Specialised Cells Flashcards
What are specialised cells?
Cells that have structures which make them adapted to their function
List 3 examples of specialised cells.
- Egg cells
- Sperm cells
- Ciliated epithelial cells
What are egg cells and sperm cells specialised for?
Reproduction
Describe how an egg cell and sperm cell interact during the process of sexual reproduction.
- Nucleus of egg cell fuses with nucleus of sperm cell to create a fertilised egg
- This develops into an embryo
What are the functions of an egg cell?
- Carry female DNA
- Nourish developing embryo during early stages
Explain the ways in which an egg cell is adapted to carry out its function.
- Contains nutrients in cytoplasm to feed embryo
- Its membrane hardens after fertilisation, stopping excess sperm from getting in - this ensures offspring end up with correct amount of DNA
- Has a haploid nucleus
What is the function of a sperm cell?
To transport the male’s DNA to the female’s egg
Explain the ways in which a sperm cell is adapted to carry out its function.
- Has a long tail so it can swim to the egg
- Has lots of mitochondria in middle section to provide energy from respiration to swim
- Has an acrosome at the front of its ‘head’, where it stores enzymes needed to digest the membrane of egg cell
- Contains a haploid nucleus
Why is it important both the egg cell and sperm cell have a haploid nucleus?
When their nuclei combine at fertilisation, the resulting cell will have the correct number of chromosomes
What is the function of ciliated epithelial cells?
To move substances
Explain the ways in which ciliated epithelial cells are adapted to carry out their function.
- They line the surfaces of organs
- Some have cilia on top surface of cell
- Cilia beat to move substances in one direction, along surface of tissue
- (e.g. they line the airways to move mucus up to the throat to be swallowed)
