Variation And Adaptation

Question 1

What are the differences between histogram and bar charts?

Answer 1

A bar chart has categories
A histogram has a number range
A bar chart has gaps

Question 2

What is continuous variation?

Answer 2

Occurs when all individuals can be divided over a range, e.g. weight

Question 3

What is discontinuous variation?

Answer 3

Occurs when all individuals can be divided into distinct groups, e.g. tongue - rolling

Question 4

What sources does variation come from?

Answer 4

Genetic

Environmental

Question 5

What factors influence height?

Answer 5

Both genetic and environmental factors influence height, e.g. genes from parents, but balanced diet needed

Question 6

Why do offspring show variation?

Answer 6

Because two sets of genes join together, one from each parent

Question 7

Natural selection states…

Answer 7

That there is always variation in the phenotypes, and this can be seen in bacteria

Question 8

What is the definition of survival of the fittest?

Answer 8

When bacteria are treated with an antibiotic, such as penicillin, most of them are killed, however, a small number (the fittest) survive.
They have an allele caused by a mutation that gives them antibiotic resistance.
Very soon only the resistant bacteria remain, therefore they are the only ones surviving to pass on their advantageous mutation to their offspring and all the offspring in the next generation will be resistant to antibiotics.

Question 9

State the theory of natural selection by Charles Darwin:

Answer 9

There is a constant struggle for existence.
the better adapted individuals survive this struggle/competition. This leads to differential survival, and therefore, survival of the fittest.
The best adapted individuals are more likely to survive and reproduce. Consequently, they will be the ones that are more likely to pass on their genes to the next generation.
Failure to adapt to the environment may result in extinction of the species over time.

Question 10

State Darwin’s theory of evolution:

Answer 10

This is a continuing process of natural selection; it leads to gradual changes in organisms over time. This may result in the formation of a new species.

Question 11

What are fossils?

Answer 11

The remains of dead plants and animals from millions of years ago that, due to high temperatures and pressure, have been preserved in rock.