Module 4 - Species and taxonomy

Question 1

2 marks

During courtship males of a bird species vibrate their wings which produces a sound.
Explain how this sound helps to ensure that the female mates only with a male of the same species.

Answer 1

• Female recognises own species sound
• Respond to that soundy only
• Courtship sequence continues

Question 2

1 mark

Define phylogenetic classification

Answer 2

Grouped according on evolutionary orgins.

Question 3

1 mark

Define heirachy

Answer 3

Smaller groups within larger groups with no overlap

Question 4

2 marks

Explain why biologists use protein structure to investigate the realtionship between different species of cranes.

Answer 4

1. More closely related species have more similarities in amino acid sequence
2. In same protein
3. Amino acid sequence is related to DNA base/triplet sequence;

Question 5

2 marks

Explain why temperatures could be used to find the % of DNA hybridisation

Answer 5

Higher temperature= more energy required= the higher the percentage DNA hybridisation = more bases are similar
Correct reference to breaking hydrogen bonds / more/less hydrogen bonds being present;

Question 6

2 marks

Describe how organisms are grouped in a phylogenetic classification system.

Answer 6

1. Heirachy (smaller groups within larger groups) with no overlap
2. Grouped according to evolutionary origins

Question 7

2 marks

Give 2 ways in which courtship increases the probability of successful mating

Answer 7

1. Attracts / recognises same species
2. Attracts / recognises opposite sex
3. Indication of sexual maturity
4. Stimulates release of gametes
5. Form pair bond

Question 8

2 marks

The biologists analysed the amino acid sequences of the blood protein samples from these hummingbirds. Explain how these sequences could provide evidence as to whether the crimson topaz and the fiery topaz are different species

Answer 8

1. Different species would have different amino acid sequences
2. Amino acid sequence is the result of DNA base sequence

Question 9

1 mark

Cytochrome c is more useful than haemoglobin for studying how closely related different organisms are. Suggest one reason why.

Answer 9

All organisms respire / have cytochrome c

Question 10

1 mark

Define genetic diversity

Answer 10

Number of different alleles of each gene.