topic 2:cell division Flashcards
what is a haploid cells
haploid cells contain one copy of each chromosome
what type of cells are haploids
Gametes (sperm and egg cells)
what are diploid cells
cells that contain two copies of each chromosome (46)
why does a red blood cell not have DNA
to contain as much oxygen as possible
what stage is a cell in when it is not dividing
interphase, when a cell is just being a cell.
why are people long sighted and how to correct
.occurs when the eyeball is too short so the image is focus behind the retina
fixed with a converging lens to bend rays before they reach the eye
what is the definition of genetically identical
an exact clone of the original cell
What is a stem cell
An undifferentiated cell
growth
define
An increase of size as a result of an increase in the number or size of cells
define a stimulus
anything your body is sensitive to
what are impulses
an electrical signal
what is a synapse
a junction between two neurons across which electrical signals pass
what are the chemicals diffuse across the synapse
neurotransmitters
what releases the neurotransmitter molecules
postsynaptic cell
Describe how the arrival of an impulse at the end of one neurone can cause an impulse in a neighbouring neurone
impulse triggers the release of a neurotransmitter (1)
neurotransmitter is released into synapse (1)
next neurone detects the
neurotransmitter (1)
new impulse is generated in the next neurone. (1)