Variation & Adaption

Question 1

What are the differences between histograms & bar charts?

Answer 1

Bar chart has categories
Histogram has number range
Bar chart has gaps

Question 2

What is continuous variation? Example?

Answer 2

When individuals are sorted over a range

Height

Question 3

What is discontinuous variation? Example?

Answer 3

Occurs when all individuals can be divided into distinct groups
Tongue rolling

Question 4

What sources do variation come from?

Answer 4

Genetic

Environmental

Question 5

What does natural selection state?

Answer 5

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

Question 6

How does natural selection effect bacteria?

Answer 6

There is always variation in bacteria.
When bacteria are treated with antibiotics such as penicillin, most of the are killed, however, a small number (the fittest) survive. This is natural selection.
They have an allele caused by a mutation which gives them antibiotic resistance.
Very soon, only the resistant bacteria remain, therefore they’re the only ones surviving to pass on their advantageous mutation to their offspring.
All the offspring in the next generation will be resistant to antibiotics

Question 7

Using the example of antibiotic resistance, discuss how variation and natural selection can lead to evolution or extinction

Answer 7

Bacteria there is variation.
The bacteria that aren’t resistant to antibiotics are killed.
The resistant bacteria will survive pass on their resistant allele

Question 8

What is Darwin’s theory of natural selection?

Answer 8

All living organisms produce more young than can survive
This leads to competition for resources, e.g. food and so there is a 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 more likely to pass on their genes to the next generation.
Failure to adapt to the environment may result in the extinction of a species.

Question 9

What is Darwin’s theory of evolution?

Answer 9

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 10

What are fossils?

Answer 10

The remains of dead plants and animals from millions of years ago that due to high temperatures and pressure have been preserved in rock. Fossils can provide solid evidence for evolution.

Question 11

If an organism reproduces sexually, then the offspring will show a lot of variation?. Why?

Answer 11

Because 2 sets of genes join together, one from each parent