Term 1 Sample Paper Class 12 Biology 2021-22
Time: 1.30 hour
Note-All the questions bear equal marks. You have to attempt all the questions. Read the question attentively and choose correct answer from the multiple choices given below.
Section A (attempt any 15)
1. Embryo sac is related to ovule as__________ is related to an anther.
c) Pollen grain ✓
2. The coconut water from tender coconut is-
a) cellular endosperm
b) free nuclear endosperm✓
c) both cellular and nuclear endosperm
d) nuclear embryo
3. Pollen grains are preserved as fossils because of presence of –
4. Penetration of the sperm in the ovum is followed by-
a) formation of first polar body
b) comletion of meiosis II✓
c) first meiosis
d) dissolution of zona pellucid
5. How many type of gametes would be produced if the genotype of a parent is AaBB?
b) 2 ✓
6. Which of the following amino acid substitution is responsible for causing sickle cell anemia ?
a) Valine is substituted by Glutamic acid in alfa globin chain at sixth position
b) Valine is substituted by Glutamic acid in beta globin chain at 7th position
c) Glutamic acid is substituted by Valine in situs judi slot globin chain at sixth position
d) Glutamic acid is replaced by valine in beta globin chain at sixth position. ✓
7. Which of the following combination of chromosomes numbers represents the correct sex determination pattern in honey bees?
a) male 32, female 16
b) male 16, female 32 ✓
c) male 31 , female 32
d) female 31 ,male 30
8. 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 the operator.
9. At what stage of life is oogenesis initiated in human female ?
a) at puberty
b) during menarch
c) during menopause
d) during embryonic development✓
10. The spermatogonia divides by-
a) meiotic division
b) mitosis division✓
c) both mitotic and meiotic division
d) none of the above
11. Family planning programme in India was initiated in-
12. Ovulation does not occure in lactating mother because of the release of-
13. The allels which appear in the first filial generation are called-
c) dominant ✓
14. What will be the phenotypic features in first filial situs judi slot generation after a cross between a homozygous female and a heterozygous male for a single character-
c) 1:1 ✓
d) none of these
15. A couple has 5 daughters. What is the possibility of their having a son next time?
a) 50% ✓
16. If one parent belongs to A blood group and the other to O blood group,their children possibly represent-
a) A and B groups
b) AB only
c) A and O groups✓
d) All four groups
17. A nucleoside differs from a nucleotide due to the lack of :
c) phosphate group ✓
d) hydroxyl group
18. If a double stranded DNA has 20% cytosine, what be the percentage of adenine in it?
c) 30% ✓
19. Pyrimidines are :
b) monocyclic ✓
20. During translation, activated amino acids get linked to tRNA .This process is commonly known as :
a) charging of tRNA
b) charging of mRNA
c) aminoacylation of tRNA
d) Both a and b ✓
21. Densely packed and transcriptionally inactive part of chromatin is:
b) heterochromatin ✓
d) solenoid fibre
22. In the given diagram, identify A,B and C.
a) A –DNA, B-H1 histone,C-Histone octamer ✓
b) A-RNA, B-cistron, c-DNA
c) A-DNA,B-H3 histone, C-Histone tetramer
d) A-DNA, B-H1 histone, C-Histone octamer
Section –B (Attempt any 15)
23. In a fertilized ovule n, 2n and 3n conditions occur respectively in-
a) zygote, nucellus and endosperm
b) endosperm, nucellus and zygote
c) antipodals, zygote and endosperm ✓
d) synergids, antipodals and integuments
24. A woman undergoing IVF treatment has blocked fallopian tubes. The technique by which the embryo with more than 8 blastomeres will be transferred into the woman for further development is:
c) IUT ✓
25. The mode of action of the Copper ions of Cu-T an IUD is to-
a) make the uterus unsuitable for implantation
b) decrease the movement of sperms✓
c) increase the movement of sperms
d) make the cervix hostile to the sperms
26. To produce 400 seeds ,the number of meiotic divisions required will be:
27. In Snapdragon ,RR is phenotypically red flowers, rr is white and Rr is pink. Select the phenotypic ratio in F1 generation when a cross is performed between RR and Rr:
a) 1 red:2 pink: 1white
b) 2-pink :1 white
c) 2 red : 2pink ✓
d) all pink
28. Which structure in the ovary will remain functional after implantation of pre-embryo in uterus?
a) tertiary follicle
b) corpus luteum ✓
c) primary follicle
d) grafian follicle
29. Which cellular process shown below occurs in nucleus?
a) DNA replication ✓
30. The thalamus contributes to the fruit formation in-
31. RNA is the genetic material in:
c) Tobacco Mosaic Virus (TMV) ✓
32. Spiny and sticky pollen grains and attractively coloured flowers are associated with:
b) entomophily ✓
33. Which hormone induces the rupture of mature graafian follicle?
b) Gn RH
34. The function of labeled part X is:
35. Mendelian disorders can be detected by_________.
d) pedigree analysis✓
36. A girl is colourblind.What type of her parents would be?
a) mother is carrier, fatheris normal
b) mother is carrier, father is colourblind✓
c) father is colourblind , mother is normal
d) mother is colourblind ,father is normal
37. Which of the following diseases cannot be diagnosed by amniocentesis?
a) Down s syndrome
b) Sickle cell disease
c) Jaundice ✓
d) Cystic fibrosis
38. Abortion can be safely done about weeks of pregnancy:
b) 12 ✓
c) 8 -10
d) 15 – 18
39. The Law of Segregation is also called Law of_________.
b) Purity of gametes ✓
c) Punnet hypothesis
d) Independent assortment
40. The double helix structure of DNA was proposed by:
b) Watson and Crick ✓
d) Hershey and chase
Section—C (Attempt any 5 questions)
Question No. 41 to 45have two statements—Assertion (A) and Reason (R) .Answer these questions selecting the correct option given below-
Tick A if both A and R are true and R is crrect explanation of A.
Tick B if both A and R are true and R is not correct explanation of A.
Tick C if A is true but R is false.
Tick D if A is false but R is true.
41. Assertion:-Lactational amenorrhea is the natural method of contraception.
Reason: It increases the killing of sperms.
42. Assertion: Saheli ,an oral contraceptive pills for females ,contains a steroid.
Reason : It is a once a week pill with very few side effects.
43. Assertion: Adenine cannot pair with cytosine.
Reason: Adenine and cytosine do not have complementarity between their respective hydrogen donor and hydrogen acceptor sites.
44. Assertion: The genetic code is degenerate.
Reason: For a particular amino acid more than one codon can be used.
45. Assertion: Turner s syndrome is caused due to absence of the X and Y sex chromosome.
Reason: Such individuals show masculine as well as feminine development.
46. Assertion: Overpopulation has become a serious problem in developing countries.
Reason: It leads to exhaustion of natural situs judi slot online terpercaya 2022 mudah menang resources causes unemployment and increases pollution.
47. Assertion: In human male, testes are extra abdominal lie in scrotal sacs.
Reason: Scrotum keeps testicular temperature lower than inner region for normal spermatogenesis.