Science inheritance revision Flashcards
what is meiosis
the division of cells to produce gametes
what are the five stages of cell division? (IPMAT)
interphase, prophase, metaphase, anaphase, telophase
what happens in interphase
the chromosomes replicate but aren’t visible
what happens in prophase
chromosomes “wind up”, the nuclear membrane breaks down and the centrioles move
what happens in metaphase
spindle fibers form, chromosomes attach to spindle fibers in the middle in the homologous pairs
what happens in anaphase
chromosomes get split and separated by the spindle fibers
what happens in telophase
the original cell divides into 2 by the cell membrane pinching in (cytokinesis)
what are three different types of inheritance?
mendellian, codominance and incomplete
what is mendellian inheritance
one trait is dominant over the other. e.g. Bb, bb
what is codominance
both alleles are expressed. e.g. BB, WW = BW
what is incomplete dominance
both alleles blend. e.g. RR, WW = RW
genotype is expressed through
letters, e.g. BB, bb
phenotype is
the way in which a trait is expressed, e.g. curly hair
