2.13

Question 1

Living things show variation in their

Answer 1

phenotype

Question 2

Variation is important as natural selection favours

Answer 2

phenotypes that are well adapted to their environment

Question 3

Evolution occurs as a result of

Answer 3

variation and natural selection

Question 4

2 main kinds of variation:

Answer 4

discontinuous

continuous

Question 5

discontinuous variation occurs when you can put organisms into

Answer 5

definite categories

Question 6

people can be categorised into one of these groups depending on which ABO blood group they are.
There are no

Answer 6

intermediate categories

Question 7

Discontinuous variation results from one gene with

Answer 7

2 or 3 different alleles

Question 8

Environmental factors have little effect on these

Answer 8

discontinuous characteristics

Question 9

Some kinds of variation between individuals do not fall into distinct categories, such as human height, known as:

Answer 9

continuous variation

Question 10

Continuous characteristics, like height, are determined by many genes. Each of these genes may have several alleles and is known as

Answer 10

polygenic inheritance

Question 11

Polygenic inheritance is where…

Answer 11

more than one gene contributes to a phenotype

Question 12

Your height (continuous characteristic) will depend on the mixture of

Answer 12

dominant and recessive alleles that you inherit for each of the genes involved in height

Question 13

Environmental factors may play a part in characteristics that show

Answer 13

continuous variation

Question 14

An example of environmental factors on continuous characteristics such as height are:

Answer 14

children poor diet/suffer from serious illnesses = may not be able to grow as tall as they might have done if they were healthy or had a good diet

Question 15

Mean is the

Answer 15

average of a set of values

Question 16

Mean is calculated by

Answer 16

adding up values and then dividing them by total number of values

Question 17

Median is the

Answer 17

middle value of a set of values

Question 18

Median is calculated by

Answer 18

ordering values lowest to highest and removing one from each side until reach middle number

Question 19

the mode is the

Answer 19

value that occurs the most frequently in a set of values

Question 20

A normal distribution means that the curve is symmetrical about a central value and the

Answer 20

mean, median and mode are all the same

Question 21

A skewed distribution is when the

Answer 21

mean, median and mode all have different values