What does fertile mean?

Able to reproduce and produce offspring.

Why are a horse and a donkey different species?

They can mate, but their offspring, the mule, is sterile.

The offspring of parents from two different species.

What is courtship behaviour?

Behaviour by partners before mating that makes mating more likely to succeed.

Why is courtship a necessary precursor to mating?

It stimulates and synchronises the partners and shows that a mate is suitable and ready, so mating is more likely to succeed.

What is meant by species recognition?

Identifying a member of your own species, usually by its courtship signals.

Give three examples of courtship signals.

Calls or songs, visual displays or flashing lights, and chemical signals (also dances or gifts).

Why is species recognition an advantage?

Mating only occurs between members of the same species, giving fertile offspring and avoiding wasted gametes and energy.

Why are courtship signals often species-specific?

So that females respond only to males of their own species, preventing mating between related species.

Two groups mate and produce healthy offspring that are sterile. Same species or different?

Different species, as the offspring are not fertile.

How should you use data on responses to courtship signals?

Quote and compare figures for own species and other species, then link to species recognition.

Species and courtship behaviourAQA A-Level Biology: Flashcards

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When do two organisms belong to the same species?

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When do two organisms belong to the same species?: When they are able to produce fertile offspring.
What does fertile mean?: Able to reproduce and produce offspring.
Why are a horse and a donkey different species?: They can mate, but their offspring, the mule, is sterile.
What is a hybrid?: The offspring of parents from two different species.
What is courtship behaviour?: Behaviour by partners before mating that makes mating more likely to succeed.
Why is courtship a necessary precursor to mating?: It stimulates and synchronises the partners and shows that a mate is suitable and ready, so mating is more likely to succeed.
What is meant by species recognition?: Identifying a member of your own species, usually by its courtship signals.
Give three examples of courtship signals.: Calls or songs, visual displays or flashing lights, and chemical signals (also dances or gifts).
Why is species recognition an advantage?: Mating only occurs between members of the same species, giving fertile offspring and avoiding wasted gametes and energy.
Why are courtship signals often species-specific?: So that females respond only to males of their own species, preventing mating between related species.
Two groups mate and produce healthy offspring that are sterile. Same species or different?: Different species, as the offspring are not fertile.
How should you use data on responses to courtship signals?: Quote and compare figures for own species and other species, then link to species recognition.

Exam questions on Species and courtship behaviour

A horse has 64 chromosomes in each body cell and a donkey has 62. A horse and a donkey can mate and produce a healthy offspring called a mule. A mule has 63 chromosomes in each body cell. Mules have never been reported to produce offspring of their own.
Explain why the horse and the donkey are classified as separate species even though they can mate.2 marks
Two closely related species of fruit fly live in the same forest. In species P, the male produces a courtship song by vibrating one wing, with pulses 40 milliseconds apart. In species Q, the male's song has pulses 70 milliseconds apart. In a laboratory test, females of species P accepted a male for mating after hearing a song with 40 millisecond pulses, but almost never after hearing a song with 70 millisecond pulses.
Explain why courtship behaviour is a necessary precursor to successful mating.2 marks
Two species of firefly live in the same meadow. The males of each species fly at night and give a pattern of flashes that is different in each species. A female on the ground replies with a single flash after a fixed delay. A researcher imitates the flash pattern of species X with a torch. Females of species X replied on 85% of the occasions, but females of species Y, a related species, replied on only 6% of the occasions.
Explain the role of the flash patterns in species recognition in the fireflies.3 marks

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Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).