Hormones and IVF Flashcards
Hormones can also be used as ‘fertility drugs.’ Explain how a fertility drug helps a woman to become pregnant. (2 marks)
Contains FSH which causes egg to mature / develop / be produced. OR contains LH which stimulates the release of an egg.
In-vitro fertilisation (IVF) is used to help some women get pregnant. Name the two hormones used in IVF treatment. (2 marks)
FSH and LH
Describe the process of IVF. (4 marks)
Eggs are collected from ovary .Eggs are mixed with sperm or fertilisation occurs. Fertilised egg divides, embryos are formed. Embryos are inserted into the womb /uterus. FSH matures egg and LH releases eggs.
Explain how a contraceptive pill works. (2 marks)
Inhibits FSH (production / secretion) (therefore) no eggs mature / released.
Explain the stages of the menstrual cycle in detail. (4 marks)
FSH is produced and secreted by the pituitary gland. FSH causes the eggs in the ovaries to mature and stimulates the ovaries to release oestrogen. Oestrogen is secreted by the ovaries. Oestrogen inhibits FSH production and stimulates the pituitary gland to release LH. LH stimulates the release of the mature egg cell (ovulation – day 14). Progesterone is secreted by the ovaries. Progesterone maintains the uterus lining and inhibits production of both FSH and LH. If the egg is not fertilised, the uterus lining passes out of the body. (Period: days 1-5)
How can I remember which gland each hormone is produced by?
POP!!! Pituitary, Ovary, Pituitary Not POO or OOPs!!!
What is an auxin?
A plant hormone which affects cell elongation
If a shoot grows towards light what do we call this?
Positive phototropism
If a shoot grows away from gravity what do we call this?
Negative gravitropism
How do stems and roots respond differently to high concentrations of auxins? (2 marks)
cells in stems grow more cells in roots grow less
How are plant hormones used in industry? (2 marks)
For plant ripening As weedkillers
How does a phototropic response happen in a shoot?
Auxin accumulates on the dark side, which causes more cell elongation on this side. The tip then bends towards the light.
What does FSH do?
It matures eggs and stimulates the production of oestrogen
What does oestrogen do?
It inhibits FSH, it prepares the uterus for a fertilised egg, and it stimulates the production of LH
Which 2 hormones involved in the menstrual cycle are made in the pituitary gland?
FSH and LH
Which hormone involved in the menstrual cycle is made in the ovaries?
Oestrogen
Which hormone is found in contraceptives and how does it work?
Oestrogen - it inhibits FSH. No FSH, no mature eggs, no babies
What does a selective weedkiller do?
Disrupt the growth of certain plants only
What is a hormone?
A chemical messenger
How do hormones travel around the body?
In the bloodstream
What produces hormones?
Glands ( endocrine glands if you are showing off!)
Is a baby girl born with all her eggs?
Yes but they are not mature
When does a girl start to mature eggs?
At puberty
Where are auxins produced?
shoot tips and roots
A root grows towards gravity. Where does auxin accumulate?
On the lower side
If there was water near would a root grow towards it or away from it?
Towards it
The “ Pill” contains which hormone
Oestrogen. ( or sometimes another hormone called progesterone)
What causes uneven cell elongation in plant tips?
Uneven distribution of auxin
What is this showing?
IVF
What is the photo showing?
Positive phototropism
ie growing towards light
