Producing New Cells Flashcards
what does cell division allow a single celled organism to do
reproduce
what does cell division allow multicellular organism to do
repair damaged tissues and grow
why does your body need stem cells
you body needs specialised cells to grow and repair. Most specialised cells cant make copies of themselves but stem cells can
what are stems cells
stem cells are unspecialised cells which have no specific function. They have the ability to develop and differentiate into specialised cells with particular functions.
describe tissue stems cells
they are stem cells obtained from the body throughout life - they can only develop into a few types of specialised cells - multipotent
describe embryonic stem cells
embroyonic stem cells are obtained from an embryo - they can develope into any type of specialised cell - pluripotent
what is the ethical concern of using embryonic stem cells
in order to extract the embryonic stem cell you need to kill the embryo
what are some medical uses of stem cells
organ transplants
skin grafts
treat cancer/diabetes
multicellular organisms?
made of more than 1 type of cell
unicellular organisms
made of only 1 cell e.g amoeba
hierarchy in multi-cellular organism
cell–>tissue–>organ–>system
why do cells become specialised ?
to perform specific functions
what is a specialised cell
a specialised cell is a type of cell which has adapted to perform a specific function.
root hair cells (plants)
specialisation
large surface area
function of specialisation absorbs more water from soil
red blood cell
specialisation
contains haemoglobin
no nucleus
biconcave shape
function of specialisation carries more oxygen around body.
sperm cell (haha like sperm)
specialisation
has a tail
function of specialisation swim to egg for fertilisation
egg cell (haha like ovaries)
specialisation
contains a food source
function of specialisation provide developing embryo with energy
why do unicellular organisms under go cell division
to reproduce to form two new identical cells
why do multicellular organisms undergo cell division
mitosis provides new cells for growth and repair of damaged tissues and replacment of dead or damaged cells. It also maintains the diploid chromosome compliment
what is a pathogen
any bacteria, virus or microbe which can cause disease
what precautions should be taken when dealing with pathogens
aseptic techniques
give examples of aseptic technique
all equipment should be sterllised
hands washed before and after
plates used to culture microbes should be sealed and never opened
why are aseptic techniques important to the organisms you are trying to grow.
stops contamination of the plates with other microbes which will act as competitors .
what factors to cells require to grow in the lab
a suitable nutrient medium
suitable temperature
supply of oxygen
suitable pH
what is abotosis
programmed cell suicide
what is matastisis
cancer cells spreading from tumor to different part of the body through the blood stream
what is cancer
cancer is caused by cells dividing uncontrollably due to genetic code damage. They divide to form a tumor. (abnormal cell growth, fight the power)
what does haploid mean?
a cell containing only one set of chromosomes (gametes/sex cells)
what does diploid mean?
cells containing two sets of chromosomes (dip like double)
what controls cell division
the nucleus - it contains the genetic information/chromosomes and controls cell activity
what are the animal and plant gametes
animal
sperm and egg
plant
pollen and ovule
humans and guppy fish have the same amount of chromosomes, explain why they are so different
the order of bases in teh DNA that makes up the chromosome are different
what is a gene
a section of a chromosome which codes for a protein
what is DNA
carries genetic code
what is a chromosome
thread like structure containing genetic information
what is mitosis
when a mother cell divides to produce two daughter cells with identical diploid chromosome compliments
location of mitosis?
nucleus (DNA found there)
Mitosis maintains the diploid chromosomes compliment (number of chromosomes) when producing new cells
Mitosis maintains the diploid chromosomes compliment (number of chromosomes) when producing new cells
steps of mitosis
step 1) long uncoiled chromosomes not yet individualy visible
chromosomes are replicating
step 2) chromosomes shorten, thicken and replicate to form 2 i i
identical chromatids
chromosomes now visible
nuclear membrane disappears
step 3)chromosomes line up at equator of cell
spindle fibres attach to pairs of chromatids
step 4)pairs of chromatids are pulled apart and chromosomes are
pulled to opposite ends of the cell.
step 5) nuclear membrane reforms and cytoplasm divides.
step 6)two identical diploid cells are produced.
what does mitosis provide
new cells for growth and repair of damaged tisses
replacment of dead or damaged cells
it also maintains the diploid chromosome complement in each daughter cell to ensure no genetic information is lost.
