Term 1 Sample Paper Class 12 Biology 2021-22

Term 1 Sample Paper Class 12 Biology 2021-22

 

Time: 1.30 hour

Maximum marks-35

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.

a) Stamen

b) Filament                       

c) Pollen grain

d) Androecium

 

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 –

a) cellulose

b) sporopollenin             

c) pectocellulose

d) lignin

 

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?

a) 1

b) 2                          

c) 3

d) 4

 

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 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-

a) 1920

b) 1930                 

c) 1950

d) 1951

 

12. Ovulation does not occure in lactating mother because of the release of-

a) inhibin

b) prolactin                

c) prostaglandins

d) oxytocin

 

13. The allels which appear in the first filial generation are called-

a) holandric 

b) recessive                      

c) dominant  

d) lethal

 

14. What will be the phenotypic features in first filial generation after a cross between a homozygous female and a heterozygous male for a single character-

a) 3:1 

b) 1:2:1                   

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%

b) 100%                      

c) 25%

d) 40%

 

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 :

a) base

b) sugar                                

c) phosphate group

d) hydroxyl group

 

18. If a double stranded DNA has 20% cytosine, what be the percentage of adenine in it?

a) 20%

b) 40%                    

c) 30%

d) 60%

 

19. Pyrimidines are :

a) dicyclic   

b) monocyclic                    

c) tricyclic

d) tetracyclic

 

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:

a) euchromatin 

b) heterochromatin                     

c) NHC 

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:

a) ZIFT 

b) GIFT                                  

c) IUT  

d) AI

 

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:

a) 800    

b) 1600                   

c) 400 

d) 200

 

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               

b) Translation—Initiation            

c) Translation—Elongation   

d) Translation—termination

 

30. The thalamus contributes to the fruit formation in-

a) tomato           

b) apple                             

c) orange                             

d) mango

 

31. RNA is the genetic material in:

a) prokaryotes    

b) eukaryotes                     

c) Tobacco Mosaic Virus (TMV)

d) amoeba

 

32. Spiny and sticky pollen grains and attractively coloured flowers are associated with:

a) hydrophily                     

b) entomophily                   

c) ornithophily                    

d) anaemophily

 

33. Which hormone induces the rupture of mature graafian follicle?

a) FSH                                 

b) Gn RH                          

c) progesterone                    

d) LH

 

34. The function of labeled part X is:

a) dehiscence  

b) mechanical                           

c) protection    

d) nutrition

 

35. Mendelian disorders can be detected by_________.

a) idiogram   

b) karyotype                      

c) amniocentesis                       

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:

a) 4                                         

b) 12                              

c) 8 -10                                     

d) 15 – 18

 

39. The Law of Segregation is also called Law of_________.

a) Probability                                 

b) Purity of gametes                     

c) Punnet hypothesis                   

d) Independent assortment

 

40. The double helix structure of DNA was proposed by:

a) Griffith 

b) Watson and Crick                     

c) Chargaff                                 

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.

Answer: C

 

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.

Answer: D

 

43. Assertion: Adenine cannot pair with cytosine.

Reason: Adenine and cytosine do not have complementarity between their respective hydrogen donor and hydrogen acceptor sites.

Answer: A

 

44. Assertion: The genetic code is degenerate.

Reason: For a particular amino acid more than one codon can be used.

Answer: A

 

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.

Answer: D

 

46. Assertion: Overpopulation has become a serious problem in developing countries.

Reason: It leads to exhaustion of natural resources causes unemployment and increases pollution.

Answer: A

 

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.

Answer: A

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