Variation and Types of Variation

Question 1

What is variation?

Answer 1

variation refers to the observable differences, some inherited (determined by genes) and some acquired (determined by environment) between individuals of the same species.

Question 2

What are the types of variation?

Answer 2

1. Continuous Variation
2. Discontinuous Variation

Question 3

What characterises continuous variation?

Answer 3

When individuals show a range of phenotypes between 2 values.
a. Determined by genes and environmental factors
b. Plotted on a line graph
c. For example - height, weight

Question 4

What characterises discontinuous variation?

Answer 4

Where differences are categorised with no intermediates
a. Not greatly affected by environmental factors
b. Represented on bar graphs/pie charts
c. For example - blood group, sex, tongue rolling

Question 5

What are the factors affecting variation?

Answer 5

1. Environmental Variation
2. Genetic Variation

Question 6

What characterises environmental variation?

Answer 6

1. Acquired characteristics that result from an individual’s activities, nutritin or environmental conditions during lifetime
2. For example - sun tan, tattoos, scars

Question 7

What characterises genetic variation?

Answer 7

1. Determined by genes in genotypes
2. Caused by mutation and shuffling of alleles in meiosis and fertilisation
3. For example - hair colour, skin colour and blood group

Question 8

What are phenotypes?

Answer 8

Observable differences/physical characteristics

Question 9

What are genotypes?

Answer 9

A constitution of genes