Explore topic-wise MCQs in Graduate Aptitude Test (GATE).

This section includes 100 Mcqs, each offering curated multiple-choice questions to sharpen your Graduate Aptitude Test (GATE) knowledge and support exam preparation. Choose a topic below to get started.

1.

Most hazardous metal pollutant of automobile exhausts is

A. mercury
B. cadmium
C. lead
D. copper
Answer» D. copper
2.

 Food chain in which microorganisms breakdown the food formed by primary producersis

 

A. parasitic food chain
B. detritus food chain
C. consumer food chain
D. predator food chain
Answer» C. consumer food chain
3.

Which one is true?

A. commensalism when none of the interacting populations affect each other
B. symbiosis when the interaction is useful to both the populations
C. symbiosis when neither populations affects each other
D. commensalism when the interaction is useful to both the populations
Answer» C. symbiosis when neither populations affects each other
4.

 Deep black soil is productive due to high proportion of 

A. sand and zinc
B. gravel and calcium
C. clay and humus
D. silt and earthworm
Answer» D. silt and earthworm
5.

Domestic waste constitutes

A. nonbiodegradable pollution
B. biodegradable pollution
C. effluents
D. air pollution
Answer» B. biodegradable pollution
6.

Pyramid of numbers in a grassland/tree ecosystem

A. always inverted
B. always upright
C. both (a) and (b)
D. spindle-shaped.
Answer» C. both (a) and (b)
7.

Deforestation will decrease

 

A. soil erosion
B. soil fertility
C. land slides
D. rainfall.
Answer» E.
8.

 Major aerosol pollutant in jet plane emission is

A. sulphur dioxide
B. carbon monoxide
C. methane
D. fluorocarbon
Answer» E.
9.

The relation between algae and fungi in lichen is

A. symbiosis
B. parasitism
C. commenalism
D. protocooperation
Answer» B. parasitism
10.

Soil conservation is

A. conversion of sterile soil into fertile one
B. aeration of soil
C. erosion of soil
D. protection against loss.
Answer» E.
11.

Green house effect is warming due to

A. infra-red rays reaching earth
B. moisture layer in atmosphere
C. increase in temperature due to increase in carbon dioxide concentration of atmosphere
D. ozone layer of atmosphere
Answer» D. ozone layer of atmosphere
12.

 in an ecosystem, which one shows one-way passage

A. free energy
B. carbon
C. nitrogen
D. potassium
Answer» B. carbon
13.

What is true of ecosystem?

A. primary consumers are least dependent upon producers
B. primary consumers out-number producers
C. producers are more than primary consumers
D. secondary consumers are the largest and most powerful
Answer» D. secondary consumers are the largest and most powerful
14.

Which organisms externally digest dead organic matter and then absorb the nutrients?

A. saprotrophs
B. autotrophs
C. heterotrophs
D. detritivores
Answer» B. autotrophs
15.

What term refers to a community and its abiotic environment?

A. biosphere
B. ecosystem
C. habitat
D. niche
Answer» C. habitat
16.

Which process has the GREATEST effect in determining which members of a population are most likely to survive until reproductive age?

A. natural selection
B. evolution
C. hybridization
D. meiosis
Answer» B. evolution
17.

According to Darwin's theory of evolution, what causes the struggle for survival in populations?

A. Overproduction of offspring
B. Natural selection
C. Favorable heritable variations
D. Competition between the fittest individuals in the population
Answer» B. Natural selection
18.

Why has evolution resulted in antibiotic resistance in bacteria?

A. Bacteria have learnt how to neutralize effects of antibiotics and pass that onto their offsprings
B. Bacteria change their metabolism to cope with the presence of antibiotics.
C. Bacteria resistant to the antibiotic survive to pass on this characteristic to their offspring.
D. Not completing a course of antibiotics allows resistant bacteria to develop.
Answer» D. Not completing a course of antibiotics allows resistant bacteria to develop.
19.

What is natural selection?

A. The mechanism that leads to increasing variation within a population.
B. The cumulative change in the heritable characteristics of a population.
C. The mechanism that increases the chance of certain individuals reproducing.
D. The mechanism that explains why populations produce more offspring than the environment can support.
Answer» D. The mechanism that explains why populations produce more offspring than the environment can support.
20.

Classification in biology involves putting organisms that share characteristics together in groups. In which type of group do the organisms share the MOST characteristics?

A. Genus
B. Class
C. Family
D. Order
Answer» B. Class
21.

The scientific names of two organisms are "Lathyrus palustris" and "Angelica palustris". What is the relationship between these organisms?

A. They are both different species and different genera
B. They both belong to the same genus but they are different species
C. They both belong to the same species but different genera
D. They both belong to the same species and the same genus
Answer» B. They both belong to the same genus but they are different species
22.

What statement can be made about members of the same order?

A. They can all interbreed successfully.
B. They all belong to the same family
C. They all belong to the same genus
D. They all belong to the same class
Answer» E.
23.

All are the characteristics of reptilia except

A. Amniotic eggs.
B. Cutaneous respiration
C. Dry skin.
D. Scales.
Answer» C. Dry skin.
24.

Sponges posses flagellum in

A. Amoebocytes.
B. Choanocytes.
C. Epithelial cells.
D. All of the above.
Answer» C. Epithelial cells.
25.

In Platyhelminthes, the main function of the flame cell is

A. Reproduction
B. Excretion.
C. Osmoregulation.
D. None of the above.
Answer» C. Osmoregulation.
26.

The photoreceptor which is common in the regulation of biological clock in plants, molds, and flies

A. Cryptochrome.
B. Phytochrome.
C. carotenoid.
D. All of the above.
Answer» B. Phytochrome.
27.

Which of the following mating system is common in mammals

A. Polygamy.
B. Polyandry.
C. Polygyny.
D. Monogamy.
Answer» D. Monogamy.
28.

Which of the following gymnosperm have similar vascular tissue system

A. Conifers.
B. Gnetophytes.
C. Cycads.
D. None of the above.
Answer» C. Cycads.
29.

The first events in the evolution of eukaryotic

A. Chloroplast and endosymbiosis evolution.
B. Mitochondria and endosymbiosis
C. Compartmentalisation and nucleus formation.
D. None of the above.
Answer» D. None of the above.
30.

In which of the following taxonomic group contain species that have similar characteristics as a result of convergent evolution?

A. Polyphyletic
B. Monophyletic
C. Cladistic
D. None of the above.
Answer» B. Monophyletic
31.

Which of the following do not contribute to the genomic diversity among various species

A. Gene duplication.
B. Lateral gene transfer.
C. Gene transcription.
D. Chromosomal mutation.
Answer» D. Chromosomal mutation.
32.

Which of the following is not the character of arthropods

A. Closed circulatory system.
B. Jointed appendages.
C. Segmented ganglia.
D. External segmentation.
Answer» B. Jointed appendages.
33.

Which of the following phylum is closely related to the Phylum Chordata?

A. Echinodermata.
B. Mollusca.
C. Platyhelminthes.
D. All of the above.
Answer» B. Mollusca.
34.

Which of the following is used to define the behavior that occurs as a result of experience?

A. Imprinting.
B. Habituation.
C. Misperception.
D. All of the above.
Answer» D. All of the above.
35.

High parental care in animal is associated with the

A. Iteroparity.
B. Large number of offspring.
C. Semelparity.
D. Large size of offspring.
Answer» B. Large number of offspring.
36.

When unrelated group of organism develops similar adaptive phenotype called adaptive convergence. This leads to the

A. Change in gene frequency.
B. Territoriality.
C. Parallel evolution
D. Formation of homologous structure
Answer» D. Formation of homologous structure
37.

DNA sequence analysis suggests that the eukaryotic mitochondrial DNA originated from the

A. Algae.
B. Fungi.
C. Protista.
D. Bacteria.
Answer» E.
38.

Which of the following is called the age of reptilian

A. Permian period.
B. Cenozoic era.
C. Mesozoic era.
D. None of the above.
Answer» D. None of the above.
39.

Two species live in the same geographical area but reproduce at the different time is known as

A. Reproductive isolation.
B. Mechanical isolation.
C. Temporal isolation.
D. Behavioral isolation.
Answer» D. Behavioral isolation.
40.

eathers of birds is a modified form of reptilian scale.This modification of reptilian scale to feathers of birds is the example of

A. Allometric growth
B. Preadaptation
C. Hybrid breakdown
D. Paedomorphogenesis
Answer» C. Hybrid breakdown
41.

Brassica juncea can be used as the phytoremediation agent for the removal of ___________ from the soil.

A. Nickel
B. Cadmium
C. Lead
D. Arsenic
Answer» D. Arsenic
42.

Which of the following is a micronutrient in plants?

A. Ca
B. Mg
C. Mn
D. S
Answer» D. S
43.

In an ecological interaction, the commensalism can be represented as:

A. + –
B. – +
C. + 0
D. – 0
Answer» D. – 0
44.

Which of the following is an example for link species?

A. Clownfish
B. Cuscuta
C. Mycorrhiza
D. Lichen
Answer» D. Lichen
45.

A species in Tropical Rainforest which acts as a Key-stone species:

A. Dalbergia
B. Ficus
C. Santalum
D. Nepenthes
Answer» C. Santalum
46.

Two biodiversity hot-spots in India are

A. Eastern Himalayas and Western Ghats
B. Western Himalayas and Western Ghats
C. Eastern Himalayas and Eastern Ghats
D. Western Himalayas and Eastern Ghats
Answer» B. Western Himalayas and Western Ghats
47.

The ratio between regional and local species diversity is measured as:

A. Alpha diversity
B. Beta diversity
C. Gamma diversity
D. Delta diversity
Answer» C. Gamma diversity
48.

Methemoglobinemia is caused by the drinking of water contaminated with:

A. Phosphate
B. Mercury
C. Cadmium
D. Nitrate
Answer» E.
49.

Pneumatophores are characteristic of:

A. Alpine plants
B. Mangrove plants
C. Desert plants
D. Aquatic plants
Answer» C. Desert plants
50.

Which of the following is NOT an adaptation of xerophytic plants?

A. The presence of palisade like tissue in stem
B. The presence of thick cuticle
C. CAM cycle for photosynthesis
D. Large leaves if present
Answer» E.