed that the factor controlling any character
is discrete and independent. His proposition was based on the a. results of the F3 generation of a cross. b. observations that the offspring of a cross made between the plants having two contrasting...
A farmer was facing the problem of low yield from his farm. He was advised to keep a beehive in the vicinity. Why? How would the beehive help in enhancing yield?
Solution: It appears that the low yield from the farm was because of the absence of sufficient pollinators. We know pollination is important for seed production in many crops. Insects are important...
14. The inheritance pattern of a gene over generations among humans is
studied by the pedigree analysis. Character studied in the pedigree analysis is equivalent to: a. quantitative trait b. Mendelian trait c. polygenic trait d. maternal trait Solution: Option (b) is...
13. In a certain taxon of insects, some have 17 chromosomes and the others
have 18 chromosomes. The 17 and 18 chromosome-bearing organisms are: a. males and females, respectively b. females and males, respectively c. all males d. all females Solution: Option (a) is the...
Explain the concept of the Blue Revolution.
Solution: The rise of aquaculture as a significant and highly productive agricultural activity is referred to as the 'blue revolution.' Its vision is to achieve economic prosperity for the country,...
12. Occasionally, a single gene may express more than one effect. The
the phenomenon is called: a. multiple allelism b. mosaicism c. pleiotropy d. polygeny Solution: Option (c) is the answer.
11. Mendel’s Law of independent assortment holds good for genes situated
on the: a. non-homologous chromosomes b. homologous chromosomes c. extranuclear genetic element d. same chromosome Solution: Option (b) is the answer.
It is said, that diseases are spreading faster due to globalization and increased movement of people. Justify the statement taking the example of the H5N1 virus.
Solution: Globalization is aided by migration from one location to another. As a result, there is a greater risk of infectious diseases spreading quickly. The virus can even spread from person to...
10. Which of the following will not result in variations among siblings?
a. Independent assortment of genes b. Crossing over c. Linkage d. Mutation Solution: Option (c) is the answer
9. In a dihybrid cross, if you get 9:3:3:1 ratio it denotes that:
a. The alleles of two genes are interacting with each other b. It is a multigenic inheritance c. It is a case of multiple allelism d. The alleles of two genes are segregating independently Solution:...
You are planning to set up a Dairy Farm. Describe the various aspects you would consider before you start the venture. Solution: Before launching the business, keep the following factors in mind:
(i) Breed Selection: The breed should be capable of producing a high milk output. It should be able to fend off a variety of ailments. (ii) Cattle shed construction: Cattle sheds should be well...
8. A cross between two tall plants resulted in offspring having few dwarf
plants. What would be the genotypes of both the parents? a. TT and Tt b. Tt and Tt c. TT and TT d. Tt and tt Solution: Option (b) is the answer.
The term ‘desirable trait’ can mean different things for different plants. Justify the statement with suitable examples.
Solution: If the character of height is taken into consideration, tallness can be desirable for one plant whereas undesirable for another plant. The same is the case with dwarfness. (a) While a...
7. Z Z / ZW type of sex determination is seen in:
a. Platypus b. Snails c. Cockroach d. Peacock Solution: Option (d) is the answer.
6. The person having genotype IA IB would show the blood group as AB. This is
because of: a. Pleiotropy b. Co-dominance c. Segregation d. Incomplete dominance Solution: Option (b) is the answer.
Give two important contributions of Dr M. S. Swaminathan.
Solution: The two contributions of Dr. M. S. Swaminathan are- (i) M.S. Swaminathan produced high-yielding, short-duration rice cultivars, notably scented Basmati. He is known as the ‘Father of Green...
5. In sickle cell anaemia glutamic acid is replaced by valine. Which one of
the following triplets codes for valine? a. G G G b. A A G c. G A A d. G U G Solution: Option (d) is the answer.
Differentiate between pisciculture and aquaculture.
Solution: Pisciculture is the culture of just fishes to obtain products of fish whereas aquaculture is the culture of all aquatic plants and animals. Aquaculture - Fish is a high-protein food with a...
4. If a genetic disease is transferred from a phenotypically normal but carrier
female to only some of the male progeny, the disease is: a. Autosomal dominant b. Autosomal recessive c. Sex-linked dominant d. Sex-linked recessiveSolution: Option (d) is the answer.
3. Distance between the genes and the percentage of recombination shows:
a. a direct relationship b. an inverse relationship c. a parallel relationship d. no relationship Solution: Option (a) is the answer.
2. Conditions of a karyotype 2n +1, 2n –1 and 2n + 2, 2n – 2 are called:
a. Aneuploidy b. Polyploidy c. Allopolyploidy d. Monosomy Solution: Option (a) is the answer.
Interspecific crosses are rare in nature and intergeneric crosses almost unknown. Why?
Solution: In the interspecific crossing, two different male and female species mate. The offspring produced in this manner will be sterile. As a result, inter-specific crosses are rare in nature....
Discuss the two main limitations of a plant hybridization programme.
Solution: The following are the two main limits of the plant hybridization program: (a) Germplasm collection: Cultivators and agricultural scientists require seeds from currently produced kinds as...
1. All genes located on the same chromosome:
a. Form different groups depending upon their relative distance b. Form one linkage group c. Will not from any linkage groups d. Form interactive groups that affect the phenotype Solution: Option...
What is emasculation? Why and when is it done?
Solution: Emasculation is the process of removing the male portion of a bisexual flower, the anther. The male reproductive component (stamens) of a flower, usually a bisexual flower, is...
How is a somatic hybrid different from a hybrid?
Solution: The fusion of any two organisms produces a somatic hybrid, whereas the fusion of two different varieties or two related species produces a hybrid. Nuclear and cytoplasmic fusion occurs as...
Would it be wrong to call plants obtained through micro-propagation as ‘clone’? Comment.
Solution: No, it is not incorrect because each plant will be genetically identical to the original plant from which it was developed, i.e., clones/soma clones. A clone is a live entity that is...