Biology

Question 1

A species is a…

Answer 1

group of organisms that
are able to reproduce to give offspring
that are also able to reproduce.

Question 2

Members of the same species have…

Answer 2

very similar characteristics (features).
However, there is variation in these
characteristics.

Question 3

What are some characteristics due to?

Answer 3

environmental factors

Question 4

Inherited variation:

Answer 4

Offspring inherit characteristics from their parents and these characteristics can vary
(e.g. brown eyes and blue eyes). This is inherited variation.

Question 5

Chromosomes, genes and DNA

Answer 5

An organism’s characteristics are controlled by genetic information contained in a code in DNA.
James Watson and Francis Crick discovered the structure of DNA by making use of the data of
other scientists, such as Rosalind Franklin and Maurice Wilkins.

Question 6

Chromosomes, genes, and DNA

Answer 6

An organism’s characteristics are controlled by genetic information contained in a code in DNA.
James Watson and Francis Crick discovered the structure of DNA by making use of the data of
other scientists, such as Rosalind Franklin and Maurice Wilkins.

Question 7

How many different types of chromosomes in humans?

Answer 7

23

Question 8

Inheritance probabilities:

Answer 8

For some characteristics, scientists can work
out the probability that a child will inherit that
characteristic. Probabilities are shown as
percentages, decimals or fractions.

Question 9

Adaptation:

Answer 9

Animals and plants are adapted to where they
live; they have characteristics that allow them
to survive in that habitat.

Question 10

How are Jack rabbits adapted to live in desert habitats?

Answer 10

• large ears to allow heat to escape and for good hearing.
• does not drink, gets all the water from its food.
• large hind legs to run fast and prevent animals from eating it.

Question 11

Natural selection:

Answer 11

is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success.

Question 12

Who came up with the idea of evolution?

Answer 12

Charles Darwin and Alfred Russel Wallace

Question 13

Endangerment and extinction

Answer 13

Changes in an ecosystem can cause species to become endangered or extinct.

Question 14

Cause of endangerment and extinction:

Answer 14

● changes in physical environmental factors
● competition from other organisms
● disease
● human activities (e.g. hunting, clearing habitats, using poisons).