Homeostasis 2 Flashcards
The Menstrual cycle and Puberty, Contraception, IVF, Plant hormones
What is puberty?
period when adolescents develop secondary sexual characteristics
what is stage 1 of the menstrual cycle?
what is stage 2 of the menstrual cycle?
what is stage 3 of the menstrual cycle?
what is stage 4 of the menstrual cycle?
STAGE 1 = menstruation
- bleeding
- breakdown of the uterus lining (4 days)
STAGE 2 = uterus lining starts building up
- prepare for fertilised egg (10 days)
STAGE 3 = ovulation (1 day)
- egg is released from the ovaries
STAGE 4 = maintaining the uterus lining (14 days)
- If no fertilised egg reaches then its back to stage 1
- if there is a fertilised egg then it is implanted into the uterus lining to develop into a foetus
In which stages does oestrogen and progesterone increase?
oestrogen = stage 2
progesterone = stage 4
What are the functions of LH and FSH?
FSH = stimulates egg to mature in the ovaries
LH = stimulates the release of egg during ovulation
Does Progesterone inhibit or stimulate the growth of LH and FSH?
Does oestrogen inhibit or stimulate the growth of FSH?
What does FSH do in response to this?
Does oestrogen inhibit or stimulate the growth of LH?
- inhibit
- inhibit
- it stimulates the ovaries to produce oestrogen
- stimulates
what is contraception?
- artificial methods to prevent pregnancy
What does oestrogen and progesterone do to prevent pregnancy?
oestrogen = releases everyday, inhibits growth of FSH = no egg will mature
progesterone = stimulates the production of a thick mucus in the cervix = prevents sperm reaching
what are some hormonal contraceptive methods?
contraceptive pills
contraceptive injection
contraceptive implant
contraceptive patch
IUD - (3+ years) = intrauterine device
Name some non hormonal contraceptive methods?
condoms
diaphragm
sterilisation
Which of the three non hormonal contraceptive methods prevents against sexually transmitted diseases?
condoms
which of the three non hormonal contraceptive methods is permanent ?
sterilisation
When is IVF used?
where does the fertilisation take place?
what happens if a man has a low sperm count?
Where are the fertilised eggs left
when couples can’t get pregnant
in a lab
ICSI = Intracytoplasmic sperm injection
in an incubator
Name some consequences of IVF
- emotional and stressful
- doesn’t always work
- painful
- can lead to multiple births at the same time
what do plants use to respond to the environment?
hormones
Once auxins are produced what happens?
Does this stimulate growth in both the shoots and roots?
The auxins dissolve in the solution of the cells and diffuse backwards along the shoot/root
This stimulates growth in the shoots only and inhibits growth in the roots
What are the shoots in terms of phototropic and geotropic?
What are the roots in terms of phototropic and geotropic?
positively phototropic
negatively geotropic
negatively phototropic
positively geotropic
Which two places in a plant do the auxins accumulate at?
- the shaded side
- the lower side rather than the upper side
what do auxins control?
the growth of the shoots and roots
What is phototropism?
what is geotropism?
- response to light
- response to gravity
In the roots, which side(lower or upper) grows?
Why is this?
upper
in the roots auxins inhibit growth
What two things can auxins be used for?
- used to kill weed
- stimulate growth
how does gibberellin help in inducing flowering?
- it can help flowers to grow bigger or increase in population`
what are the three uses of gibberellin?
- inducing flowering, controlling dormancy and growing larger fruit
what is dormancy?
how does gibberellin help with germination?
the period before growth starts in a plant
it helps the growth of a plant in times when it usually doesn’t grow
how does gibberellin help in growing larger fruit?
helps seedless fruits to grow as large a seeded fruits
What does ethene do in a plant?
stimulates the ripening of fruit