3.4 Topic 4 - 3.4.7 Investigating diversity

Question 1

What are 3 technologies that have been useful for clarifying evolutionary relationships?

Answer 1

Genome sequencing, comparing amino acid sequences and immunological comparisons.

Question 2

What does genome sequencing determine?

Answer 2

It determines the entire base sequence of an organisms DNA.

Question 3

What is the sequence of amino acids in a protein coded for by?

Answer 3

The base sequence in DNA.

Question 3

What technologies have changed the way in which genetic diversity is assessed?

Answer 3

Gene technologies.

Question 4

_ _ _ _ _ _ _ determine different characteristics.

Answer 4

Alleles.

Question 4

What do similar proteins bind to?

Answer 4

The same antibodies.

Question 5

What will different alleles of the same gene have? What will they also produce?

Answer 5

Slightly different DNA base sequences.
Slightly different mRNA base sequences and may produce proteins with slightly different amino acid sequences.

Question 6

What does comparing the DNA base sequences of the same gene in different organisms in a population allow scientists to find out?

Answer 6

How many alleles of that gene there are in that population.

Question 7

What is variation?

Answer 7

The differences that exists between individuals.

Question 8

What are two factors which cause variation within a species?

Answer 8

Genetic factors and environmental factors.

Question 9

What are examples of environmental factors which cause variation within a species?

Answer 9

Climate, food and lifestyle.

Question 10

What do you have to sample to study variation?

Answer 10

A population.

Question 11

You can use the _ _ _ _ to look for variation between samples.

Answer 11

Mean.

Question 12

What is the mean?

Answer 12

The mean is an average of the values collected in a sample.

Question 13

What is the formula you use to find the mean?

Answer 13

Total of all the values in your data/the number of values in your data.

Question 14

What distribution does a bell-shaped graph show?

Answer 14

A normal distribution.

Question 15

A normal distribution in _ _ _ _ _ _ _ _ _ _ _ about the mean.

Answer 15

Symmetrical.

Question 16

What does standard deviation tell you about?

Answer 16

It tells you how much the values in a single sample vary.

Question 17

Standard deviation is a measure of what?

Answer 17

The spread of values about the mean.

Question 18

What does a large standard deviation mean?

Answer 18

That the values in the sample vary a lot.

Question 19

What does a small standard deviation mean?

Answer 19

That most of the sample data is around the mean value, so only varies a little.

Question 20

What does a graph which is steep tell you about the standard deviation?

Answer 20

That the values are similar and close to the mean so therefore the SD is small.

Question 21

What does a graph which is wide tell you about the standard deviation?

Answer 21

That the values vary a lot so therefore the SD is large.

Question 22

What bars can you draw with standard deviation?

Answer 22

Error bars.

Question 23

What do error bars do with standard deviations?

Answer 23

Error bars extend one SD above and one SD below the mean. This means that the total length of the error bar is twice the SD.

Question 24

On an error bar what does the longer the bar mean?

Answer 24

Means the larger the SD is and the more spread out the sample data is from the mean.

Question 26

Early estimates of genetic diversity were made by looking at …

Answer 26

… the frequency of measurable or observable characteristics in a population.

Question 27

What do alleles determine?

Answer 27

Different characteristics.

Question 28

A wide variety of each characteristic in a population indicates …

Answer 28

… a high number of different alleles - a high genetic diversity.

Question 29

What gene technologies have now been developed that allow us to measure genetic diversity directly?

Answer 29

• Different alleles of the same gene will have slightly different DNA base sequences. Comparing the DNA base sequences of the same gene in different organisms in a population allows scientists to find out how many alleles of that gene there are in that population.
• Different alleles will also produce slightly different mRNA base sequences, and may produce proteins with slightly different amino acid sequences, so these can also be compared.

Question 30

What can new technologies be used to give and compare?

Answer 30

• More accurate estimates of genetic diversity within a population or species.
• The genetic diversity of different species to be compared more easily.