Biology 20Q

What is sexual reproduction?

The process involving two parents whose genes fuse to produce a genetically different cell.

What is asexual reproduction?

The process in which one parent cell produces genetically identical cells.

What are the gametes in animals?

The sex cells, specifically sperm and egg.

What type of cell division produces gametes?

Meiosis, which results in the production of genetically different cells.

How many chromosomes are found in human body cells?

46 chromosomes.

How many chromosomes are found in human gametes?

23 chromosomes.

What is a clone?

An organism or cell produced asexually from one parent that is genetically identical to that parent.

What does variation mean?

The differences in characteristics between individuals of the same species.

What can cause variation?

Genetics and/or environmental factors.

What is a species?

A group of individuals in a population that are able to breed and produce fertile offspring.

Who proposed the theory of natural selection?

Charles Darwin and Alfred Russel Wallace.

Why was Darwin's theory of natural selection discredited?

It lacked evidence, did not account for DNA as a molecule of inheritance, and conflicted with beliefs about creation.

What does genetic screening involve?

Testing people for the presence of a particular allele or other genetic abnormalities.

What is selective breeding?

The deliberate breeding of organisms to enhance desirable traits in their offspring.

What are potential problems with selective breeding?

Future generations may share similar genes, increasing the risk of genetic diseases and limiting the production of new varieties.

Give an example of selective breeding.

Breeding cows to produce more meat or milk, or breeding chickens for larger eggs.

What is natural selection?

The process by which a species evolves over time due to environmental changes or competition.

How does natural selection cause a useful gene to increase in a species?

Useful alleles provide survival advantages, allowing those individuals to reproduce and pass on the advantageous traits.

What is a mutation?

A random change to genetic material.

Why can natural selection be more easily shown in bacteria?

Bacteria divide and pass on genes quickly.

What is extinction?

The state when no remaining individuals of a species are alive.

How can the likelihood of antibiotic resistance in bacteria be reduced?

By using antibiotics sparingly and ensuring prescribed courses are completed.