cell division Flashcards
what does nucleus contain
chromosomes made of dna
what are chromosomes made of
dna
what happens during the cell cycle
genetic material is doubled then divided into two identical cells
how many stages are there in the cell cycle
3
what are stages of the cell cycle
growth, mitosis, followed by cell divison
what happens to a cell in stage one before it divides
needs to grow and increase the number of sub cellular structures such as ribosomes and mitochondria the dna replicates ti make two copies of each chromosome
what happens to the nucleus during mitosis
one set of chromosomes is pulled to each end of the cell and the nucleus divides
what happens in stage 3 of the cell cycle after mitosis
the cytoplasm and cell membrane divide to make two identical cells
why is crll division by mitosis important
needed for growth and development of multicellular organism
what is a stem cell
an undifferentiated cell which is able to differentiate and divide to firm lots of cells of the same type
what are meristems
plant stem cells that cab differentiate into any type of plant cell throughout the life of the plant
what can plant stem cells be used for
clones of plants quickly and economically
what are advantages of embryonic stem cells
can develop into most other types of cells, each cell divides ever 30 minutes, low chance of rejection and painless
what are disadvantages of enbryonic stem cells
cause death to embryo, unreliable and embryos cant give consent
what are disadvantages of adult stem cells
risk of injection from operation, painful to donate stem cells and they are safe
what are the advantages of adult stem cells
permission can be given to collect stem cells and they are safe
why do scientists have concerns about the use of stem cells
could cause cancer
what are the siurces of adult stem cells
bone marriw, umbilical cord, blood, skin
why might stem cells from embryos be more useful than adult stem cells
become more types of cells
what happens during the process of theraputic cloning
an embryo is produced with the same genes as the patient
what are the advantages of therapeutic cloning
may cure diseases, produce replacement cells, treat diabetes and paralysis. cells unlikely to be rejected, cells and tissues of any tupe can be made, many cells are produce and reduces waiting time for transplants
what are disadvantages of therapeutic cloning
potential life is killed, shortage of egg donors, nay transfer viral infection, poor success rate,
why do most organisms gave an even number of chromosomes in their body cells
chromosomes come in pairs
