[Sem 2] Biology Evolution

Question 1

Genetic Diversity

Answer 1

The range of genetic differences within a species.

Question 2

Importance of Genetic Diversity

Answer 2

Allows adaptation to environmental changes, increasing survival chances​.

Question 3

Causes of Genetic Diversity

Answer 3

Mutations, sexual reproduction, and gene flow between populations​.

Question 4

Consequences of Low Genetic Diversity

Answer 4

Reduces adaptability and increases extinction risk when faced with environmental changes.

Question 5

Darwin’s Theory of Natural Selection

Answer 5

Process where organisms better suited to their environment survive and reproduce.

Question 6

Natural Selection Steps

Answer 6

1. Variation exists within a population.
2. Selection pressures favour certain traits.
3. Organisms with advantageous traits survive and reproduce.
4. Over generations, beneficial traits become more common​

Question 7

Selection Pressure

Answer 7

Environmental factors that affect an organism’s survival and reproduction, e.g. predators, climate​.

Question 8

Lamarck’s Theory of Inheritance of Acquired Characteristics

Answer 8

Traits developed during an organism’s life (like muscle strength) are passed to offspring. Currently disproven.

Question 9

Physiological Adaptation

Answer 9

Internal functions aiding survival (e.g. camels conserving water).

Question 10

Structural Adaptation

Answer 10

Physical traits aiding survival (e.g. thick fur in arctic animals).

Question 11

Behavioural Adaptation

Answer 11

Actions improving survival (e.g. birds migrating)​.

Question 12

Genetic Drift

Answer 12

Random changes in allele frequencies, more impactful in small populations. E.g. natural disasters, habitat loss

Question 13

Bottleneck Effect

Answer 13

Sharp reduction in population size due to an event (e.g., earthquake).

Question 14

Impact of Bottleneck Effect

Answer 14

Loss of genetic diversity, leaving a population vulnerable to future changes​.

Question 15

Convergent Evolution

Answer 15

Unrelated species evolve similar traits due to similar environmental pressures. E.g. wings in both birds and insects.

Question 16

Divergent Evolution

Answer 16

Related species evolve different traits due to different environmental pressures. E.g. Darwin’s finches developing different beaks.

Question 17

Primates Characteristics

Answer 17

Opposable thumbs, binocular vision, large brains (e.g., monkeys, apes)​.

Question 18

Hominoids Characteristics

Answer 18

Larger body size, no tail, complex brain (e.g., gorillas, chimpanzees)​.

Question 19

Hominins Characteristics

Answer 19

Bipedalism, advanced tool use, smaller canine teeth (e.g., humans, ancestors of humans)​.

Question 20

Classification Levels

Answer 20

Kingdom → Phylum → Class → Order → Family → Genus → Species
(Largest to smallest group; each step adds more specific traits)​.

Question 21

Biodiversity

Answer 21

Variety of life on Earth at genetic, species, and ecosystem levels. Supports ecosystems, adapts to changes, and enhances survival.

Question 22

Adaptive Evolution

Answer 22

Evolution that increases fitness in a specific environment​.

Question 23

Adaptive Radiation

Answer 23

Rapid evolution of many species from a common ancestor in diverse environments.

Question 24

Mutation

Answer 24

Change in DNA that can lead to variation and sometimes new traits.

Question 25

Speciation

Answer 25

Formation of new species due to evolutionary changes. A new species when it’s not possible to mate with different species.