Biology Unit one
- Created by: Madisonmck
- Created on: 05-04-15 14:21
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- Biology unit 1
- Diet and metabolic rate
- A balanced diet.
- Carbohydrates release energy
- Fat keeps you warm and releases energy
- protein is used for growth, cell repair and cell replacement
- Fibre keeps everything running smoothly in your digestive system
- Vitamins and minerals keep your skin, bones, blood and everything generally healthy
- Factors affecting health
- Obesity, eating too much leading to excess carbohydrates and fats and lack of exercise
- Malnourishment, can lead to slow growth, fatigue, poor resistance and irregular periods
- Not getting enough exercise. Doing exercise increases the amount of energy used and decreases the amount stored as fat
- Inherited factors which effect their metabolic rate.
- A balanced diet.
- Fighting disease
- Pathogens
- Bacteria: very small living cells which rapidly reproduce in the body. They damage your cells and produce toxins
- Viruses: not cells but they replicate themselves by invading your cells, the cells usually then burst. This makes you feel ill.
- Defences
- Consuming them: White blood cells engulf foreign cells and digest them
- Antibodies are produced: these are proteins which lock onto the certain pathogen, these are produced rapidly
- Producing anti-toxins, these counteract the toxins produced by the invading bacteria
- Vaccinations involve injecting the dead or inactive version of the microorganism, your body them produces antibodies and your memory cells remember the antibodies needed to kill that pathogen.
- drugs
- Some just relieve symptoms eg. painkillers
- Bacteria can become resistant to antibiotics, they can mutate
- Pathogens
- The nervous system
- Sense organs
- Eyes, light receptors
- Ears, sound receptors
- Nose, smell receptor
- Skin, touch receptor
- The reflex arc
- STIMULUS -> RECEPTOR -> SENSORY NEURON -> RELAY NEURON -> MOTOR NEURON -> EFFECTOR -> RESPONSE
- Synapses
- connect neurons, the nerve signal is transferred by chemicals which diffuse across
- Sense organs
- Hormones
- Chemical messengers sent in the blood
- Plant hormones
- auxin is a plant growth hormone in response to:
- light (phototropism), when the shoot tip is exposed to light, more auxin accumulates on the shaded side
- Gravity (geotrophism) shoots grow away from gravity
- Roots grow towards gravity
- Moisture, roots grow towards moisture,more moisture inhibits growth making it bend towards the moisture
- auxin is a plant growth hormone in response to:
- The menstrual cycle
- Hormones involved
- FSH: produced by the pituitary gland, causes the egg to mature and stimulates the ovaries to produce oestrogen
- Oestrogen: produced by the ovaries, causes the pituitary to produce LH, inhibits further release of FSH
- LH: produced by the pituitaryy gland stimulates the release of an egg
- The four stages
- Stage 1: the bleeding starts, uterus lining breaks down
- Stage 2: lining of the uterus build up again
- Stage 3: an egg is released
- Stage 4: the wall is maintained
- Hormones involved
- Homeostasis
- the maintenance of a constant internal enviroment
- Ion content, water content, sugar content and temperature
- Drugs
- change your body chemistry
- Performance enhancing
- can cause high blood pressure
- some are illegal whilst others arent
- medicinal drugs
- testing: tested on human cells in the lab, then on live animals, then human volunteers
- recreational drugs
- legal and illegal
- put into categories such as class A, B and C
- some legal drugs have a bigger impact such as nicotine
- Adaptations
- desert animals have adapted to save water and keep cool
- Arctic animals have adapted to reduce heat loss
- desert plant have adapted to having little water
- some animals and plants are adapted to deter predators
- Extremophiles are micro-organisms that can live in extreme conditions
- Competition and Environmental change
- Plants compete for light, space, water and minerals
- animals compete for territory, food, water and mates
- enviromental changes are effected by living and non living factors
- living
- infectious diseases
- number of predators
- number of prey and food sources
- number of competators
- non living
- change in average temperature
- change in average rainfall
- change in level of air and water pollution
- living
- measuring environmental change
- indicator species
- satellites
- rain gauges
- energy transfer and decay
- most biomass and energy is lost through food chains via respiration etc
- elements are cycled back when they decay
- the carbon cycle
- powered by photosynthesis
- some CO2 is returned to the atmosphere via respiration
- fossil fuels burnt and put back into the air
- Variation
- Characterists due to both the genes and environment
- genes, chromosomes and DNA
- inside cells theres a nucleus which contains 23 pairs of chromosomes
- chromosomes carry genes
- DNA is coiled up to form the arms of chromosomes
- Reproduction
- sexual reproduction involves the fusion of a female and male gamete, there are two parents
- Asexual reproduction involves one parent, the offspring are genetically identical to the parent
- Cloning
- plants
- Tissue culture
- take a few plant cells, put in a growth medium with hormones
- cuttings
- take a cutting then plant it
- Tissue culture
- animals
- embryo transplant
- sperm cells and egg taken from parents, embryo is split and put into many mothers
- adult cell cloning
- egg cell taken, nucleus removed and nucleus from body cell is inserted, then given an electric shock then implanted
- embryo transplant
- plants
- Genetic engineering
- GM crops
- genes modified to suit what the farmer wants
- GM crops
- Evolution
- Charles Darwin Natural selection
- the better adapted survived and passed genes on
- Lamarck thought that the characteristic most used would be passed down
- Charles Darwin Natural selection
- Diet and metabolic rate
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