producing new cells Flashcards
what is cell division
the increase of the number of cells in an organism
what is mitosis
the division of the nucleus
why is mitosis important
it produces new cells for growth and repair
they way in which single-celled organisms reproduce
what is stage 1 of mitosis
chromosomes become visible in the nucleus
what is stage 2 of mitosis
the chromosomes shorten and thicken and replicate to become chromatids
what is stage 3 of mitosis
the membrane around the nucleus disappears and the chromatids line up at the equator of the cell, spindle fibers now attach to them
what is stage 4 of mitosis
the chromatids are pulled apart by spindle fibers, separated into chromosomes
the newly separated chromosomes then move to opposite ends of the cell
what is stage 5 of mitosis
the nuclear membrane forms round the chromosomes
the cytoplasm then divides
what is stage 6 of mitosis
two identical daughter cells are formed
what is a multicellular organism
an organism made from more than one cell
what is the hierarchy for the process of specialisation of cells
cell-> tissue-> organ-> system
what is a cell
the smallest unit of life
what is a tissue
group of specialized cells to perform a particular function
what is an organ
several tissues coordinated to perform one or more functions
what is a system
group of related tissues and organs
why would cells look different or have different structures
the type of cell
the function of the cell
why may cells differ in size with each other
size
shape
number and types of structures inside
biochemistry
describe a red blood cell
biconcave in shape
no nucleus to increase space for haemoglobin
describe a sperm cell
has a tail to swim to meet and fuse with an egg cell during fertilisation
lots of mitochondria to provide energy for swimming action
what are stem cells
unspecialised cells which can divide to self renew, they have potential to become different types of cells
what are the two main types of stem cells
embryonic stem cells
adult stem cells
what is an embryonic stem cell
stem cells that have the potential to divide and develop into any type of specialised body cell
what is an tissue stem cell
stem cells that divide to replenish all types of differentiated cells in a specific tissue.
what is chromosome complement
the number of complete chromosome set in a cell
what is a chromotid
one of two identical halves of a chromosome that have been replicated during mitosis
