Q1
mcq
1 mark
When a pollen tube emerges from the germinating pollen grain, it carries along with it :
- A. cytoplasm, vegetative cell and generative cell
- B. cytoplasm and generative cell
- C. cytoplasm and vegetative cell
- D. cytoplasm, vegetative cell and one male gamete
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Q2
mcq
1 mark
Scutellum in maize grain represents :
- A. Endosperm
- B. Cotyledon
- C. Embryo
- D. Coleoptile
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Q3
mcq
1 mark
Tightly linked genes on the same chromosome lead to :
- A. very low recombination
- B. very high recombination
- C. no recombination
- D. non-parental combination
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Q4
mcq
1 mark
The type of sex determination in honeybee is referred to
- A. Diplodiploid
- B. Haplodiploid
- C. Haplodiploidy
- D. Diplohaplodiploid
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Q5
mcq
1 mark
The type of plants found during Mesozoic era in which dinosaurs flourished were :
- A. Progymnosperms
- B. Tracheophytes
- C. Bryophytes
- D. Conifers
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Q5
mcq
The type of plant forms that existed along with dinosaurs are :
- A. Progymnosperms
- B. Tracheophytes
- C. Bryophytes
- D. Conifers
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Q6
mcq
1 mark
Resistance to antiobiotics in bacteria increase when they are exposed to antibiotics for a long time because of :
- A. changes in their genes
- B. natural selection of resistant bacteria
- C. adaptation
- D. unfavourable mutations
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Q6
mcq
Overuse of antibiotics has increased resistance in bacteria in a very short span of time due to :
- A. chance mutations
- B. the role played by selection of resistant varieties
- C. adaptive evolution
- D. divergent evolution
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Q7
mcq
1 mark
Which one of the following options is an example of polygenic inheritance?
- A. sugar content in sugarcane
- B. ABO blood groups in humans
- C. flower colour in Mirabilis jalapa
- D. height in humans
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Q13
mcq
Assertion (A): The embryo in a seed may enter a state of inactivity called dormancy. Reason (R): This state occurs when all conditions are favourable.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q14
mcq
Assertion (A): DNA is a long polymer of deoxyribonucleotides. Reason (R): Polymer of N-base + deoxyribose sugar + phosphate with free phosphate moiety at 5 end of deoxyribose sugar that is referred to as the 5 end of the polymer has a free OH at 3 end of the deoxyribose sugar, referred to as 3 end of the polymer.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q15
mcq
Assertion (A): Malaria is caused by female Anopheles mosquito. Reason (R): The female Anopheles mosquito requires human blood to produce eggs.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q16
mcq
Assertion (A): Adenosine deaminase (ADA) deficiency causes severe disorders in humans as ADA is crucial for the immune system to function. Reason (R): This can be treated permanently by bone marrow transplantation in adult humans.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q21
short answer
2 marks
(a) A number of insects are feeding on a big tree which are being fed by small birds. The small birds are being preyed upon by large birds. (i) Name the different trophic levels in this situation. (ii) Mention the types of pyramids that can be formed based on the biomass and the number respectively in the above situation.
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Q21
short answer
2 marks
OR (b) State the effect of the following on the rate (both low and high) of decomposition of detritus: (i) Composition of detritus (ii) Climatic factors
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Q22
short answer
3 marks
(a) Where and when does corpus luteum develop in a human female? Name the hormone and its source gland, that influences its development. (b) State the role of corpus luteum during: (i) Menstrual cycle (ii) Pregnancy
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Q23
short answer
3 marks
Where does fertilisation occur in a human female? Explain the process of fertilisation.
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Q24
short answer
3 marks
A colour blind son and a daughter with normal vision are born to a couple. Explain the inheritance of this trait in this family.
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Q25
short answer
3 marks
What are fossils? How do fossils help to understand the process of evolution?
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Biotechnology is based on the manipulation of the genes either by addition of a desirable gene or deletion of an undesirable gene from the genome of an organism. This genetic engineering is carried out keeping the welfare of the humans in mind.
Q25
short answer
1 mark
Write the specific sequence of nucleotides that are recognised by EcoRI on a DNA segment. Where in this sequence does EcoRI make its cut? Also mention the two ends produced in the sugar-phosphate backbone of the DNA?
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Q26
short answer
3 marks
Name any three enzymes obtained from microbes and mention the role played by them in human welfare.
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Q26
short answer
2 marks
List the five tools generally used in genetic engineering.
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Q27
short answer
3 marks
(a) Write the steps that would be followed to develop a bollworm-resistant cotton crop plant.
OR
(b) How does silencing of mRNA prevent infestation of tobacco plants by Meloidogyne incognitia? Explain.
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Q27
short answer
1 mark
Name a synthetic/engineered vector. Why does it have multiple restriction sites in it?
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Q28
short answer
3 marks
Biodiversity exists at all levels of biological organisation ranging from macromolecules within cells to biomes. Explain the three most important levels of biodiversity with the help of one example from each.
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All living beings including humans are interdependent and can never exist in isolation. In this web of interdependence, organisms tend to develop various kinds of interactions where some benefit, others are harmed and still many others remain
Q28
short answer
2 marks
Name the specific type of interaction that exists between a cuckoo and a crow during their breeding season. Mention the role of each one in this interaction.
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Biotechnology is based on the manipulation of the genes either by addition of a desirable gene or deletion of an undesirable gene from the genome of an organism. This genetic engineering is carried out keeping the welfare of the humans in mind.
Q29
short answer
(a) Write the specific sequence of nucleotides that are recognised by EcoRI on a DNA segment. Where in this sugar-phosphate backbone of the DNA does EcoRI cut this specific nucleotide sequence?
(b) List the five tools generally used in genetic engineering.
OR
(b) List the five tools generally used in genetic engineering.
(c) Name a synthetic/engineered vector. Why does it have multiple restriction sites in it?
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Q29
long answer
5 marks
Describe the process of double fertilisation in angiosperms.
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All living beings including humans are interdependent and can never exist in isolation. In this web of interdependence, organisms tend to develop various kinds of interactions where some benefit, others are harmed and still many others remain
Q30
long answer
5 marks
Explain the process of development of endosperm in a coconut.
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Q31
long answer
5 marks
Describe the process of spermatogenesis in humans.
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Q32
long answer
5 marks
Name the hormones and mention their roles in the regulation of the process of spermatogenesis.
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Q34
long answer
5 marks
With the help of a suitable example from humans, explain point mutation and mention the symptoms that appear due to this mutation.
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Q36
long answer
5 marks
Describe the experiment performed by Meselson and Stahl. Write the conclusion at which they arrived, at the end of their experiment.
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Q37
long answer
5 marks
State what is innate immunity. Write any four ways in which it is accomplished in a human body.
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Q38
long answer
5 marks
Name the parasite that causes malaria in humans (scientific name). How does the parasite gain entry into the human body? Explain the parasitic cycle in the human body that causes the disease.
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Q39
long answer
5 marks
Write the symptoms of the disease and mention what causes them to appear.
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