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

71.

Factor govering the earth surface is

  • Topographic

  • Edaphic

  • Temperature

  • Biotic


A.

Topographic

Topographical conditions responsible for the soil profile within a given climatic region.


72.

Bacterial endotoxin is

  • A toxic protein that stays inside the bacterial cell

  • A toxic protein that is excreted into the medium

  • Lipopolysaccharide located on the surface of the bacteria

  • None of the above


C.

Lipopolysaccharide located on the surface of the bacteria

Lipopolysaccharide present on the cell wall of bacteria acts as endotoxin.


73.

Biological treatment of water pollution is done with the help of

  • Fungi

  • Lichen

  • Phytoplanktons

  • None of the above


C.

Phytoplanktons

Water hyacinth (Phytoplanktons) can clean polluted water. Hyacinth has great potential to accumulate poisonous metals and a radioactive substance.


74.

In DNA, when AGCT occurs, their association is as per which of the following pair

  • A-G, C-T

  • A-T, G-C

  • A-C, G-T, A-C, E-T

  • All of these


B.

A-T, G-C

DNA molecule has four bases-adenine guanine-cytosine and thymine. Adenine always pairs with thymine and guanine pairs with cytosine. Their association of A-T and G-C.


75.

A segment of DNA has 120 adenine and 120 cytosine bases. The total number of nucleotides present in the segment is

  • 60

  • 240

  • 120

  • 480


D.

480

According to Charagff's rules, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine.

A = T(120)
G = C(120)

The total number of nucleotides would be 120 x 4 = 480


76.

If the Bengal tiger become extinct

  • Hyenas and wolves will become scarce

  • Its gene pool will be lost forever

  • The wild areas will be safe for man and domestic

  • The population of beautiful animals like deer will get stabilised


B.

Its gene pool will be lost forever

Gene pool is collective name for all the genes of particular population. 


77.

Agar-Agar is produced by

  • Fungi

  • Alage

  • Bacteria

  • Blue-green algae


B.

Alage

Agar-Agar is obtained from members of Rhodophyceae algae collectively called agarophytes. These include Gelidium Gracillaria etc.


78.

Endosperm of gymnosperms is

  • Haploid

  • Tetraploid

  • Diploid

  • None of these


A.

Haploid

The endosperm of a gymnosperm is a pre-fertilisation tissue. It is basically the female gametophyte hence it is haploid unlike triploid in angiosperm.


79.

Pebrine is a disease of

  • Fish

  • Honey Bee

  • Silk Worm

  • lac insect


C.

Silk Worm

Pepbrine is a disease of silkworm caused by a small parasite. Nosema, which has a devastating effect on the silk industry.


80.

The direction of energy flow is

  •  Producers → Herbivores → Decomposers → Omnivores

  • Producers → Carnivore → Herbivores → Decomposes

  • Decomposers → Carnivores → Herbivores → Producers

  • Producers → Herbivores → Carnivores → Decomposers


D.

Producers → Herbivores → Carnivores → Decomposers