Bio paper 2
Homeostasis
Inheritance
Variation/ Evolution
Ecology
The eye:
- ciliary muscles contract
- suspensory ligaments loosen
- lens thicken
- closer vision
................................. - ciliary muscles loosen
- suspensory ligaments contract
- lens thins
- further vision
The brain:
cerebral cortex--> memory, language
medulla--> heart rate, breathing rate
cerebellum--> balance
difficult to treat as it is protected by the skull and easy to damage
MRI scanning, electrical stimulation,
eutoprofication
diploid
haploid
caused by runoff of excess fertilizers from farmers fields
RP reaction time:
- person 1 sits on a stool and places their dominant arm over a table
- person 2 holds the ruler vertically between person 1's thumb and first finger
- person 2 drops the ruler at a random time
- person 1 catches the ruler
- person 2 records the length on the ruler
- short rest and repeat, calculating a mean
- repeat with person 2 and compare results
Thermoregulation:
- sweat glands release sweat onto the surface of the skin
- sweat evaporates
- this takes energy from the body, cooling it down
Vasodilation:
- blood vessels dilate
- more blood flows through the capillaries
- more heat transfer out the blood
Reflex arc:
- stimulus
- receptor
- coordinator
- effector
- response
- sensory, relay, motor neurones
Food security
changing diets mean scarce food resources are transported to be sold to other areas from areas which need them
new pests and pathogens that attack crops
climate change making farming more difficult
Population
increased costs of farming
Climate change
Intensive farming
more efficient
quality control easier
high yield
costly additives
risk of antibiotic resistance
c
onsidered unethical
Oranic farming
nervous system vs endocrine system:
Nervous:
- quick, short lived, neurones
Endocrine:
- bloodstream, longer lasting, slower
Expensive
Reduces biodiversity
petter products
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The kidneys:
if overhydrated:
- pituitary gland stops releasing ADH
- more urine produced
- less water reabsorbed
if dehydration occurs:
- ADH released
- ADH travels to kidneys
- increased permeability of kidney tubules
- less urine produced
- pituitary gland stops releasing ADH
Dialysis:
- blood passes over a semi permeable membrane (allows ions and water to pass through but not proteins as too big)
- urea diffuses into dialysis fluid
Advantages:
- dialysis machines in good supply
Disadvantages:
- punctures skin
- expensive
- inconvenient
Plant responses RP:
- cotton wool in three petri dishes with equal volumes of water
- place 10 seeds in each dish
- allow to germinate
- make sure number of seeds is the same
- measure height of each seedling with a ruler
- place in sunlight/ darkness/ partial light
- one in darkness grows longest
to investigate gravitropism:
- place dish on side
- auxin inhibits cell growth in roots
Menstrual cycle:
FSH- matures egg
LH- begins ovulation
Progesterone
oestrogen
Protein synthesis:
Transcription:
- DNA copied (RNA)
- mRNA passes out the nucelus
Translocation: - mRNA attaches to a ribosome
- amino acids brought to the ribosomes on tRNA
- tRNA joins amino acids together in the correct order
Mutation:
-change to a base= mutation
-caused by different bases encoding for the same amino acid
- active site no longer attaches to substrate
- could lead to cancer on uncontrollable mitosis
genotype- alleles present
phenotype- characteristic
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