reproduction and inheritance Flashcards
what is the role of FSH in the menstrual cycle
stimulates the follicle to develop and ovum matures
the maturing follicle releases oestrogen
what is puberty
period in which adolescents start to develop secondary sexual characteristics
what is the role of oestrogen in the menstrual cycle
inhibits FSH production - stops another ovum being matured
thickens uterus lining
stimulates LH production
what is the role of LH in the menstrual cycle
ovulation - follicle on ovary releases mature ovum into oviduct
remanent of follicle becomes corpus luteum
what is the role of progesterone in the menstrual cycle
FSH and LH inhibited - stops further ovum being matured + released
thickness of uterus lining is maintained
what happens in stage one of the menstrual cycle and what is it called
period of bleeding as the uterus lining breaks down
menstruation
what is the stamen
the male organ of the flower
anther and filament combined
what is the anther
part of the stamen where pollen is produced
what is the filament
the stalk that holds up the anther
what is the carpel
the female organ of the flower
stigma + ovary + style
what is the stigma
the sticky tip that pollen attaches to
what is the style
the stalk that holds up the stigma
stalk that the pollen tube grows down
what are the ovaries (flower)
the structure that contains the ovules
what are the two neutral parts of a flower
sepal
petal
what are petals for
modified leaves used to attract insects
what is the sepal for
outer green part of the flower that encloses the flower bud whilst it develops
what is pollination
process during plant reproduction where pollen grains need to move from the anther of one flower to the stigma of another flower
what are the two types of pollination
self - pollination
cross - pollination
what is self pollination
the transfer of pollen from the anther of one plant to the stigma of the same plant
what is cross pollination
the transfer of pollen grains from the anther of one plant to the stigma on a different plant
adaptations for insect pollination in flowers
brightly coloured petals that attract insects
nice scents that attract insects
big, sticky pollen grains that stick to insects bodies
sticky stigmas so when pollen rubs off insects it will stick to the stigma
nectaries that produces sugar nectar which attracts insects
adaptations for wind pollination in flowers
lots of small, light pollen grains that get blown long distances in the wind
long filaments so anthers hang out of the flower + pollen blown away more easily
feathery stigmas that can trap lots of passing pollen grains
what is a haploid cell
a cell that contains half the genetic material than a normal cell
how many chromosomes does a human gamete have
23
what is formed when two haploid cells join
a diploid cell
during meiosis how many times does the cell divide
2
as a result of meiosis how many new cells are formed
4
are the cells produced by meiosis genetically identical or unique
unique
what are the reasons why new cells are constantly required
growth
repair
development
what do we commonly call the cells produced by mitosis
daughter cells
are the cells produced by mitosis genetically identical or unique
identical
