Biology B1 Notes X

Biology B1 Notes for AQA

HideShow resource information
Preview of Biology B1 Notes X

First 142 words of the document:

Biology B1 Notes
B1a
CO-ORDINATION AND CONTROL
The nervous system enables you to react to your surroundings and co-ordinate
your behaviour.
The nervous system carries electrical signals (impulses) which travel fast.
Any changes (stimuli) are picked up by receptors.
The information (electrical signals) passes along the neurones.
The information reaches the Central Nervous System (CNS). It is made up of
the brain and spinal cord.
The body co-ordinates the information and sends impulses from the CNS to the
rest of the body.
Automatic responses are called reflexes.
Synapses are between the neurones. It is chemical.
The menstrual cycle is controlled by hormones. It happens every 28 days.
After 14 days the egg starts maturing, and is released from the ovary. This is
known as ovulation.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Oral contraceptives contain Oestrogen, which stop the production of FSH, so
that the eggs mature.
Fertility drugs contain FSH, to make the egg mature.
When your fallopian tubes are damaged, the eggs can't reach the womb, so the
eggs are removed and fertilised outside the body. Then the developing embryos
are put back in the uterus of the mother. This is called IVF.
Homeostasis is keeping the conditions inside your body as constant as possible.…read more

Page 3

Preview of page 3

Here's a taster:

A drug is a substance which alters the way in which your body works. It can
affect your mind, body or both.
Some drugs make you addicted to them. When addicts try to stop using drugs,
they get WITHDRAWAL SYMPTOMS like aches, pains, sweating, shaking,
headaches and cravings for the drug.
Cannabis causes psychological problems.
Cocaine and heroin are very addictive and cause serious health problems.
Caffeine, nicotine and cocaine speed up the activity of your brain. They make
you feel more alert and energetic.…read more

Page 4

Preview of page 4

Here's a taster:

If you cut your skin, platelets form a clot which dries into a scab. The scab
prevents pathogens from entering.
White blood cells ingest (eat) pathogens, produce antibodies (these target
particular virus or bacteria and destroy them) and produce antitoxins (they can
counteract the toxins released by pathogens ­ neutralise)
Antibiotics can't cure viruses because viruses reproduce inside living cells, so it
is difficult to create a drug which can kill the virus, without damaging the cells
in your body.…read more

Page 5

Preview of page 5

Here's a taster:

Plants use the wind or mini-explosions to spread their seeds.
VARIATION
Inherited characteristics are characteristics passed in to you from your parents.
The resemblance to your parents is in the genetic information passed on to you
in the sex cells (gametes)
Inside the nucleus there are thread like structures called chromosomes. These
chromosomes are made up of DNA. This is where the genetic information is
stored.
DNA is a long molecule made up of two strands which are twisted together to
make a spiral.…read more

Page 6

Preview of page 6

Here's a taster:

Fusion Cell Cloning:
Adult cell cloning ­ You fuse the nucleus of one cell with the empty egg of
another animal. Then you place the embryo in a third animal. It develops there
and is born.
Genetic engineering/modification is used to change an organism and give it
new characteristics which we want to see.
In genetic engineering the DNA from one organism is transferred to the
genetic material of a completely different organism. E.g.…read more

Page 7

Preview of page 7

Here's a taster:

People want to manipulate the genes of their
future children.
EVOLUTION
Fossil fuels provide us with evidence of how much or how little different
organisms have changed.
The theory of evolution tells us that all the species of living things alive have
evolved from simple life forms.
Lamarck's theory was that the characteristics that the parent acquired were
passed on to the children. E.g. if the parent did lots of swimming and developed
broad shoulders, then the children will have broad shoulders.…read more

Page 8

Preview of page 8

Here's a taster:

More rice fields and cattle have increased methane levels.
Improving your quality of life without compromising future generations is
known as sustainable development.
You can help sustainable development by recycling, making our homes energy
efficient and avoid using cars when possible.
Brown field sites are towns and cities. Green field sites are the countryside
which has never been built on.
Sites of Special Scientific Interest (SSI) are not allowed to be built on.…read more

Comments

aun

good thank 

Similar Biology resources:

See all Biology resources »See all resources »