Saturday, 23 October 2021

CBSE Class 12 Biology Term 1 MCQs (#class12Biology)(#biology)(#cbseterm1)(#biologymcqs)

CBSE Class 12 Biology Term 1 MCQs

CBSE Class 12 Biology Term 1 MCQs (#class12Biology)(#biology)(#cbseterm1)(#biologymcqs)


Q1: The outermost and innermost wall layers of microsporangium in an anther are respectively.

(a) Endothecium and tapetum

(b) Epidermis and endodermis

(c) Epidermis and middle layer

(d) Epidermis and tapetum



Q2: Which of the following fruit is a case of parthenogenesis?

(a) Fruit without seeds after pollination

(b) Fruit with seeds after pollination

(c) Fruit with viable seeds without fertilization 

(d) Fruit with viable seeds after fertilization.


Q3:  Entry of pollen tube through micropyle is called

(a) Mesogamy 

(b) Pseudogamy 

(c) Chalazogamy

(d) Porogamy



Q4: 'Corn cobs have long tassels'. This is because

(a) they are useful in protecting the pollen grains from wetting

(b) they can easily attract insects

(c) they can easily trap the air-borne pollen grains

(d) it helps them to reach the surface of the water which helps them to get pollinated by insects



Q5: The Leydig cells are a source of

(a) fructose 

(b) androgens

(c) progesterone 

(d) mucus



Q6: Oestrogen is more active during

(a) ovulatory phase 

(b) secretory phase

(c) menstrual phase 

(d) post-menstrual phase



Q7: Colostrum is important for newly born because

(a) it contains essential antigen

(b) it contains essential antibodies

(c) Both (a) and (b)

(d) it has more nutrients than ordinary milk



Q8: In oocyte secondary maturation occurs in

(a) ovary 

(b) abdominal cavity 

(c) Fallopian tube

(d) uterus



Q9: Which of the following is not a bacterial STD?

(a) Syphilis 

(b) Gonorrhea 

(c) Herpes genitalis 

(d) Chlamydiasi



Q10: Intensely lactating mothers generally do not conceive due to the

(a) suppression of gonadotropins

(b) hypersecretion of gonadotropins

(c) suppression of gametic transport

(d) suppression of fertilisation



Q11: The method of directly injecting sperm into the ovum is assisted by reproductive technology is called

(a) GIFT 

(b) ZIFT 

(c) ICSI 

(d) ET



Q12: Tubectomy is a method of sterilisation in which

(a) nucleus is removed 

(b) ovaries are removed

(c) a small part of the fallopian tube is removed 

(d) a small part of the vas deferens is removed



Q13: Distance between the genes and percentage of recombination shows

(a) a direct relationship 

(b) an inverse relationship

(c) a parallel relationship 

(d) no relationship



Q14: Downs syndrome is due to

(a) non-disjunction of chromosome 

(b) sex-linked inheritance

(c) crossing over 

(d) linkage



Q15: Who has given the concept of gene mapping?

(a) Thomas Hunt Morgan 

(b) Gregor John Mendel

(c) Alfred Sturtevant

(d) Henking



Q16: Mendels Law of independent assortment holds good for genes situated on the

(a) nonhomologous chromosomes 

(b) homologous chromosomes

(c) extranuclear genetic element 

(d) same chromosome



Q17: What is not the genetic code?

(a) It is nearly universal.

(b) It is degenerate.

(c) It is unambiguous.

(d) A codon in mRNA is read in a noncontiguous fashion.



Q18: Discontinuous synthesis of DNA occurs on one strand because

(a) DNA molecule being synthesized is very long

(b) DNA dependent polymerase catalyses polymerisation only in one direction (5-3‘) 

(c) It is a more efficient process

(d) DNA ligase has to have some role



Q19: Adenine pairs with thymine with

(a) 1 hydrogen bond 

(b) 2 hydrogen bond 

(c) 3 hydrogen bond 

(d) 4 hydrogen bond



Q20: The protein of DNA, which contains information for an entire polypeptide is called as

(a) Cistron 

(b) Muton

(c) Recon 

(d) Operon




Answers:

1: (d) Epidermis and tapetum

2: (a) Fruit without seeds after pollination

3: (d) Porogamy

4: (c) they can easily trap the air-borne pollen grains

5: (b) androgens

6: (b) secretory phase

7: (b) it contains essential antibodies

8: (c) Fallopian tube

9: (c) Herpes genitalis 

10: (a) suppression of gonadotropins

11: (c) ICSI 

12: (d) small part of vas deferens is removed

13: (a) a direct relationship 

14: (a) non-disjunction of chromosome 

15: (a) Thomas Hunt Morgan 

16: (b) homologous chromosomes

17: (d) A codon in mRNA is read in a noncontiguous fashion.

18: (b) DNA dependent polymerase catalyses polymerisation only in one direction (5-3‘) 

19: (b) 2 hydrogen bond 

20: (a) Cistron 


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