Biology Flashcards
Hormones related in a girls menstrual cycle
1.(FSH) Follicle stimulating hormone causes egg in ovary to mature the eggs grow surrounded by cells called the follicle THIS IS SECRETED BY THE PITUARY GLAND
2.Oestrogen stimulates to build up the uterus lining and PROGESTERONE maintains it
3.Luteinising Hormone (LH) stimullates release of the egg at ovulation
4.Progesterone maintains the building of the uterus lining
On average how long is one full menstrual cycle
28 days.
Day 1 to about day 6 ( Menstruation)
What happens
Uterus lining comes away from the wall and exits the vagina as blood
Day 7 to about 13 what happens
Around day 7 blood flow stops
The lining of the uterus starts to build again
Also at this time FSH causes an egg to start to mature in one of the ovaries
On day 14 what happens
On the 14 day which is the middle of the cycle
LH is produced and causes an egg to be released by am ovary into the oviduct
What happens in day 14 to 17
The egg lasts up to 3 days after being released by the ovary
During this time the egg travels down the oviduct and into the uterus hoping to be fertilised
Day 18 28 what happens
If the egg is not fertilised in the time it lasts there then Oestrogen and Progesterone levels drop and the lining of the uterus begins to break down
Female Fertility Facts
The ovaries of a baby girl will comtain the eggs she will ever gave
They then keep mature and release for an average of 35-40 tears except when pregnant
When the eggs are all gone it is menopause
When a woman is near menopause she is less fertile
The main events of the menstruation cycle
1) Menstruation Uterus lining breaks down blood and cells are lost
2) Proliferation repair of uterus lining
3) Ovulation release of an egg from ovary
When FSH is released what happens
FSH is released and tells the egg to start developing
Oestrogen is released from ovaries
Oestrogen levels increasing making the uterus lining FSH is prevented and LH is released and stimulates ovulation( the egg is sent to uterus through oviduct
After day 14 what happens
Fertilisation/No fertilisation?
If it gets fertilised pregnancy occurs
Progesterone levels stay high
If not fertilised progesterone levels drop
What is tropism
A tropism is a growth movement of a part of a plant in response to a stimulus
Response to light (tropism)
Photo tropism
Photo- means light
Response to gravity (Tropism)
Response to gravity is called geotropism.
Response to water (Tropism)
Response to water is called hydrotropism
How do shoots and roots repsond differnetly
Shoots and roots respond differently:
• Shoots grow towards light and against the force of gravity
• Roots grow towards moisture and in the direction of the force of gravity.
Formula for magunification
Magnification= image size / object size
Define image in microscopy
The image we see through Microscope
Define objects in microkscopy
The real object or sample you’re looking at
Define magnification in microscopy
How many times larger the image is than the object
Define resolution in microscopy
It is a measure of the microscopes ability to distinguish between two points which are close together on an object
Light microscope details five in total
Easy to use
Relatively cheap
Rely on light
The resolution is limited to 0.2 µm
Not good enough to study cellular structures
Electron microscope details five details
Very expensive
Hard to use only used by scientists in laboratories
Use electrons instead of light
Max resolution is 0.1 µm
You can use them to study subcellular structures
4 factors of affecting the speed of bacterial growth
Temperature
Nutrient availability
Moisture
Oxygen
