Sperm cell adaptations

Biology · Cell structure

tap a part of the sperm ↓

Two animal cells, completely different shapes. The sperm's extras are all there for its one job: reaching the egg and fertilising it.

Tap each part of the sperm cell to see what it lets the sperm do. Then switch the labels off and test yourself.

What you need to know

• A specialised cell's structure — its shape and the parts inside it — adapts it to one specific function. A sperm cell looks very different from the model animal cell.
• A sperm cell is the male sex cell. Its function is to swim through the cervix and uterus to the egg cell and fertilise it, forming a zygote.
• Its four adaptations are a tail, many mitochondria, an acrosome containing enzymes, and a haploid nucleus.
• Haploid means half the number of chromosomes, so the sperm nucleus and the egg nucleus together give the zygote a full set.

The big picture

A sperm cell is a specialised cell: its shape and the parts inside it are built for one job. That job is to swim through the cervix and uterus, reach the egg cell and fertilise it, forming a zygote. A tail lets it swim, many mitochondria release the energy for that movement, and the acrosome's enzymes break down the egg cell membrane. Its haploid nucleus carries half the number of chromosomes, so the zygote ends up with a full set.

⚠ Watch out

Saying mitochondria "make energy". Energy is released by aerobic respiration, which happens in the mitochondria — it isn't made from nothing.

Memory hook

Think of the sperm's kit list for one journey: a tail to TRAVEL, mitochondria for POWER, an acrosome to get IN, and a nucleus with HALF. Travel, power, in, half.

Check yourself

Switch the labels off on the diagram. Can you name all four adapted parts of the sperm cell and say, in one sentence each, what each part lets the sperm do?