Male and female gametes
Two kinds of germ-cell.
Two different cells
In simple organisms the two germ-cells look alike. In more complex organisms they differ.
What might be different about them?
What this lesson covers
The idea
As body designs become complex, germ-cells specialise: the large germ-cell containing stored food is the female gamete, and the smaller, motile germ-cell is the male gamete.
Two different cells
In simple organisms the two germ-cells look alike. In more complex organisms they differ.
What might be different about them?
- One is large with stored food, the other is small and moves
- Both are the same size
- One is a body cell and one is a germ-cell
Compare the gametes
Open each tab.
Big and still, small and swimming
As body designs get more complex, the germ-cells become specialised. The big one holds food for the zygote to grow. The small one can move toward it. By convention, the motile one is called male and the one with the food store is called female.
As body designs become complex, germ-cells specialise: the large germ-cell containing stored food is the female gamete, and the smaller, motile germ-cell is the male gamete.
Notes
The large germ-cell with stored food is the female gamete. The smaller, motile germ-cell is the male gamete.
Check yourself
Which germ-cell is called the female gamete?
Which germ-cell is called the male gamete?
Why does the female gamete contain stored food?
- The large one containing stored food — correct. Yes!
- The smaller one that moves. The smaller, motile germ-cell is conventionally the male gamete.
- Both germ-cells, whichever joins first. The two gametes are different: the female gamete is the large one with the food store.
- The large one with the food store. The germ-cell containing the stored food is the female gamete.
- The smaller, motile one — correct. Yes!
- The one that has no DNA. Germ-cells have half the DNA of body cells, not none.
- To help it swim. It is the male gamete that is smaller and motile.
- Because it has lost its DNA. Germ-cells have half the chromosomes and half the DNA. The food store supplies the zygote with energy.
- The zygote needs enough energy to grow into an organism with specialised tissues and organs — correct. Yes!