2.3 Flashcards
telophase
spindle fibres break down
nuclear envolopes form
nuclei and centrioles re form
prophase
the nucleolus breaks down and the centrioles begin to pull apart to form the spindle
cytokenisis
division of cytoplasm
contractile fibres tighten until cells seperate (animal)
cellulose wall builds up from the inside outward (plant)
two identical daughter cells formed
metaphase
nucelar enveloped breaks down
centrioles moved to opposite poles forming microtubials aka spindle fibres
chromatids apear to jossle about on the equator
eventually line up with each centromere assosciated with a microtubial
anaphase
chromatids split
drawn centromere first towards the poles
cannot move on their own, rely on microtubials
sporeulation
product of asexual spores that are capable of growing into new individuals
can survive adverse conditions
easily spread over large surface area
most common in fungi and plants
budding
outgrowth from the parent that producess a small, but identical individual produced from mitotic cell division
the bud eventually becomes detached and has a independant existance
dry mass
most accurate way of measuring growth
remove water from organisms
kills it so no further growth can be recorded
grow large samples of geneticaly identical organisms then randomly sample them removing water
usefull for plants but unethical for animals
regeneration
form of asexual reproduction when organisms replace part of the body that has been lost
fragmentation
when organisms reproduce themselves from fragments of their body
cell cycle
interphase
-cell grows and develops
-chromosomes replicate becoming chromatids
-organelles synthesised
mitosis
cytokenesis
vegative propagation
sophisticated version of reproductive budding
occurs in flowering plants
often involves pernating organs which stores food from photosynthesis
e.g bulbs and runners
interphase
normal metabolic proceses continue
chromasomes replicate
new cytoplasm and cell organelles synthesised
atp production stepped up
recombenant alleles
process by which pieces of DNA are broken and recombined to produce new combinations of alleles
crossing over occurs in same homologous pair
only half recombinant
or less if crossing over doesn’t occur
when is crossing over
prophase 1