Topic 1- key concepts Flashcards
What is a prokaryotic cell?
A cell without a nucleus
What is a eukaryotic cell?
Cell with a nucleus
What is the function of the nucleus?
Contains the cells genetic material (DNA and RNA)
What is the function of the mitochondria?
Uses aerobic respiration to transfer energy
What is the function of the cytoplasm?
Where chemical reactions take place
What is the function of the ribosomes?
Site of protein synthesis
What is the function of the cell membrane?
controls what enters and leaves the cell
What is the function of the cell wall?
To protect and support the cell
What is the function of the chloroplasts?
Site of photosynthesis (green pigment chlorophyll absorbs necessary sunlight)
What is the function of the vacuole?
Contains cell sap, maintains internal pressure to support the cell
What is the function of chromosomal DNA?
It is one long circular chromosome which controls the cells activities and replication. It floats in the cytoplasm
What is the function of plasmid DNA?
Small loops of extra DNA which aren’t part of the chromosome; contain genes for things like drug resistance and can be passed between bacteria
What is the function of the flagella?
Rotates to help the bacterium move
How are egg cells specialised?
They have a large store of nutrients in the cytoplasm, a haploid nucleus and changes in the cell membrane after fertilisation to stop any more sperm getting in
How are sperm cells specialised?
Long tail and streamline head to help it swim to the egg. Lots of mitochondria in the cell to provide the energy needed. Carries enzymes in its head to digest through the egg cell membrane
How are ciliated epithelial cells specialised?
Have small hairs (cilia) which can sweep substances along
What are the advantages of light microscopes?
- Inexpesive
- Easy to use
- Portable
- Observe both dead and living specimens
- Can view specimens in colour
What are the disadvantages of light microscopes?
Limited magnification and limited resolution