Q1
mcq
1 mark
Human placenta acts as an endocrine tissue and produces some hormones. Identify the hormone which is not produced by the placenta during pregnancy.
- A. Estrogen
- B. h
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Q2
mcq
1 mark
Pistil-pollen interaction is mediated in a flower due to which of the following factors?
- A. Chemical components
- B. Water availability
- C. Length of light exposure
- D. Humidity
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Q3
mcq
1 mark
Identify the amino acid residues that are present in histones of a nucleosome.
- A. Serine and Lysine
- B. Cystine and Arginine
- C. Alanine and Lysine
- D. Lysine and Arginine
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Q4
mcq
1 mark
Identify that ancestor of man who lived in East African Grasslands, hunted with stone weapons and used to eat fruits.
- A. Homo habilis
- B. Dryopithecus
- C. Australopithecines
- D. Homo erectus
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Q5
mcq
1 mark
Choose the option from the following that could be the reason for sickle cell anemia:
- A. Frameshift mutation
- B. Point mutation
- C. Exposure to dust particles
- D. Mutation caused due to a change in number of the chromosome
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Q6
mcq
1 mark
In honey bee, haplodiploid sex determination takes place. Choose the correct statement from the following:
- A. Females are mostly haploid.
- B. Males produce haploid sperms by meiosis.
- C. Males do have fathers and thus can have sons.
- D. Unfertilised egg develops as a male (drone) by means of parthenogenesis.
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Q7
mcq
1 mark
During cell division, polyploidy is caused due to which process? Select the option that indicates the correct process.
- A. Gain of a chromosome
- B. Loss of a chromosome
- C. Abnormal arrangement of a chromosome
- D. Increase in a whole set of chromosomes
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Q8
mcq
1 mark
When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters. The above statement
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Q8
mcq
“When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters.” The above statement explains which of the following law/principle of Mendel ?
- A. Principle of dominance
- B. Principle of paired factors
- C. Law of independent assortment
- D. Law of segregation
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Q9
mcq
During the process of making curd, an inoculum is added to fresh milk to initiate the process. Choose the option that tells us about ‘inoculum’.
- A. Rich in millions of Lactic Acid Bacteria (LAB)
- B. Having pathogenic microbes
- C. Producing large amount of $\mathrm{CO_2}$
- D. Rich in Vitamin A and Vitamin C
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Q10
mcq
According to the Hardy-Weinberg principle, the sum total of all allelic frequencies in a population is equal to ‘1’ (one). Which factor from the following will not affect this sum total ?
- A. Genetic drift
- B. Mutation
- C. Random mating
- D. Gene flow
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Q11
mcq
The genetic disorder ‘Phenylketonuria’ is an example for which of the following ?
- A. Polygenic inheritance
- B. Pleiotropy
- C. Multiple allelism
- D. Co-dominance
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Q12
mcq
Identify the special type of cells that produce antibodies in our blood in response to pathogen :
- A. T-lymphocytes
- B. Natural killer cells
- C. B-lymphocytes
- D. Both (B) and (C)
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Q17
short answer
2 marks
(a) Answer the following questions : 2
(i) How is the placenta formed in a human female ?
(ii) Give any two functions of the placenta, other than acting as an endocrine tissue.
OR
(b) Answer the following questions : 2
(i) How is the entry of only one sperm, and not many, ensured into an ovum during fertilisation in humans ?
(ii) Write the location and function of Sertoli cells in humans.
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Q18
short answer
2 marks
(a) (i) Mendel published his work on the inheritance of characters in 1865, but for several reasons, it remained unrecognised until 1900. Mention any two reasons.
(ii) Write the observations of Sutton and Boveri. 2
OR
(b) (i) Write the contribution of Thomas Hunt Morgan and his colleagues.
(ii) Why did Morgan choose Drosophila melanogaster to
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Q19
short answer
2 marks
Residents should ensure that there is no stagnation of water in and around their areas.
(a) Name any two diseases for which this is an effective control measure.
(b) How does it act as a control measure?
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Q20
short answer
2 marks
How do ‘molecular scissors’ help in the construction of an artificial recombinant DNA molecule?
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Q21
short answer
2 marks
(a) (i) What is meant by the term ‘standing crop’? How is it measured?
(ii) Which place will have a higher standing crop – a desert or a pond? Why?
OR
(b) (i) What is a trophic level?
(ii) How do decomposers meet their energy and nutritional requirements?
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Q22
short answer
3 marks
(a) Mention the similarity between autogamy and geitonogamy.
(b) How does geitonogamy differ from xenogamy?
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Q23
short answer
3 marks
(a) Name the target cells of Luteinising Hormone (LH) in human males and females.
(b) Explain the effects and the changes induced by LH in human males and females.
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Q24
short answer
3 marks
Provide any three evidences to prove that “evolution of life forms has indeed taken place on Earth” and explain them.
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Q25
short answer
3 marks
Explain the structure and function of that molecule which reads the genetic code and also links it to the amino acids to enable protein synthesis.
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Q26
short answer
3 marks
(a) Why do farmers prefer biofertilisers to chemical fertilisers these days? Explain.
(b) How do mycorrhiza and cyanobacteria act as biofertilisers?
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Q27
short answer
3 marks
‘P’ and ‘Q’ are the two different cloning vectors in two different bacterial colonies cultured in chromogenic substrate. Bacterial colonies with cloning vector ‘P’ were colourless, whereas those with ‘Q’ were blue-coloured. Explain, with reasons, the cause of the difference in colour of bacterial colonies that appeared.
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Q28
short answer
3 marks
Define ‘competition’. Explain how the Abingdon tortoise in Galapagos Islands went extinct. What is competitive release?
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A recent study says that in India, only around one percent of women aged 45 and above undergo mammography periodically. Delays in diagnosis in India, result in more women dying from the disease. Based on the given information, answer the questions below:
Q28
short answer
1 mark
A kin of the victim was asked to give a sample of blood to identify the victim. What is the purpose of this procedure?
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As a result of an earthquake, there was a lot of damage to the property and human life. The extent of the damage occurred to such proportions, that it was impossible to identify the victims.
Q29
long answer
4 marks
(a) Suggest a method to identify the victims. Name the person who initially developed the technique.
(b) In the Southern blot hybridisation process, what is the role of restriction endonucleases and autoradiography ?
(c) (i) A kin of the victim was asked to give a sample of blood to identify the victim. What is the purpose of this procedure ?
OR
(c) (ii) Apart from identifying victims, what other functions are achieved by such techniques ?
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A recent study says that in India, only around one percent of women aged 45 and above undergo mammography periodically. Delays in diagnosis in India, result in more women dying from the disease. Based on the given information, answer the questions below:
Q29
short answer
1 mark
Apart from identifying victims, what other functions are achieved by such techniques?
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A recent study says that in India, only around one percent of women aged 45 and above undergo mammography periodically. Delays in diagnosis in India, result in more women dying from the disease.
Q30
long answer
4 marks
(a) Suggest any two techniques used for cancer detection and diagnosis of the internal organs.
(b) Name the kinds of tumours. Describe them.
(c) (i) Define ‘metastasis’.
OR
(c) (ii) Explain the term ‘contact inhibition’. Which cells exhibit this phenomenon ?
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A recent study says that in India, only around one percent of women aged 45 and above undergo mammography periodically. Delays in diagnosis in India, result in more women dying from the disease. Based on the given information, answer the questions below:
Q30
long answer
4 marks
Read the following passage and answer the questions that follow:
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Q31
short answer
1 mark
Suggest any two techniques used for cancer detection and diagnosis of the internal organs.
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Q32
short answer
2 marks
Name the kinds of tumours. Describe them.
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Q33
long answer
5 marks
Explain any three outbreeding devices in flowering plants.
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Q34
long answer
5 marks
Why do farmers prefer apomictic seeds over hybrid seeds?
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Q35
long answer
5 marks
Where do the signals for parturition originate in humans and how does parturition take place completely? Explain.
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Q36
long answer
5 marks
Why is it important to feed newborn babies on colostrum? Explain.
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Q37
long answer
5 marks
How can a virus-free healthy plant be obtained from a diseased sugarcane plant? Explain.
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Q38
long answer
5 marks
How is Bacillus thuringiensis used as a bio-control agent?
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Q39
long answer
5 marks
Genetically modified (GM) plants are useful in many ways. How would you convince the farmers to grow these plants in their fields? Explain by giving four reasons.
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Q40
long answer
5 marks
What are transgenic animals? Mention any four benefits derived from such animals.
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Q41
long answer
5 marks
How do we find out whether the population is flourishing or declining? Name and explain four basic processes that control it.
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Q42
long answer
5 marks
Suggest and explain any five measures of conservation of biodiversity, so that both development and conservation can occur simultaneously.
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