biology topic 1 - 4 Flashcards
What is a eukaroyotic cells?
Are organisms that are made up of eukaryotic cells.
what is a prokarotic cell?
its a single cell organisims.
what is the nucleus?
contains genetic material that controls the activity of the cell
what is the cytoplasm?
A gel like substance where most chemical reactions happen.
what is the cell membrane?
hold the cell together and controls what goes in and out.
what is the mitochondria ?
these are where most of the reactions for aerobic resperation takes place.
what are ribosmes?
these are where proteins are made in the cell
what is the rigid cell wall
its made of cellulose. it supports the cell and strengthens it.
what is the permant vacuole?
contains cell sap, a weak solution of sugar and salts.
what is chlorplast
these are where photsythesis ocurrs which makes food for the plant.
give two advantages of using eletron microscopes?
they have a much higher reslotion and a higher magnification.
what is the eqation for magnification?
image/ real size
what is differenation?
is the process by which a cell changes to become a specilised for its job.
what are sperm cells good for?
reproduction
what are nerves good for?
rapid signalling.
what are muscles cells good for?
contraction- makes it quickly contract.
what are root hair cells good for?
absorbing water and minerals
what is the phloem and xylem good for?
transporting substances.
how many chromosmes does a human have?
23 pairs
what is a chromosmes.
are colied up lenghts of DNA molescules
what does a chromosome carry
each one carries a large number of genes.
what is binary fission?
reproducing prokaryotic cells using a simple cell divsion.
how many stages are there in binar fission.
4
what are the steps to binary fission.
1) The circular DNA and plasmids repilcate.
2) The cells gets bigger and the circular DNA strands move to opposites ends of the cell
3) The cytoplasm begins to divide and new cel walls begin to form.
4) the cytoplasm divides and two daughter cells are made.
