Specialised Cells Flashcards
What is a specialised cell?
A cell that has a structure adapted to their function
What type of cells are egg and sperm cells?
They’re haploid cells - a cell that contains only half of the numbers of chromosomes of that of a normal cell/diploid
Why do egg and sperm cells only carry half of the number of chromosomes in a diploid cell?
So in sexual reproduction when the two cells fuse to create a fertilised egg which will then develop into an embryo, the nucleus will have a full set of chromosomes
What are the main functions of an egg cell?
To carry the female’s DNA and to nourish the developing embryo in the early stages
How is the egg cell adapted to do this?
It contains nutrients in the cytoplasm to the feed the embryo.
It has a haploid nucleus.
Straight after fertilisation, its membrane changes structure to stop any more sperm getting in. This ensures the offspring will have the correct amount of DNA
What are the main functions of a sperm cell?
To carry the male’s DNA to the female’s egg
How is the sperm cell adapted to do this?
It has a long tail so it can swim to the egg.
It has lots of mitochondria to provide energy need to swim the distance.
It has an acrosome at the front of the ‘head’ where it stores enzymes to digest its way through the membrane of the egg cell.
It has a haploid nucleus
What are the main functions of a ciliated epithelial cell?
To move materials
Where are they found?
Lining the surfaces of organs
How is the ciliated epithelial cell adapted to do this?
They have cilia - hair-like structures - on the tope surface of cells. These beat to move substances in one direction, across the surface of the tissues.
For example, what do the ciliated epithelial cells in the airways move?
They move mucus up the throat so it can be swallowed and does not reach the lungs.
