Things U Got Wring Gcse Mindmap Flashcards
How is urea produced
The breakdown of excess amino acids in the liver
How can carbon dioxide be toxic if it builds up inside a human
Can dissolve in water
Making fluid acidic
This lowers the PH of enzymes, reducing their activity
Why will water be lost from cells if too many toxic fluids build up in the body
-because the body fluid will be concentrated
-therefore the water potential inside cells will be higher than outside
-so water will be lost by osmosis from high water potential to low water potential
-preventing the cells from carrying out reactions
What is the gland located right on top of the kidney
The adrenal gland
The nephron is located in which part of the kidney.
And then which parts of the nephron are in which
In both the cortex and medulla.
The proximal consulted tubule and distal consulted tubule are inside the cortex
The loop of henle and collecting duct are inside the medulla
Why does blood that enters the glomerulus come in at a high pressure
Because the blood that enters the renal artery comes from the aorta
And because the capillaries are narrow as they enter the glomerulus
Which molecules are not filtered into the glomerular filtrate
Proteins and red blood cells
Give 4 organs of excretion, and what they excrete
1)skin- water and excess ions
2)lungs-co2 and water
3)liver-breaks down amino acids to form urea which is toxic
4)kidneys-metabolic waste substances, like, urea, water, excess ions
What is sweat made up of
Water and excess mineral ions eg sodium
Why is homeostasis
The maintenance of a constant internal environment, despite external change
Three difference between nervous and hormonal responses
Nervous coordinated by nerves, travel by electric impulses
Hormonal coordinated by glands, travel through hormones in the blood
Nervous much quicker
Nervous effects much more short lasting
What is the role of the mitochondria in aerobic respiration
They perform aerobic respiration, by converting glucose into ATP
Name 8 substances that the glucose formed from photosynthesis can make
Energy in the form atp (released when the glucose form photosynthesis used for repsiration in mitochondria)
Cellulose (made with energy from respiration, which makes bonds between glucose monomers)
Starch
Lipids (which are stored in seeds)
Amino acids, then proteins or dna (made when glucose combines with nitrate ions)
Chlorophyll (made when glucose combines with magnesium ions)
Fructose
Sucrose (used for transport)
How can cellulose be made from photosynthesis.
And state it’s function
Photosynthesis produces glucose
Glusoce is then used by mitochondria in aerobic respiration to produce energy in form of ATP
This energy makes bonds between glucose monomers to make cellulose
Used to produce cell walls, providing them with strength
How can proteins be made from photosynthesis
Glucose produced from photosynthesis
Combines with a nitrate ion
This produces amino acids
Which can then form proteins
What two ways can glucose be stored in inside a plant
Inside starch
Inside lipids (which are stored in seeds, which can also make cell membranes)
Balanced symbol equation for photosynthesis
6CO2 + 6H2O —-) C6H12O6 + 6O
Limiting reactant meaning
Component of the reaction in shortest supply, so that it limits the rate of reaction from increasing
Function of the spongy mesophyl
Main surface of gas exchange, so Contains large air spaces to increase surface area to volume ratio for diffusion
Function of the upper epidermis
Thin and translucent layer to allow light to enter through onto the palisade mesophyl layed
State the two layers of the leaf underneath the upper epidermis
Palisade mesophyl
Spongy mesophyl
functions of the stomata in photosynthesis
Where gas exchange occurs,allowing co2 to enter and oxygen to leave through diffusion
Allows for the evaporation of water for transpiration
Give 6 adaptations of a leaf for photosynthesis
-thin and translucent upper epidermis to allow maximum light to enter for photosynthesis
-contains tightly packed palisade cells which contain chlorophyll to absorb light energ for photosynthesis
-thin for shirt diffusion distance of co2 to enter
-flat for large surface area for max light to enter, and max co2 to enter by diffusion
-network of veins, to transport water to cells for photosynthesis
-stomata, to allow co2 to diffuse in and oxygen to diffuse out
State the functions of 4 mineral ions and what their deficiencies look like
-nitrates— needed to make amino acids for proteins for cell growth—stunted growth + yellowed leaves
-phosphates— needed to make dna for cell membranes—purple leaves
-potassium— allow enzymes to carry out reactions such as photo + resp—-yellows leaves + dead spots
-magnesium— needed to make chlorhydrique for photosynthesis—- yellowed leaves
How can you see that oxygen is produced during photosynthesis
-use aquatic plant such as pondweed
-submerge underneath water
-bubbles with form to demonstrate oxygen is formed
-to prove, it will relight a glowing splint
Why could you not test a leave for glucose, to demonstrate it has photosynthesized
Because once has glucose has been produced, it quickly is transported around the plant, or then as a storage in the form of starch
Explain the main steps of how you test a leaf for starch
1)set up a tripod and gauze, and heat a beaker of water
2)place the life inside a boiling tube to kill it and prevent chemical reactions from happening, so that outer layer is removed and iodine can later be absorbed
3)after 30 secs remove and place inside a test tube of ethanol, to remove chlorophyll so that the colour odpf iodine can be seen
4)rinse with cold water to soften
5)lay out on a soft tile and add iodine solution
Explain how you can investigate the effect of carbon dioxide on photosynthesis
1)take a leaf and de starch by placing in cupboard for 24 hours, to ensure all r meaning starch is used up
2)place inside a bell jar with all the suitable conditions for photosynthesis eg light
3)add sodium hydroxide to the bell jar to absorb all the co2
4)then follow the steps to test the leaf for starch (boiling water, ethanol, cold water, iodine), shoukd turn yellow brown because no starch present
Explain how you can investigate the effect of light intensity of photosynthesis
1)de starch half a leaf by wrapping in aluminum foil for 48 hours
2)expose the leaf to light
3)follow the steps to test the leaf for starch (boiling waters, ethanol, cold water, iodine)
4)part exposed to light will turn blue black bc contains starch, part wrapped up will remain yellow brown
Explain how you can investigate the effect of chlorophyll on photosynthesis
1)take a variegated leaf
2)perform the test for starch on it
3)green part will turn blue black, yellow part will remain yellow brown after iodine is placed on it
Photosynthesis is a … reaction and repsiration is a…. Reaction
Endothermic
Exothermic
What two factors can be measured to investigate respiration in seeds
Production of co2, (can use hydrogen carbonate indicator)
Production of heat, (use a thermometer)
….. can be used to remove carbon dioxide from the surroundings
…..can be used to measure the levels of carbon dioxide in the surroundings
Sodium hydroxide
Hydrogen carbonate indicator
State the colors that hydrogen carbonate indicator turns in different levels of carbon dioxide
Yellow- high levels
Orange- atmospheric levels
Purple- low levels
Give 6 adaptations of a leaf for gas exchange
-FLAT for large surface area to volume ratio for diffusion
-thin to provide short distance for diffusion
-contain many stoma to maintain steep conc GRADIENT for diffusion
-contain many air spaces to increase surface area to volume for diffusion, and to allow EASIED MOVEMENT of gases
-close contact between air spaces and cells so that more efficient gas exchange
-moist air to allow gases to dissolve and so they can MIVE EASIER so for more effective gas exchange
Why do leaves have large air spaces
To provide large surface area to volume for diffusion of gases
And to allow gases to move more easily
Explain what happens to the stomata in low light levels
Water moves out of the guard cells through osmosis
So they become flaccid,
So this prevents any diffusion of gases into or out of the stomata
Explain what happens to the stomata in high light levels
Water moves into the guard cells through osmosis
Causing them to be turgid
This means that gases can diffuse into or out of the stomata for gas exchange
Why do stomata close during the….
Night
Because they are not photosynthesizing and so respiration is being favoured instead
Therefore they are producing water as a byproduct, so the stomata close to prevent evaporation of water through transpiration
Give a more detailed defintion of transpiration
The evaporation of water from the spongy mesophyl, followed by the diffusion of water vapour through the air spaces, out of the stomata into the air
How does wind speed affect transpiration
High wind speed, increases transpiration
This is because it removes the excess water vapour from the surface of the leaf
Therfore steeper conc gradient of water vapour between leaf and the air
So water will thus DIFFUSE out at a higher rate
(Don’t say evaporate, bc the water has already evaporated into water vapour in the inside of the leaf)
Explain how the transportation stream works
Water evaporates into water vapour inside the spongy mesophyl layer
This diffuses through the air spaces, out of the stomata
To replace the water that has been lost, transpiration creates a “pull”
And So because water molecules in the xylem vessel are cohesive ( stick together)
They are pulled up and transported to parts of the leaf
4 functions of transpiration
-Transports mineral ions to the plants by dissolving them in water
-provides water to cells for photosynthesis
-provides water to cells to keep them turgid, to provide support to the plant
-keeps the LEAVES cool, because conversion of water into water vapour removing heat energy
State the route of water into the plant
Enters through root hair cell (osmosis)
Root cortex cell
Xylem vessel
Leaf mesophyl cells
What substances does the phloem transport
Sucrose and amino acids
Describe the structural differences and the movement between phloem and xylem
Xylem consists of dead cells
The end walls are removed to provide a hollow continuous tube
Strengthened by cell walls of lignin
Water can only move up
Phloem consists of living cells
Substances (sucrose and amino acids) move between the end walls through pores/sieve plates
Water can move up or down
Give a limitation of using promoters to measure transpiration
Only gives measurement of how much water has been used, but unknown how much has been used for transpiration, and how much has been used in other processes eg photosynthesis or providing turgor
Give three accuracy things u must do when conducting a bubble photometer experiment to measure rate of transpiration
Cut the stem underwater to prevent air bubbles forming in the xylem
Cut at an angle to increase surface area to volume ratio for water to be absorbed
Dry the leaves first and wait to acclimatize, so that certain that there is no excess water on them
How can you invest Auger effect of humidity on transportation levels
Spray a plastic bag with water and wrap it around the leaf
If you were drawing a graph to show respiration and photosynthesis throughout the day, how would it look
Respiration straight line because constant all day
Photosynthesis peaks at midday and then goes down
Purpose of pleural membranes
Séparâtes lungs from internal features of the thorax, to prevent friction
Which intercostal muscles are involved in ventilation
EXTERNAL
Give the order of substances that are involved in forming blood clots
Saturated fats
Raise cholesterol levels
Increase plaque
Forms blood clots
Give three ways vaccines can be formed
-fragments of the pathogen
-the antigen itself
-pathogen that is unable to reproduce
Why do arteries have muscular walls, and why do they have elastic fibers
Muscular walls, to withstand high pressure
Elastic fibers, to stretch and recoil, to maintain the high pressures
Structure of capillaries
-One cell thick to allow for short diffusion distance for gases
-permeable to allow oxygen and co2 to diffuse in and out
What is a community
Two or more populations of different species living in an area at one time
What is an ecosystem
The interaction of all the abiotic and biotic factors within an area at a single time
Give an equation to use when measuring population size on a field
Mean per quadrat (total number organism counted/ total quadrants used) x total area of field
What is biodiversity
A measure of the range of different species that live in an organism
Give 7 abiotic factors and 4 biotic factors
Abiotic:
-temperature
-light intensity
-wind direction
-soil ph/mineral content
-oxygen levels(eg aquatic plants)
-carbon dioxide levels
-toxic chemicals eg pesticide
Biotic:
-availability of food
-completion for resources
-new predators
-new pathogens
Decomposition meaning
The breakdown of dead organic material into simpler organic compounds by releasing carbon dioxide into the air and is done by organisms such as bacteria
Decomposers defintion
Organisms such as bacteria or fungi that break down dead organic material into simpler organic materials by releasing carbon dioxide into the air for energy, using enzymes
State For pyramids of biomass and pyramids of number,
what each one represents
The size of each bar
Biomass:
Represents the total relative mass of dry material in the trophic level
Size of each bar remains the same
Pyramids of number:
Represents the total number of organisms in the species at each trophic level
Bars can vary in width
Explain how these play a part in the nitrogen cycle:
Lightning
Nitrogen fixing bacteria
Nitrifying bacteria
Decomposers
Denitrifying bacteria
-Lightning fixes atmospheric nitrogen into nitrates, which can be absorbed by plants to make proteins and dna
-nitrogen fixing bacteria is present inside root nodules of legumes, and converts atmospheric nitrogen into ammonia
-nitrifying bacteria converts ammonia, into nitrites, into nitrates
-animals urinate and excrete urea into the soil, and die, so decomposers break down this dead organic material into ammonia
-denitrifying bacteria in water logged soil convert nitrates to atmospheric nitrogen.
Give four ways that carbon can be returned to the soil, and three ways that it can be released into the air
Returned:
-death
-excretion
-fossilation
-photosynthesis
-combustion of fossil fuels
-respiration
-decomposition
What are the two ways that carbon monoxide can be released
Incomplete combustion of fossil fuels
Released through car emissions
Give and explain two effects of acid rain
-acidifies waters and lakes which can kill animals and wildlife sensitive to changes in ph
-can kill trees as it damages the waxy layer on leaves, and it releases toxic substances from the soil, making it difficult for the soil to absorb minerals
State what a green houe gas is
then Give five greenhouse gases and where they are produced from
Greenhouse gas is a gas that absorbs infrared radiation from the sun and then traps it in the earths atmosphere, which leads to the earths temperature to increase.
Carbon dioxide- burning fossi fuels + deforestation
Methane- cattle rearing + rice paddy fields
CFCS- refrigerators
Nitrous oxide- fertilizers and car engines
Water vapour- rivers and lakes
Give four effects of greenhouse gases
-Cause polar ice caps to melt which can lead to rising sea levels
-can lead to cilamate change, causing increases droughts and flood
-can lead to habitat loss and cause species to become extinct, reducing biodiversity
-can lead to increased migration which can cause the spread of disease and pests
Give two substances present in sewage and where they come from
Nitrates, from urea or faeces
Phosphates, from detergent
State three organisms present in water pollution and state what level of pollution they are present in
Stone fly lymph- clean water
Larvae. Slightly polluted
Bloodworms- heavily polluted
Give four consequences of deforestation
Soil erosion
Disturbance to oxygen and carbon dioxide levels
Loss of habitat, extinction and so decrease biodiversity
Less transportation so climate is drier
How does deforestation lead to soil erosion
Roots can no longer hold soil in place
This means that soil can easily be leached by rain water
Leaving infertile soil
Give 5 factors that you can control inside a greenhouse, and give suggestions how to control them
Carbon dioxide levels (paraffin heater)
Water (regular watering)
Temperature (already trapped from sunlight but can use a paraffin heater)
Light intensity (artificial lighting or blinds)
Protection from pests (because enclosed environment)
Protection from weather conditions (eg excessive wind)
Give 3 advantges of pest control and 4 advantages of biological control
Give 5 disadvantages of pest control and 3 disadvantages of biological control
Pest adv; -has an immediate effect
-can kill an entire population
-accessible and cheap
Bio adv;- doesn’t lead to resistance
-doesn’t cause pollution
-can target specific populations
-doesn’t need to be continuously applied
Pest disad: -pests can develop resistance
-can lead to pollution
-can contain persistent chemicals which can build up and lead to bio accumulation
-can kill other unwanted species
-needs to be continuously reapplied
Bio disad;- takes longer to be effective
-cant kill an entire population
-may become a pest itself
Explain how to make yogurt
-sterilize medical equipment to kill harmful pathogens and to prevent chemical contamination
-pasteurize milk to 85-90 to kill other microorganisms to enter which could create competition for resources with lactobacillus and thus halt production
-homogenize the milk to distribute fat globules
-cool to 40-45
-inoculate with lactobacillus and incubate for a few hours and lactobacillus will ferment lactos (milk sugars) into lactic acid
-lactic acid; coagulates the milk, acidifies the ph to prevent other microorganisms from entering, denatures enzymes to form semi solid milk solids, halts the reproduction of yeast
-cool the milk to 5 degrees to halt lactobacillus
-add flavourings and colourings
Give the equation for anaerobic respiration in yeast and then Explain how bread is made
Glucose —-) ethanol + carbon dioxide
1) mix flou, water and yeast together to make dough and the knead the dough
2) the yeast has used up all the available oxygen during aerobic respiration to reproduce, so begins to aerobically respire, by fermenting the flour sugars into ethanol and carbon dioixde
3) placed in the overnight, co2 trapped inside dough causes bread to rise, ethanol evaporates, and Hugh temperatures kill the yeast
Give 7 features of an industrial fermenter and explain what they do
-air in; allows oxygen to enter for aerobic respiration
-air out; gases from fermentation can cause gases to build up so allows them to be released
-nutrient medium; for respiration to produce energy
-paddle stirrers to agitate; agitate to ensure that the contents such as nutrients and oxygen are always in contact with micoorganims. Also distributes heat
-water jacket; to control the temperature for enzymes to function
-tempertaure and ph probes; to monitor temp and ph for enzymes
-steam in:sterilizes to kill unwanted bacteria, so that there is no competition for resources, and this prevents chemical contamination
Give 6 ways to increase yield in fish farming
-to prevent disease, use antibiotics and filter waste to increase survival rate
-feed with high nutrient food and feed frequently to prevent from eating eachother
-control intraspecfifc predation by separating by size and age, control interspecfic by separating by gender
-separate by gender so that they can be selectively bred to increase yield
-keep in cages to reduce energy loss
-keep high oxygen levels in water by filtering and removing waste
Give five advantages of genetically modified plants
-can produce higher yield
-can have higher nutrients value
-can have greater hardiness to extreme weather conditions
-can be disease resistance
-greater attractiveness and taste for consumers
Give three disadvantages of genetically modified plants
-reduces biodiversity
-could cause allergic reactions
-risk of outcrossing, where genes from one gmo plant are transferred to another wild plant, which could reduce the usefulness of the crop, eg if weeds also become herbicide resistant
Give three disadvantages of selectively bred animals
-reduces genetic diversity as there is a reduction in the gene pool
-so if there is an environmental change they are less likely to survive and so become extinct
-so more likely that there are genetic defects present in the offspring
Give examples of;
A plant that has been selectively bred
An animal that has been selectively bred
A plant that has been genetically engineered
Wild brassica, into cauliflower and broccoli
Wolves, into the domestic dog
Golden rice
Explain what golden rice is
Genetically modified crop which produces a chemical to make vitamin a
Prevents blindness in poorer countries
Explain how to make human insulin using genetic modifcation
1) using restriction enzymes, cut out a plasmid from a bacterium cell, which will act as the vector
2)use the same restriction enzymes to take out the human gene for insulin from a human, and leave the corresponding sticky ends open
3)use ligase enzymes to join the human gene and the plasmid together to form a recombinant dna
4)insert his dna inside a bacterium cell and incubate inside a fermentor
5)the bacterium cell will reproduce by binary fission, producing more bacterium with the same recombinant dna and so same gene for insulin
Transgenic meaning
An organism that contains the genetic material of another SPECIES
Explain how micropropogation can be used to make clones of plants
1)select plants with desired characteristics and take an explant from it using a scalpel
2)sterilize to kill harmful bacteria using a disinfectant
3)grow in vitro inside a Petri dish with agar jelly, which should contain nutrients needed for growth, aswell as growth hormones such as auxin
4)cells will divide my mitosis to produce a plant let, which will be genetically identical to the parent plant
5)if more plants are desired to be produced then more explants can be taken
6)can then be taken out and placed in compost in a greenhouse where it can continue to grow with optimum conditions such as temperature or light
Explain how embryonic cloning can occur
1)take the sperm cell from a male and then artificially inseminate a female with the sperm
2)an embryo will form in her uterus, which is taken out of the uterus and divided into separate embryos, all of which are genetically identical
3)these embryos are inserted into surrogate mothers to continue their development until birth
4)the offspring will all be clones of the the first two animals whos sperm and egg cell was sued
Explain how adult cell cloning works (dolly the sheep)
1) take an egg cell from a female cow and remove the nucleus to form an enucleated egg cell
2)take the nucleus out of another animals body cell and insert it into the enucleated egg cell
3)an electric shock is provided to stimulate its growth by mitosis to form an embryo
4)this embryo is inserted into a surrogate mother for its development until birth
5)the offspring will be a clone of the animals who’s body cell nucleus was taken
Give two advantages and three advantages of animal cloning
-can produce genetically identical offspring who have desired characteristics
-can be used to preserve endangered species
-reduced genetic variation means more susceptible to disease
-reduced genetic variation means that more likely to be born with genetic defects
-ethical issues
Describe the structure of carbohydrates and then give examples of different types
Carbohydrates are made up from single monosaccharides which join together to form disaccharides or polysaccharides.
Mono; glucose + fructose
Dissach; maltose + sucrose
Poly; starch, cellulose, glycogen
Give three uses of carbohydrates in the body
-glucose is used in respiration to produce energy for cells in the body in form of atp
-polyyscagraides are sinoluble so can be a good store of energy eg glycogen
-cellulose can be used for dietary roughage
Give the structure of lipids
One glycerol molecule, attached to three fatty acids
Give the functions of;
Calcium
Iron
Vitamin a
Vitamin c
Vitamin d
Dietary fibre
Calcium; needed to make strong teeth and bones
Iron; needed to make haemoglobin in red blood cells, and so help to transport oxygen around body
Vitamin a; needed to make the light sensitive chemical in the retina of the eye for vision
Vitamin c; helps to heal wounds and make connective tissue
Vitamin d; helps in calcium absorption and so helps make strong bones and teeth
Dietary fibre; provides roughage to food to aid with the movement of food through the gut
Give the test to test for lipids
-crush and add to a boiling tube with ethanol and shake
-pour into cold water
-if a cloud white emulsion forms, then lipids are present
Give the test to test for glucose,
Then give the test to test for proteins
1)crush and add to a boiling tube with water in it, and shake
2)add Benedict’s solution
3)heat inside a water bath
4)should turn brick red if glucose is present
1)crush and add to water in a boiling tube, and shake
2)add biuret solution
3)should turn purple
Explain how to investigate the energy content within food
1)measure the mass of the sample of food and mount it to a needle
2)fill a boiling tube with a set amount of water which you have measured and then attach it to a clamp
3)set fire to the food sample with a Bunsen burner and hold it beneath the boiling tube of water
4)keep burning the food until it is completely burnt and then measure the final temperture of water
50 use the equation e=mct where m is mass of warer, c is spec heat cap of water which is 4.2, and t is temperture charge of water
Give an equation you can use to find amount of energy in a food sample,
And then equation to find amount of energy in food sample per gram
-e=mct where m is mass of warer, c is spec heat cap of water which is 4.2, and t is temperture charge of water
-and then e= energy in food/mass of food
Explain the role of the stomach in the digestive system
-food is mechanically digested by the churning of the stomach
-releases hydrochloric acid which kills harmful bacteria and makes the bolts at the optimum temperture for enzyme pepsin to work
-pepsin breaks down proteins into peptides
-sphincter muscles then release the bolus into the duodenum
Explain the role of the duodenum in the digestive system
-pancreas secretes pancreatic juices which contains enzymes such as amalyse and pepsin which continue the breakdown of starch and proteins. It also releases lipase
-bile is released from the gallbladder which emulsifies fats to help the enzyme lipase to digest them, because it increases the surface area to volume ratio
-bile and pancreatic juices also neutralize the bolus to make it at the optimum conditions for enzymes to work best at
Give the enzyme that breaks proteins down and state the substance that it converts it into
Pepsin
Breaks down protein
Into peptides
Where is bile produced and where is it stored
Produced in the liver
Stored in the gallbladder
Explain the role of the ileum in digestion
-its where the absorption of food substances occurs
-happens with the help of villi
-and where assimilation occurs, so where food substances are moved to the parts of the body where they are needed
What is egestion
The removal of undigested waste products
Explain what happens in plant cells when placed in concentrate sugar solution
-water moves out by osmosis
-so vacuole shrinks, and cell membrane shrivels up
-the cell can now be called flaccid or plasmolysed
Explain what happens in plant cells when placed in distilled water
-water moves in by osmosis
-so vacuole becomes larger, and begins to push cel membrane against the cell wall
-this creates a turgor pressure, and so the cell is described as being turgid
Explain what happens in animal cells when placed in a concentrated sugar solution
-water leaves the cell by osmosis
-so the cell shrivels up and become crenated
Explain what happens in animal cells when placed in distilled water
-water movies in by osmosis
-cell continues to gain water until it eventually bursts, because it contains no cell wall to provide turgor pressure
-this process of bursting is called lysis
Function of the cytoplasm
-gel like substances which controls chemical reactions in the cell.
-also contains enzymes to speed up chemical reactions without being used up
Function of cell membrane
Selectively controls what enters and leaves the cell
Cell wall function
Provides strength and support to the cell
Vacuole function
Contains cell sap to keep cell turgid
Give an example of two protoctists
Amoeba- animal like
Chlorelle-plant like
Name the features of a bacteria cell
Flagellum
Slime capsule
Chromosomal dna
Plasmids
Cell membrane
Cell wall made of PEPTIDOGLYCAN
Ribosomes
Mitochondria
Cytoplasm
Name three differences between prokaryotic and eukaryotic cells
-prokaryotic don’t have a nucleus
-prokaryotic dont have any membrane bound organelles
-prokaryotic have a nucleoid
Name the features of a virus cell
Lip envelope
Protein coat
Dna or rna
Name three types of stem cells.
Then give three advantages and three disadvantages of using stem cell
Embryonic. adult. Meristem
Adv; -have the potential to treat a wide variety of diseases
-adult stem cells can repair and replace damaged tissue
-organs developed form a patients own stem cells are less likely to be rejected
Dis:-ethical issues, eg arent embryos potential to be humans
-stem cells cultured in labs have potential to be infected with virus
-stem cells cultured in labs can Develop mutations and become cancerous cells
What causes blood to clot
Platelets
Explain how saprotrophic nutrition occurs
Spore lands on DEAD DECAYING ORGANIC MATERIAL
a network of hyphae called mycelium grows
Secretes digestive enzymes onto it, so that it can perform EXTRACELLULAR DIGESTION
Mould then ABSORBS the digested food
Explain why there is less cloudiness in a test tube of 4 degrees when peas are placed in water. (In terms of fungi)
4 degrees is not an optimum temperature for enzymes,
As there is less kinetic energy, so less frequent collisions, so less enzyme substrate complexes formed
Therefore less fungal growth
And so less aerobic respiration
What are the next three successive layers underneath the waxy cuticle in a plant
Upper epidermis
Palisade mesophyl
Spongy mesophyl
Why is it an advantage to have less stomata in a hot dry area,
And why may it not be an advantage
And advantage Bc,
-means less transportation, so less water loss
-less transpiration so less wilting (transpiration can cause wilting bc water is lost form the plant so less turgid)
A disadvantage bc,
-less transpiration means less mineral ions transported
-less transportation means less of a cooling effect
-less stomata means less co2 uptake, so less photosynthesis
Explain how you can selectively breed animals for an advantageous trait
Select two organisms with advantageous trait and breed together
SELECT OFFSPRING with advantageous trait aswell and breed together
Repeat over generations
So that the ALLELES FOR THE ADVANTAGEOUS TRAIT ARE PASSED ON
How is ammonia converted to nitrates
Nitrifying bacteria convert ammonia to nitrites to nitrates
How are amino acids and proteins made from glucose
Glucose produced from respiration
Binds with nitrate ions
To make amino acids and proteins
Eutrophication occurs on the basis of what organism
Algae
(Not seaweed or anything else)
Through which process is glucose absorbed into the bloodstream in the proximal convoluted tubule
Active transport
Using energy in form atp
Structure if the nephron
Glomerulus
Bowman’s capsule
Proximal convoluted
Loop of henle
Distal convuluted
Collecting duct
Overtime, give two reason why mutations in an organism may increase in a radioactive area
-A longer exposure time means more mutations
-adults who reproduce will pass on mutated genes to offspring
Advantges of a seeds germinating away from the parent plant. Advantges if it germinating near by
-less competition for minerals eg magneiusm
-less completion for light
- has a plant to cross pollinate with
-can grow in same conditions as parent plant did successfully
State three conditions required for termination and their functions. Then state how germination occurs
Water required so that seed can swell, and seed coat can burst releasing the embryo.
Also required to allow enzymes to begin to function for growth
Oxygen required for aerobic respiration
Warm tempertaure for enzymes optimum temperature
Once seed begins germinating, embryo develops and structures called cotyledons develop which provide food reserves such as starch for the plant.
After absorbing water, the seed coat bursts and an embryo is released to begin growing. The plumule becomes the shoot and the radicle becomes the roots
Give two reasons why glucose is absorbed in the nephron
To maintain blood glucose levels
To be used in the body for aerobic respiration
If i eat more protein, how will this affect the amount of glucose reabsorbed,excreted, and filtered through in the nephron
Although more glucose will be filtered through into the nephron
It is always all absorbed, therefore none is excreted
If i eat food high in sodium, how does this affect the amount of water absorbed in the nephron
High in sodium, means less water potential in the blood, so its more concentrated
Osmoreceptros trigger the pituatary gland to release more adh
This makes the collecting duct more permeable
So more water is reabsorbed,
Therefore less is excreted
Where are osmorecpetrs found
In the hypothalamus
1mm equals how many micromètres
1000
Function of water in plants
Transports mineral ions
Provides water for photosynthesis to occur
Keeps plants turgid
Keeps leaves cool through evaporation from leaves
Through which process does the root hair cell absorb water and explain how
Absorbs water through osmosis,
because the root hair cell has a low water potential, due to the presence of dissolved minerals in its cytoplasm.
Therefore water moves in from a high water potential to a low water potential.
Root hair cell had a large surface area to allow this to happen
Why should you not overwater the plant soil around a plant
Because the plant roots will be able to absorb less oxygen,
Therefore favoring anaerobic respiration
Anaerobic repsiration produces less atp,
Therefore less mineral ions can be absorbed etc
For the four main parts of the nitrogen cycle, explain what is converted to what in each part
Lightning; atmospheric nitrogen—nitrogen oxides which dissolve in soil—nitrates
Denitrifaction; nitrates-nitrogen
Nitrogen fixing; nitrogen-ammonia-ammonium ions in solution in soil
Decomposition;nitrogen compounds eg urea- ammonia- ammonium ions
Nitrification;ammonium ions in soil-nitrites-nitrates
Name two substances in the body that contain nitrogen
Amino acids
Nucleic acids eg dna and rna
For fish farming, in terms of nutrition, what would you say to maximize yield;
Feed in high protein food
And feed regularly but in small amounts to prevent the accumulation of food
What happens if red blood cells are placed in a solution with large amount of water
The cells burst through lysis,
Therefore no red blood cells will be present
It will form a clear red liquid as the haemoglobin dissolves
Four differences between asexual and sexual reproduction
-asexual involves only one parent CELL
-no gametes are formed, (so there is no meosis)
-no fertilization occurs, so no fusing of gametes
-offspring are genetically identical, so no genetic variation
How can you remove starch from a plant and how does this work
By placing in a dark room
FOR 24 HOURS
bc leaf can’t photosynthesize so isn’t making glucose,
Therefore it uses its starch reserve to make glucose instead
What is a safety precaution that you should take when removing chlorhydrique form a leaf
When heating ethanol, use a water bath, instead of a Bunsen burner
How is water transported into the plant for photosynthesis
Absorbed in the roots from the soil and is transported through the xylem into the leaf
How plant is adapted for photosynthesis(6)
1)flat, large sa,v for diffusion of gases, and absorption of light
2)thin, for short diffusion distance
3)upper epidermis is transperçant to allow light to enter in
4)lower surface has many stomata for co2 to enter
5)palisade mesophyl layer has many palisade cells which contain a lot of chloroplasts with chlorophyll in them to absorb sunlight
5)contains a vascular bundle with xylem in them to absorb water
Difference in function of atria, and function of ventricles
Function of atria is to receive oxygenated blood from the pulmonary vein
And receive deoxygenated blood form the vena cava
And it contracts to push blood through the ventricles.
Ventricles contract to push blood out of the heart.
Where oxygenated blood leaves through the aorta to go to rest of the body.
And deoxygenated blood leaves the pulmonary artery to go to the lungs
What is a balanced diet
Diet that consists of all the food groups,
In their required proportion
what is the filtrate
smaller molecules that are filtered out of the bowman’s capsule during ultrafiltration
state the name of two processes that occur in the nephron
ultrafiltration
selective réabsorption
blood comes from which blood vessels in the nephron
the renal artery, which comes from the aorta
what is the formula for finding the amount of energy in a good sample
E= Mass of water4.2temp change of water/mass of food sample
what are two ways in which mutations occur that are not harmful
in the process of meosis, where different combinations of alleles are made which lead to different phenotypes
or hapoens spontaneously in cells during mitosis when dna is duplicated
what is evolution.
what is natural selection.
-gradual change in the inherited characteristics of a population over time through natural selection.
-the process whereby those better adapted to their environment suffice and reproduce, passing on their advantageous alleles to their offspring
what is female part of a plant called.
what is male part of a plant called. what is green but at bottom of flower called.
carpel
stamen
sepal
explain the structure of a seed
-a seed is formed from an ovule
-the ovule wall forms the seed coat which is also known as the testa
-inside it is filled with the cotyledon which is the food store
-it consists of a plumule which will become the shoot and a
-radicle, which will become the root
apart from flagellum and enzymes in the head piece, what is another adaptation of a sperm cell
contains many mitochondria in its midpiece. so that can produce energy for respiration for flagellum to move
give two adaptations of an egg cell
.contains cytoplasm with a store of energy to provide the zygote with energy for mitosis.
.contains a jelly like coating that will change shape after fertilization so that no new sperm can enter
four functions of the placenta
-provides oxygen,amino acids and glucose to growing fetus
-protects from pathogens
-removes waste products such as carbine dioxide
-provides hormones to prevent menstruation
a formula that u can use for sampling
mean per quadrat * total area of field
(number of organism counted/total quadrants used)
What is the name of the blood vessel that goes from the liver to the gut
The mesentric artery
The hepatic portal vein goes form where to where
The gut to the liver
What are the adaptations of the ventricles and of the atria
Left ventricle is thicker than tight so that it can withstand higher pressures.
Atria are thin so that they can stretch when blood enters and contract to push blood through tricuspid and bicuspid valves
How does the nervous system increase heart rate after exercise
Receptors in the Aorta and carotid artery detect increased carbon dioxide levels as a result of excercise, so they send electrical impulses to the medulla, which causes heart rate to increase
How does fear increase heart rate
Adrenal glands release the hormone adrenaline which binds to receptors in the heart, causes heart rate to increase, therefore blood pressure increases. More oxygen is supplied to the muscle cells so they have more energy. This is called the fight or flight
Explain the effect of nicotine on coronary heart disease
Causes blood cells to become more sticky and so narrows blood vessels.
This makes them more likely to become clogged with cholesterol.
So less oxygen can be transported, so more strain on the heart, so increased bp and heart rate.
It also means that to compensate heart muscle cells begin respiring anaerobically, which produces acidic lactic acid cna denature enzymes and kill heat muscle cells.
Explain the effect of carbon monoxide on coronary heart disease
Binds to haemoglobin so red blood cells can carry less oxygen around the body. This means to compensate, there is a higher heart rate and higher blood pressure.
This can damage walls of coronary artery and so makes look clots more likely. Reduced oxygen to heart muscle cells so heart attack.
In the stomach, what makes enzymes acidic optimum temp.
What is the order of the small intesine
Hydrochloric acid.
Duodenum
Ileum
What is the role of the lacteal
Present in the villi, to transport fatty acids away
Test for glucose
Crush and add to distilled water and shake.
Add Benedict’s solution.
Heat in a water bath
Should turn back red
Function of calcium, vitamin d and iron in the diet
Calcium, helps make teeth and bones
Vitamin d, helps calcium absorption to make teeth and bones stronger
Iron, part of haemoglobin in the blood so helps to transport oxygen
Functions of;
Conjunctiva
Virtuous humour
Aqeous humour
Sclera
Retina
Optic nerve
Blind spot
Conjunctiva-lubricates eye to prevent eyelashes from sticking
Virtuous-keeps eye wet, keeps retina against wall
Sclera-muscular later maintains the shape of the eye
Retina-contains light receipts cells
Optic never-contains a bundle of sensory neurones that sends electrical impulses to the brain
Blind spot-point at which the optic nerve leaves the eye and there are no receptor cells
Apart from blood pressure and heart rate increasing, what four other things happen adrenaline is released in the body
-body hairs stand up
-pupils dilate
-glycogen in liver converted into glucose
-blood diverted from small intestine to muscles
What is type 1 diabetes, and type 2 diabtes
Type 1 is when body doesn’t make enough insulin. It is inherited.
Type 2 is when body becomes insulin resistant. Caused by obesity
What is the role of the myelin sheath, and of the dendrites.
What is difference between nerve and neurone
Myelin sheath insulates electrical impulses so that they work at a faster rate.
Dendrites connect neurones to other neurones
Nerve is a bundle of neurones
After an electrical impulse has been transmitted to the sensory neurone, what happens next
Sensory neurone transmits electrical impulse to a relay neurone, which is in the spinal chord, in the cns region of the brain.
The relay neurone then synapses with a motor neurone. This then sends electrical impulses across to an effector.
Reflex actions are coordinated by which part of the cns
The spinal chord
Explain the process of vasoconstriction
Arterioles constrict and more narrow
So less blood can flow to capillaires near surface of skin
Therefore less heat is lost to environment
Label diagram of the skin
In bio favourites
What substance cna u use to remove co2 from a plant.
And what substance can u use to measure co2 level in a plant.
Soda lime (in a bell jar)
Hydrogen carbonate indicator
What is a limiting factor
Part of the reaction in shortest supply so that it limits the rate of reaction from increasing any further
What is transpiration
The evaporation of water vapour through the spongy mesophyl, followed by the diffusion of water out of the stomata
How does increasing light intensity affect transpiration
Increases the rate
Because in high light intensity, guard cells take in water and become turgid,
So the stomata is opened
Therefore more water can evaporate and diffuse out
Function of semi lunar valves
Prevent the backflow of blood into the ventricles
Community definition:
Species:
Population:
Community- all populations living in an area at same place at same time
Species- group of organisms who are able to interbreed and produce fertile offspring
Population: group of same species in same area same time
Role of vitamin d
Role of calcium
Vitamin d- helps with absorption of calcium, to make strong teeth and bones
Calcium- strong teeth and bones
During vasoconstriction which blood vessels constrict
Arterioles
so less blood is therefore transported to the capillaries
(Remember it is not the capillaries themselves that constrict)
Two effects of acid rain on ecology
-damage leaves
-release toxic substances from soil to prevent mineral absorption
Explain how soil erosion works because of deforestation
Soil erosion,
Roots can no longer hold together soil
So minerals can be easy leached infertilensoil
4 differences between active transport and diffusion
diffusion passive (1)
• diffusion from high concentration to low /
requires concentration gradient (1)
• active transport requires ATP / energy/ oxygen / respiration (1)
• active transport requires membrane / carrier proteins (1)
• diffusion can take place in non-living systems
Apart from surface area to volume ratio, and short distance, temperature, name three other factors that can affect movement inside and out of cells
-amount of oxygen, because more oxygen means more atp so faster
-size of particles, smaller size means faster rate of diffusion
-concentration gradient, steeper concentration gradient means faster rate
Explain the process of meosis
1)chromomes number is replicated so that each chromosome forms an x shape chromosomes with two sister chromatids
2)chromosomes align at the centre and attach to spindle fibres
3)during the first division, one chromosome from each pair of homologous chromosomes is pulled apart to the opposite side of the cell
4)during the second division, one arm from each chromosome is pulled apart to from two daughter cells with 23 chromomes each
5)this results in genetic variation due to the random shuffling ofc hormones, meaning each time a gamete is made, it has a different combination of maternal and paternal chromosomes
Why may a mutation not affect the phenotype
-may occur in non coding dna, which doesn’t code for a specific protein
-may occur in a recessive allele, and so is not expressed in the phenotype
-may only alter it slightly so that the function of the protein is not changed
Function of the nucleus
Contains the genetic material of the cell in chromos so controls the growth and activity
2 functions of the nucleus
Contains the genetic material in the form of chromomes so controls teh growth of the cell
Controls cell division
What are lipids made from
One glycerol molecule attached to three fatty acids
Three uses of stem cells in medicine
-can be used to treat many diseases like diabetes
-can repair and replace damaged tissue
-can be used to make persons organs so prevents organ rejection
Cell wall fucntion
Provides strength and support to cell
Cell membrane function
Holds the cell togther
Controls what enters and leaves the cell
Vacuole function
Contains cell sap and acts as a storage
And provides support to cell
Three limiting factors of photosynthesis
Carbon dioxide
Light intensity
Temperature
Give four plant deficiencies according to each type of mineral
Nitrates—) yellow and poor plant growth
Magnesium—) yellow
Potassium —) yellow and dead spots
Phosphates—) purple
Function of iron in the body
Part of the haemoglobin in red blood cells so helps to transport oxygen around. (Remeber it doesn’t produce haemoglobin but helps it)
Who needs more energy audits or children
Adults.
But children require more protein in their diet for growth
Four adaptations of the ileum
1)long and folded for large sa.v
2)contain many villi for large sa.v
3)contain good blood supply, for conc gradient for diffusion between ileum and blood supply
4)thin for short diffusion
Equations for anaerobic
And aerobic respiration in animals
Anaerobic:
Glucose —) lactic acid (+atp)
Aerobic
Glucose + oxygen —) carbon dioxide dioxide + water (+ATP)
What is oxygen debt
The amount of oxygen that is needed to oxidize and breakdown the lactic acid accumulated from anaerobic respiration
Effect of nicotine on the body
Causes vasoconstriction because makes cells stick together.
So more cholesterol can build up so more clots. So either, to compensate body respires anaerobically and so this produces lactic acid, acidic ph, enzyme denature. Or causes heart rate and blood pressure to increase so more strain on heart. Can also cause damage to walls and cause clotting
What substance causes emphysema
Carcinogens
State the products of excretion from
The lungs
The kidney
The skin
Lungs: carbon dioxide, water
Kidney: urea, excess water, excess mineral ions
Sweat: water, mineral ions, (aka sweat)
State the products of excretion from
The lungs
The kidney
The skin
Lungs: carbon dioxide, water
Kidney: urea, excess water, excess mineral ions
Sweat: water, mineral ions, (aka sweat)
3 conditions that need to be controlled within the body:
Water
Temperature
Blood glucose
Role of the conjunctiva
Lubricates the eye,
Prevents eyelids from sticking together
What is biomass
The dry mass of all the living organisms in an area
Why is starch used as an energy store instead of glucose
Because it is insoluble
And so will not dissolve inside the plant so will not effect the way in which water moves in and out through osmosis, so can be stored in large amounts
Three functions of Oestrogen in menstrual cycle
-inhibits FSH
-stimulates LH
-repairs lining of uterus
Three adaptations of root hair cell for water absorption
-elongated fo large surface area
-thin for short diffusion distance
-low water potential, so concentrated with cell sap
Why does cloning often need to be done many times
Not all eggs survive
Not all embryos survive
Where does ultrafiltration occur
Glomerulus
(According go past papers)
Two functions of paddle stirrers
Keep microorganisms in contact with nutrients
And distribute heat
