paper 1 biology
b1
Eukaryotic cells have these functions
cytoplasm
cell membrane
Genetic material stored within a nucleus
examples include plant and animal cells
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B3
B2
Prokaryotic cells
The genetic material is not stored within the nucleus
Bacteria cells
Specialised cells
Blood cells
Have a large surface area
Have no nucleus
ciliated epithelial cell
Have tiny hairs to sweep mucus
sperm
Mitosis cell growth
steps of mitosis
- copy dna
2.divide in two
what is it used for?
Growth and repair of cells
asexual reproduction
all cells formed in this way are identical
steam cells
are unspecified cells that can be fund in bone marrow and embryos and can be used to trek particular conditions.
a group of cells makes a tissue
a group of tissues makes an organ
a group of organs makes up an organ system
a group of organs makes up an organism
enzymes
Enzyme's are biological catalyst's used to speed up chemical reactions
They are made up of long chains of amino acids
The enzymes only fit substrates of a specific shape within them like a lock and key.
The active site can be natured by high tempertures and specific phs
Amylaze breaks starch down into glucose
lipase breaks down lipids into fatty acids and glycerol
protease breaks proteins down into amino acids
found in the pancreas, mouth and small intestine
found in pancreas and small intestine
found in the stomach,small intestine and pancrease
Bile
Is made in the liver and stored in the gall bladder
Its role is to neutralise stomach acid and break down fats
The lungs diffuse oxygen in and carbon dioxide out
The alveoli helps this by
being only one cell thick
moist lining
massive surface area
how is blood carried around the body?
Arteries
Capillaries
Veins
Carry blood under high pressure generated by the heart
Thick outer wall
small lumen
Thick layer of muscle and elastic fibres
allows food and oxygen to diffuse to the cells and waste to diffuse out.
connect veins and arteries
wall are only on cell thick
Have very small lumen
carry low pressure blood back to the heart
Have thin layer of muscle and elastic fibres
have no valves
have valves to prevent the backflow of blood
Have large lumen
blood
white blood cells
help the body fight infection
red blood cells
carry oxygen around the body
adaptations
large surface area
no nucleus
Plasma
Platelets
straw coloured liquid which transports co2 and glucose, removing waste from the kidneys
platnts
Parts of a leaf
Upper epidermis
guard cells
stomata
spongy mesphyil
Has a waxy cuticle in order to act as waterproofing
phloem
xylem
Transpiration
the steps of transpiration:
things that effect the rate of transpiration
Transparent in order to let light in for photosynthesis
hummidity
temperature
light
wind
reduces rate of transpiration
the higher the light intensity the quicker transpiration takes place
plants transpire at a quicker rate if the temperature is higher as the water evaporates at a quicker rate
reduces the rate of transpiration
B4
Required practicals
water evaporates through the stomata
water passes back into the leaf through the xylem vessles
water is pulled upwards through the xylem tissue
this is replaced by water entering the root tissue
water enters root hair cells by osmosis to eventually replace the water lost in respiration
photosythesis
photosynthesis occurs inside the chloroplasts and uses the pigment chlorophyll. The pigment absorbs light energy which is converted into chemical energy and stored as glucose
equations
6CO2 + 6H20>>>C6H12O6+6O2
Carbon dioxide+ water.>>>Glucose + oxygen
The glucose created is stored as energy once converted to starch.Starch is used for:food production,respiration,oils and fats,seeds,energy and to make cellullose
transports water around the plant and acts as support
has no cytoplasm or end walls allowing water to flow freely
Palisade cells
contain lots of chloroplasts in order to perform photosynthesis
transport glucose and sugars
stomats are tiny pores which allow gas exchange to take place the guard cells control them opening and closing
Bacteria
fungi
virus
protisists
small living cells which produce toxins
produce spores and penetrate human skin
live and reproduce in human cells creating cell damage
eukoryotic cells that spread through a vector
examples of a virus
enzymes in industry
trysin is used in baby food to predigest it
protease used in washing powder to break down fatty stains
hiv
measles
spread through sexual contact or exchange of bodily fluids
unless controlled with antivirals the virus attacks the bodys immune system and can lead to risk of more infections or cancer.
is caught by inhaling droplets from sneeze's or coughs
symptoms are fever and red rash
could be fatal most children are vaccinated against it
TMV
widespread plant virus causes a mosaic discolouration and prevents photosynthesis taking place in plants
example of bacterial diseases
gonorea
salmonella
is spread through unhygienic food preparation
symptoms include vomiting,fever,cramps and diarhoea
is an std the spread of which can be controlled by the use of condoms
it creates thick yellow discharge from the penis or vagina and causes pain when urinating
malaria
rose black spot
black spots appear on leaves of a plant which then drop early reducing the amount of photosynthesis performed by a plant
spread by wind and rain and treated with fungisides
causes recurring fever and can be fatal
the vector is mosquittos and to prevent the spread you have to minimize the chance of being bittern
human defence against microbes
hairs and mucus in the nose trap particles that could contain patheogen
the skin acts as a waterproof barrier
the stomach contains hydrochloric acid which kills bacteria
the breathing organs have hairs and produce mucus to cover the linning of these organs in order to prevent patheogens entering
white blood cells
If a microbe enters the body it needs to be neutralized or killed and this is done by the white blood cell
They eat the microbe
the produce antibodies to neutralize the microbe
they produce antitoxins to neutralize the poisons produced by the microbes
the steps of the production of antibodies
step 1:the white blood cell "sees" the patheogen
step 2 :the cell produces antibodies to fit the patheogen
step 3:the antibodies fit onto the patheogen and cause them to clump
step 4:the patheogens are then eatern by white blood cells
vaccination
work by injecting a small quantity of a dead or inactive pathogen into the body. The body is then "tricked" into producing antibodies for the real thing. The body then "remembers" the microbe by producing memory cells if coming back in contact with the microbe.
Aerobic respiration
all living organisms have to move , grow, reproduce and each of these processes requires energy. The way in which are bodies produce energy is through respiration.
equations of aerobic respiration
glucose + oxygen.>>water+ carbon dioxide+energy
C6H126O2>>>>6H2O+6CO2+energy
uses of energy
to build up sugars
to build up body proteins
to maintain a constant body temperature
to build up sugar and nitrates in plants
anaerobic respiration
unlike aerobic respiration,anerobic repiration is when energy is provided without needing oxygen
this happens when the body doesn't produce enough oxygen at a quick enough rate for aerobic respiration
it is quicker however only produce 1/20 of the amount aerobic respiration makes
glucose>>>lactic acid+small amount of energy
Lacid acid is produced in anaerobic respiration which causes muscle fatigue
this debt needs to be repaid by deep breathing
investigating amylase solution
dependent variable: what is being measured
independent variable:what is bening changed
light and photosythesis
indepent
dependednt
summary
investigating osmosis
food test
independent
dependent
summary
independent
dependent
summary
indpendent
dependent
summary
using a light microscope
dependent
summary
independent
the different specimens
what cells look like and how big are they (average cell size)
specimens are cut thinly and placed on the microscope the average cell size is found by the field of view / number of cells
effect of salt or sugar solutions on osmosis
the solution the potatoes are kept in
measure the weight of the potato before and after being kept in salt or sugar solution to highlight the amount of water particles which have entered the potato by osomsis
the effect of light intensity on photodythesis-the amount of bubbles produced
the distance between the pound weed and the light
the amount of bubbles produced by pondweed at different distance from a light source is measured to calculate the effect of light intensity on photosynthesis
if their is starch,lipids,proteins or sugar in foods
the foods and chemicals used to test for different components
test for starch
if starch is present iodine turns blue black
test for protein
biurells solution turns purple if protein is present
test for sugar
benedicts solution turns brick red
test for lipids
ethanol turns cloud if lipids are present
if starch is present iodine goes black
the ph levels
the rate of reaction at different ph levels
the effect of tempersature on rate of reaction
the temperature
if starch is not present iodine goes orange
investigating reaction time
measuring population size
dependent
independent
the destraction eg music,alchol,talking
the effect of a variable on the reaction time
independent
dependent
the areas investigated
how different species are distributed
exchange tissue
all have large surface area
all have a short diffusion pathway
examples on the silibace
alveoli
root hair cell
small intestine
all have a high concentration gradient
gills
only one cell thick to create a short diffusion pathway
folded in order to have large surface area
neurone
muscle cell
job is to fertalise the egg
has enzymes in the head to break through the egg
streamline shape
tail in order to swim
many mitercondria to give the sperm energy
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has many connections to form synapses with many other neurons
in order to give the person or animal better co-ordination
long to cover more distance
many mitercondria
lots of ribisomes
job is to contract
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45 percent red blood cells
55 percent plasma
1 percent white blood cells and platelets