Chapter8/9 Bio SAC

Q: Why is genetic diversity important?

A: It helps a species survive changes in the environment.

Why: More variation = more chances to survive

Q: How does genetic diversity increase?

A: Through genetic mutations creating new alleles.

Why: Mutations add new versions of genes.

what are alleles?

different versions or forms of a gene

Q: What happens to organisms without helpful variations?

A: They may become extinct if the environment changes.

Why: They can’t compete or cope.

Q: What does having many alleles in a population do?

A: It increases genetic diversity and survival chances.

Why: Wider gene pool = higher resilience.

Q: What are structural adaptations?

A: Physical features that help survival (e.g., thick fur).

Q: What are physiological adaptations?

A: chemical Body functions that help survival (e.g., venom production).

Q: What are behavioural adaptations?

A: Actions or habits that help survival (e.g., migration).

Q: What types of species relationships affect populations?

A: Competition, predator-prey, parasitism, symbiosis.
Why: Interactions change birth, death, and resources.

what is competition on a population?

competing for the same limited resources

what is a predator-prey relationship?

one species hunts and kills another species for food

what is parasitism?

one benefits, the other is harmed

what is mutualism?

both organisms benefit

what is commensalism?

one benefits, the other is neither benefited or harmed

what is symbiosis?

close biological interaction between two different species

Q: How do these relationships ( Competition, predator-prey, parasitism, symbiosis, etc) affect populations?

A: They change the population’s size and where it lives.
Why: They shift survival and distribution.

Q: What is a keystone species?

A: A species that greatly affects other organisms and the ecosystem.
Why: Remove it, and the system changes drastically.

Q: What do food chains and webs show?

A: How energy flows through trophic levels.

1. producer

2. primary consumer

3. secondary consumer

4. tertiary consumer

5. decomposers

Q: What are advantages of asexual reproduction?

A: Fast reproduction, no mate needed, usually a lot of offspring at once

Q: What are disadvantages of asexual reproduction?

A: Low genetic diversity, less adaptability.

Why: All alike = one threat can wipe many.

Q: How does sexual reproduction increase diversity?

A: By mixing genes from two parents through fertilisation.

Q: What are advantages of sexual reproduction?

A: More genetic variation, better survival.
Why: Variation helps adapt to change.

Q: What are disadvantages of sexual reproduction?

A: Slower and needs a mate.
Why: Costs time/energy and risk.

Q: What is internal reproduction?

A: Fertilisation happens inside the body.
Why: Protects gametes/embryos.

Q: What is external reproduction?

A: Fertilisation happens outside the body (e.g., in water).
Why: Many gametes, less protection.

Q: What is embryo splitting?

A: A cloning method where an embryo is split to make identical individuals.
Why: Early cells become separate but identical embryos.

Q: What are cloning advantages?

A: Makes many identical animals quickly, preserves traits.
Why: Guarantees desired genetics.

Q: What are cloning disadvantages?

A: Health risks and ethical issues.
Why: High failure rates and welfare concerns.

Q: What abiotic factors affect populations?

A: Non-living things like temperature and water.
Why: Set the physical limits for life.

Q: What biotic factors affect populations?

A: Living things like predators and competitors.
Why: Influence survival and reproduction.

Q: How do humans affect species survival?

A: Positively or negatively, by changing environments or protecting species.
Why: Habitat loss vs. conservation actions.

Q: What is important for large-scale research?

A: Planning and resources to make it practical.
Why: Ensures valid, workable studies.