Subject

Biology

Class

NEET Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

 Multiple Choice QuestionsMultiple Choice Questions

41.

The number of hydrogen bonds between adenine and thymine in a DNA molecule is :

  • two

  • three

  • four

  • eight


A.

two

There are two hydrogen bonds present between Adenine(A) and Thymine (T) whereas there are three hydrogen bonds between Cytosine (C) and Guanine (G).


42.

A eukaryotic gene contains two kinds of base sequences. Which of these plays an important role in protein synthesis?

  • Introns

  • Exons

  • Both 'a' and 'b'

  • None of the above


B.

Exons

In eukaryotic genes some non-coding parts are interspersed between coding parts. These, non coding parts are called introns and coding sequence are known as exons. Exons play significant role in protein synthesis.


43.

Cook cambium and vascular cambium are :

  • parts of secondary xylem and phloem

  • parts of pericycle

  • lateral meristems

  • apical meristems


C.

lateral meristems

Cork cambium and vascular cambium are lateral meristems and responsible for growth in thickness.


44.

Major role of minor elements inside living organisms is to act as :

  • binder of cell structure

  • constituent of hormone

  • building blocks of important amino acids

  • cofactor of enzymes


D.

cofactor of enzymes

The micro-elements are required by plants in trace ammount (0.1 mg/gm dry matter). These are mostaly involved in the functioning of enzyme as co factors or metal activator.


45.

First natural cytokinin was discovered by :

  • Skoog and Miller

  • Letham

  • Benson and Calvin

  • Thimann and Went


B.

Letham

First natural cytokinin was obtained from unripe maize grains or Kernels. It is known as zeatin or 6- hydroxy 3- methyl trans butenyl amino purine.


46.

Which of the following is not vestigial in man ?

  • Tail vertebrae

  • Nails

  • Nictitating membrane

  • Vermiform appendix


B.

Nails

Vestigial organs are the organs which have lost its function and are imperfectly developed due to evolutionary changes. Eg, Nictitating membrane, tail vertebrae, vermiform appendix.


47.

The chemical used in National Malaria Eradication Programme is :

  • 2,4- D

  • BHC

  • DDT

  • Pyrethroid


C.

DDT

DDT or Dichloro Diphenyl trichloroethane was synthesized by a German student and was later rediscovered by Dr. Paul Muller. It was used in National Malaria Eradication Programme to kill malaria mosquitoe Anopheles.


48.

Male cone of Pinus possesses :

  • mega sporophylls

  • microsporophylls

  • anthers

  • ligules


B.

microsporophylls

The male cone of Pinus has a central axis and a number of spirally arranged mirosporophylls. Each microsporophylls bears two oblong microsporangia abaxially on the proximal part.


49.

Epipetalous and syngenesious stamens occur in

  • Solanaceae

  • Brassicaceae

  • Fabaceae

  • Asteraceae


D.

Asteraceae

Epipetalous (stamen borne on the petal) and syngenesious (anthers united laterally into a tube) stamens are found in family Asteraceas.


50.

C4 plants, synthesis of sugars/final CO2 fixation occurs in:

  • palisade cells

  • spongy cells

  • undifferentiated mesophyll cells

  • bundle sheath cells


D.

bundle sheath cells

In C4 plants, CO2 fixation occurs inside the bundle sheath cell through calvin cycle. RuBP of calvin cycle is called secondary or final acceptor of CO2 in C4 plants.