4. The concept of species and courtship

Question 1

A species is:

Answer 1

A group of similar organisms

That are able to successfully reproduce

To give fertile offspring

Question 2

Courtship behaviour 5pts

Answer 2

Is species specific – only members of the same species respond.

Allows identification of a mate (of the opposite sex) that is capable of breeding – sexually mature or fertile.

May lead to pair bonding which will increase the survival chances of offspring.

Synchronises mating.

Can causes a potential mate to become able to breed – enter oestrous.

Question 3

But there are problems with using courtship behaviours alone to classify living organisms.
Which are?

Answer 3

Bacteria do not have separate sexes to require the attraction of a mate – they mate by binary fission
It is impossible to observe mating behaviours in extinct organisms
Plants do not display courtship behaviours
Two seemingly different species – a horse and a donkey – may be able to mate but the offspring produced – a mule is infertile – this questions the fundamental definition of species.

Question 4

Simple courtship behaviours: 3pts

Answer 4

Releasing pheromones (chemicals)
Mating calls
Visual displays
can all be used to attract a mate

Question 5

Complex courtship behaviours:2pts

Answer 5

Dancing
Building
can all be used to attract a mate

Question 6

Questions

Answer 6

Question 7

More questions

Answer 7

Question 8

(f) Suggest two advantages of male snakes courting with longer females.

Answer 8

(Parent/offspring)

1. Produce more / larger offspring / eggs;
2. Better predators/ fitter/ more successful at gaining food / less likely to be eaten / more able to protect offspring / eggs;

3.(More) sexually mature / fertile;

4. Have more food stores for offspring / eggs;

Question 9

Even more

Answer 9

Question 10

. Vibration of the wings by the male allows the female to ….

Answer 10

Recognize a male of the same species
Identify a male that is mature enough/capable of mating
Stimulates mating behavior in the female.

Question 11

Study showed that females mated MOST QUICKLY when played their species-specific song,

Answer 11

so the results do support the hypothesis.
- HOWEVER it could have been the sight of the song less male that stimulated the behaviour rather than the synthesized song.
- The results suggest that females of other species also responded but less quickly.

Question 12

To standardise the song,

Answer 12

the song played to all females was the same and the experiment was repeatable so that the experiment would give valid results,
- showing that it was the song that caused the response in the females and not another factor such as pauses in the song.