Advantages of asexual reproduction: • only one parent needed • more time…

The idea

Asexual reproduction produces genetically identical offspring from one parent, without gametes or fertilisation. Because no mate must be found, the organism saves the time and energy that sexual reproduction would spend on courtship, gamete production and pollination. Reproduction can therefore be rapid, and in favourable conditions a single parent can generate many identical offspring, quickly colonising a garden, field or pond. For example, a strawberry plant sends out runners and a bacterium divides by binary fission, each producing clones suited to the current environment. The trade-off is lack of genetic variation, so if conditions change, all identical offspring may be equally vulnerable. The skill is to explain each advantage in terms of time, energy, speed or offspring number, and to link it to favourable conditions.

What earns the marks

• Only one parent is needed, so a mate does not have to be found and fertilisation is not required.
• No time or energy is spent finding a mate, producing gametes or attracting pollinators, so more resources go into growth and offspring.
• Asexual reproduction is faster than sexual reproduction, allowing rapid population increase.
• Many identical offspring can be produced when conditions are favourable, so the parent genotype is multiplied quickly.
• Named examples such as runners in strawberry plants, tubers in potatoes or binary fission in bacteria illustrate the advantages.

Common mistakes and how to put them right

• Writing that asexual reproduction produces genetically different offspring.

  Put it right: It produces genetically identical offspring, which is why it is described as cloning.

• Saying asexual reproduction is always better than sexual reproduction.

  Put it right: It is advantageous in favourable, stable conditions but risky if the environment changes.

• Confusing energy efficiency with producing no energy.

  Put it right: The organism saves energy because it does not need to find a mate or make gametes.

Exam tips

• Use the phrase genetically identical rather than similar when describing asexual offspring.
• For each advantage, add a consequence, such as rapid colonisation or preservation of a successful genotype.
• When comparing with sexual reproduction, refer explicitly to finding a mate, gamete production and speed.