Pages in this set

Page 1

Preview of page 1
Biology 1a ­ Human Biology
The Nervous System
A stimulus is a change in your environment which you may need to react to.
Eyes ­ light receptors
Ears ­ sound and `balance' receptors
Nose ­ smell receptors
Tongue ­ taste receptors
Skin ­ sensitive to touch, pressure and temperature change…

Page 2

Preview of page 2
o act for a very short time
o act on a very precise area
o Slower message
o Act for a long time
o Act in a more general way

The Menstrual Cycle
o Produced by the pituitary gland
o Causes an egg to mature
o Stimulates the…

Page 3

Preview of page 3
Hot day or exercising ­ sweat a lot, so produce less urine which will be
more concentrated. Also lose more water through breath.
o Sugar content ­ foods containing carbohydrate puts glucose into the blood from
o Temperature ­ enzymes within the human body work best at about 37°C…

Page 4

Preview of page 4
Thalidomide ­ was a sleeping pill (tested for that), but later was found to be effective in
relieving morning sickness in pregnant women (unfortunately wasn't tested for this) ­
caused stunted growth of foetus's arm & legs. Now used to treat leprosy, AIDS & certain

Alcohol & Tobacco

Page 5

Preview of page 5
Looked at whether cannabis causes brain damage & mental health problems
or leads to further drug taking.
Results are open to different interpretations

Fighting Disease
2 main types of pathogen
o Bacteria:
Very small living cells, which can reproduce rapidly inside your body.
Make you feel ill by:
Damaging your…

Page 6

Preview of page 6
If antibiotics deal with an infection & some of the bacteria are killed, those which survive
may be resistant to the antibiotics & go on to flourish. ­ Which leaves you with an
antibioticresistant strain of bacteria.
E.g. MRSA (methicillinresistant Staphylococcus Aureus) ­ it's resistant to the antibiotic


Page 7

Preview of page 7
1. Competition ­ organisms compete with other species for the same resources. ­
can affect the location, size & distribution of populations in the wild.
a) Plants compete with each other for light, water & nutrients from the soil
b) Animals ­ compete with each other for space, food, water…

Page 8

Preview of page 8
Egg & sperm fuses together to form a cell with the full number of chromosomes.

Plants can be cloned by 1 of the following:
o Cutting ­ gardeners can take cuttings from good plants & plant them to produce
identical copies of the parent plant. ­ can be produced…

Page 9

Preview of page 9
Theory of evolution = life on Earth began as simple organisms from which all the more
complex organisms evolved.
Species become extinct for 3 main reasons:
1. Environment changes too quickly ­ e.g. destruction of habitat
2. A new predator or disease kills them all ­ e.g. humans hunting them…

Page 10

Preview of page 10
Several different gases in the atmosphere which help keep the heat in, called greenhouse
gases. Main ones are:
o Carbon dioxide ­ humans release this all the time as part of our everyday lives ­
car exhausts, industrial processes, as we burn fossil fuels, deforestation etc.
o Methane ­ rice…


No comments have yet been made

Similar Biology resources:

See all Biology resources »