✓ Revise Right course
Gametes are specialised reproductive cells that contain half the normal number of chromosomes (haploid). Free notes with key terms and 12 questions answered.
Gametes in Sexual Reproduction is part of Reproduction in GCSE AQA Higher Biology.
4 min
Reading time
27
Lessons in this topic
GCSE AQA Higher
Pathway
Reviewed by Revise Right
Content review
Gametes are specialised reproductive cells that contain half the normal number of chromosomes (haploid). Free notes with key terms and 12 questions answered.
AQA GCSE Biology mock draft, 26–31 Oct. Draft coverage: Biology Paper 1 (Higher tier). Reviewed for an original-practice sitting; check student availability before registering. Marking and results will follow later, after separate approval. Eligible new accounts receive a five-day Pro trial when signup email verification completes. Previous trials keep their original expiry. After expiry, new papers need Pro unless you have an explicitly confirmed free sitting offer for this event. That offer adds no Pro time or AI learning. Saved attempts and released results remain readable. No card or automatic charge.
Use this lesson to stay inside Reproduction while connecting the detail back to the wider Inheritance, variation and evolution topic.
Read the core explanations from Gametes in Sexual Reproduction before testing yourself from memory.
Think about why you don't look exactly like your parents or siblings. The answer lies in tiny specialised cells called gametes. These cells are the key players in sexual reproduction - the process that creates the incredible diversity of life around us.
Trap: Many students think gametes have the same number of chromosomes as body cells. Actually, gametes have exactly half - this is crucial because when two gametes fuse, they create offspring with the correct chromosome number, not double.
In animals, sexual reproduction involves two very different types of gametes. Picture a human sperm cell - tiny, with a long tail for swimming. Now picture an egg cell - much larger, packed with nutrients. These differences aren't random - they reflect each cell's specific job.
The size difference makes sense when you think about function. Sperm cells need to be small and fast to swim through the female reproductive system. Egg cells need to be large because they provide all the initial nutrients for the developing embryo after fertilisation.
Flowering plants also use sexual reproduction, but their gametes work differently from animals. Plants can't move around to find a mate, so they've evolved clever solutions. The male gametes are found inside pollen grains, while female gametes are egg cells inside the ovules.
Here's where students often get confused: pollen grains aren't the actual male gametes. Think of pollen as a protective package - inside each pollen grain are the actual male gametes. When pollen lands on a stigma, it grows a pollen tube that delivers the male gametes to the egg cell in the ovule.
Sexual reproduction involves the joining (fusion) of male and female gametes. This process is called fertilisation, and it's the moment when genetic material from two parents combines to create a unique offspring.
Worked example: The Process of Fertilisation
Describe what happens when male and female gametes fuse during sexual reproduction
Answer: Fertilisation produces a zygote with genetic material from both parents, leading to genetic variation in offspring
Key insight: This fusion is why sexual reproduction creates genetic variation. Each parent contributes different versions of genes, so the offspring gets a unique combination. This is completely different from asexual reproduction, where offspring are genetically identical to the parent.
Gamete questions appear regularly in GCSE exams, and there are specific ways to phrase your answers that examiners are looking for. Here's how to maximise your marks.
Exam depth extension: In gametes in sexual reproduction, connect what are gametes and why do they matter? to animal gametes - sperm and egg cells using clear cause-and-effect statements. When you explain biological processes, include what changes, why it changes, and the consequence for cells, organisms, or populations. If calculations appear, show each step, include units, and end with a sentence that interprets the result in biological context.
Common exam mistake: Students often write 'pollen and ovule' as the plant gametes. The correct answer is 'pollen and egg cells' - the ovule contains the egg cell but isn't the gamete itself.
Remember the examiner's checklist for a full-mark answer: mention both types of gametes, use the word 'fusion', explain the chromosome contribution from each parent, and link this to genetic variation in the offspring.
Published by Revise Right. Use the official specification reference to check the requirements for your course. Content updated: 2026-03-20.
Move to the related lessons or back to the topic page when you need the wider sequence before exam-style practice.
Gametes are specialised reproductive cells that contain half the normal number of chromosomes (haploid). In animals they are sperm and egg cells; in flowering plants they are the male gametes inside pollen and the egg cells inside ovules. They fuse during fertilisation to restore the full chromosome number.
In flowering plants, the male gametes are found inside pollen grains and the female gametes are egg cells inside the ovules. The ovule contains the egg cell but is not the gamete: when pollen lands on a stigma, it grows a pollen tube that delivers the male gametes to the egg cell in the ovule.
During fertilisation, the male gamete reaches the female gamete, their cell membranes fuse, and the nucleus from the male gamete fuses with the nucleus from the female gamete. This forms a zygote, a single cell with the full chromosome number and genetic material from both parents.
Sperm cells have a tail (flagellum) so they can swim through the female reproductive system to reach the egg cell. They are small and mobile, unlike the large, nutrient-packed egg cell.
In flowering plants, pollen is transferred from anther to stigma during pollination, then the pollen grows a pollen tube to the ovule. The male gamete's nucleus fuses with the egg cell's nucleus, forming a zygote.
A sperm cell is the small, mobile male gamete with a tail (flagellum) for swimming to reach the egg. An egg cell (ovum) is the large female gamete containing nutrients and cytoplasm, because it provides all the initial nutrients for the developing embryo after fertilisation.
Gametes have half the normal number of chromosomes so that when two gametes fuse, the offspring has the correct chromosome number, not double. Half the chromosomes come from each parent, giving a full set and a unique combination that causes genetic variation.
Pollen grains are not the actual male gametes; they are protective packages that contain the male gametes. When pollen lands on a stigma, it grows a pollen tube that delivers the male gametes to the egg cell in the ovule.
An ovule is a structure in flowering plants that contains the female gamete, the egg cell, and is found inside the ovary of the flower. The ovule itself is not the gamete; the egg cell inside it is.
Egg cells are large because they provide all the initial nutrients and cytoplasm needed for the developing embryo after fertilisation. Sperm cells, however, are small and fast so they can swim through the female reproductive system.
In sexual reproduction, male and female gametes fuse, so offspring get a unique combination of genes from two parents and show genetic variation. In asexual reproduction, offspring are genetically identical to the parent.
In an exam answer, the plant gametes are the male gametes in pollen and the egg cells; writing 'pollen and ovule' is wrong, because the ovule contains the egg cell but is not the gamete itself.