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What is a whip like tail called on a bacteria
A flagellum
How does a flagellum help bacteria
It helps them move
Function of the nucleus
Contains genetic material controlled the activities of the cell
Function of the cytoplasm
Most chemical processes take place here, controlled by enzymes
Function I the cell membrane
Controls movement of substances in and out of the cell
Function of the mitochondria
Most energy is released through respiration here
Function of ribosomes
Protein synthesis happens here
What part of cells produce protein
Ribosomes
What is the function of cell walls
Strengthens plant cells
What is the function of chloroplasts
Contains chlorophyll which absorbs light energy for photosynthesis
What is the function of the permanent vacuole
Filled with cell sap to help keep the cell turgid
What does turgid mean in a biology context
Enlarged and awoken with water
Which two inventors are credited for creating the first microscope
Hand and saccharides Janssen
What was the problem with early microscopes
They did not magnify to a great extent
How many times can modern light microscopes magnify
1500 times
How many times can an electron microscope magnify
Two million times
How has the improvement of microscopes led to scientific discoveries
Has allowed scientists to see small things such as cells in much greater detail
As a result our understanding of their function has improved
How can we calculate the length of a magnified object
Length of object=length of magnified object/magnification
What are enzymes
Large molecules that speed up the chemical reactions inside cells, each type of enzyme does one specific job
What are enzymes
Long chains of protein
What are proteins made of
Long chains of amino acids
What is aerobic respiration
Where does it take place.
Aerobic desperation is our main source of energy
It takes place in the mitochondria
What are mitochondria
What’s in them
Where are they in the body
Oval structures with a folded inner membrane
They have a large number of different enzymes inside them. Responsible for different stages of respiration
They are found in large numbers in places like the liver and muscles-places that need a lot of energy
What are enzymes
Soluble protein molecules that speed up chemical reactions
What are the compact structures which contain DNA
Chromosomes
What is the shape of DNA
The double helix
How are the two strands of a DNA double helix held together
Hydrogen bonds between pairs of bases
How does a cell make a duplicate copy of each DNA molecule
The bonds between the two strands of DNA break. The strands unwind new bases then join each old strand to make two new double helix eps
What are the three steps of the duplication of the old DNA helix
DNA spiral unzips
Free nucleotides lock onto bases
Two copies of the original spiral are formed
How do the order of the bases in DNA control protein
Each amino acid has its own code of three bases, each time the same three bases are in the genetic code the same amino acid is added to the chain to make a protein
What is the experiment for extracting DNA from cells
Peas
Salt water and detergent are added to mashed up peas
This mixture is left at sixty degrees for fifteen minutes
Then filter the mixture
Pour iced ethanol on the filtrate, the DNA will float to the surface
What are the steps in order to the discovery of the DNA molecule
Rosalind franklin and Maurice Wilkins studied and photod X-rays of DNA
James Watson and Francis crick worked out the three d structure of the molecule
Everyone except for franklin won Nobel prizes because she died
What was the human genome project
A project to find the order of all the three billion base pairs in humans
To develop faster methods for sequencing DNA
When was the human genome sequencing finished
Two thousand and one
Why did the human genome project use several people
To get an average sequence
Scientists from how many countries collaborated to work on the Hgp
18
How is the human genome project useful
Improved genetic testing
Location of genes which are linked to encreased chance of inheriting a disease
New gene therapy treatments
New knowledge of how humans have evolved
Personalised medicines
Who invented genetic fingerprinting
Sir alleviated Jeffrey’s
How does genetic fingerprinting work
It uses small genetic differences to make a picture like a bar code
What are the two differences between cloning and genetic engineering
Cloning
Produces exact copy’s
Genes are copied within the same species
Genetic engineering
Ptoduces a unique set of genes
Genes can be swapped across species
How gm works
Enzymes cut DNA containing a certain gene from one organism
And join them into a gap in the DNA of another organism
What is an example of genetic modification
Bacteria modified to produce insulin
How are bacteria modified to produce insulin
Steps.
Restriction enzyme cuts out the gene that produces insulin
Enzyme cuts bacteria plasmid an inserts human insulin gene into the gap
Bacteria produces insulin
Three examples of genetically modified plants and animals to vena fit humans
Gm insulin
Golden rice produces extra beta carotene used to make vitamin a
Herbicide resistant crops
Positives of gm insulin
Is easier to create high quantities
Less likely to cause an adverse reaction
Overcomes ethical concerns from vegetarians
Negatives of golden rice
Fears it will cross breed with wild rice
Worries that gm organisms might harm people
Beta carotene levels aren’t high enough to make a difference
Are expensive
Possible disadvantages to herbicide resistant crops
Potential development of herbicide resistant weeds
Loss of biodiversity as fever weeds survive to provide shelter for animals
Who invented the periodic table
Dmitri Mendeleev
What are the two types of DNA in bacteria called
Plasmid and chromosomal
What’s the benefit of humans being multi cellular
Three
Cells can be specialised to do certain things
Groups of cells can function as organs making a more efficient but complex organism
The organism can grow very large
What does it mean if a cell is diploid
It has two of each chromosome
What is mitosis
The type of cell division used for growth repair and asexual reproduction
What does mitosis produce
Two cells that are identical to each other and it’s parent cell
What are the four steps of mitosis
Chromosomes in nucleus are copied.
Chromatids pulled apart and moved towards poles
Chromosomes separate
Cell divides into two genetically identical daughter cells
Why is cell division in multi cellular organisms necessary
The larger the cell becomes the smaller it’s surface area to volume ratio becomes. Objects with a small range find it difficult to maintain exchange of materials with their environment. Large cells could run out of oxygen and accumulate too much waste like co2
What is all reproduction in humans
Sexual
What is a haploid cell
When a cell has half the usual amount of genetic material
What are the cells that combine to form the zygote called
Gametes
How many chromosomes do human zygotes contain
46
How many chromosomes do human gametes contain
23
What is the type of cell division that produces gametes called
Meiosis
What is responsible for causing genetic variation
Meiosis
What is a gamete
A cell with half the normal amount of chromosomes only used for reproduction
What is a zygote
Cell formed when two gametes combine
What is fertilisation in reproduction
Term to describe the joining of two gametes
What is a haploid
Having half the normal amount of chromosomes
Diploid
Having the normal amount of chromosomes
What are adaptions to the sperm gamete to help it perform it’s job
They have a tail to propel them
Many mitochondria for energy
The front of the sperm contains enzymes to digest the egg membrane
What are adaptions to the egg gamete to help it perform it’s job
Has a large food store to support the developing zygote until it can feed from the placenta
7 steps of meiosis
Parent cell
Chromosomes make identical copy’s of themselves
Similar chromosomes pair up
Sections of DNA get swapped
Pairs of chromosomes divide
Chromosomes divide
Four genetically different haploid daughter cells produced
Which process of cell division is used in asexual reproduction
Mitosis
Which plants can do asexual reproduction
A potato plant can many tubers which each of which can grow into a new plant
Strawberry and spider plants produce long stems with tiny plants on the end these runners can produce several new plants from one parent
What are the steps of cloning
Removal of a diploid nucleus from a body cell
Emu elation of an egg cell (take out the nucleus)
Insertion of diploid nucleus into the emu cleated egg cell
Electrical stimulation of the diploid nucleus to divide by meiosis
What is an example of cloning
Dolly the sheep
Ethical issues surrounding cloning
Two
Restriction of cloning humans also restricts scientific research
Cloning plants is done all the time and causes the public less ethical and moral concerns
How are cows cloned using embryo transplants
5 steps
Sperm is taken from a bull in a high yield dairy herd
Cow is artificially inseminated with sperm
Zygotes develop into embryos in cow and then removed from uterus
Embryos are split into several smaller embryos each of which can grow into a new calf
Embryos are placed into the uteruses of foster mums
How would we go about genetically modifying pigs to grow human organs
The pigs would have human genes inserted into their cells so the organs would not be rejected when transplanted into human bodies
Once the insertion of human genes had been done we would clone the pig as this is less hard than inserting human genes
Two disadvantages to cloning
If a clone is susceptible to disease or changes in environment then all the clones will be susceptible
It will lead to less variation and less opportunity to create new varieties in the future
Two advantages to cloning
All the new organisms are identical- they will all have the desired characteristics
Organisms that are difficult or slow to breed can be reproduced very quickly. Some plants do not produce seeds others lie dormer for a long time
4 things stem cells can be used for
Making new brain cells to treat people with Parkinson’s
Rebuilding bones and cartilage
Repairing damaged immune systems
Making replacement heart valves
What is therapeutic cloning
Cloning one of your cells to produce an embryo then taking stem cells from this for your use
What are the six steps to therapeutic cloning
Nucleus taken out of human egg cell
Nucleus from patients cell put into the egg cell
Egg cell stimulated to develope into an embryo
Stem cells taken from the embryo
Stem cells grown in a container of warm nutrients
Stem cells treated to grow into required cell types
To enable genes to code for proteins the bases Atgc get to get her in triplets
Each protein is made up of large numbers of amino acid molecules
Each triplet of bases codes for an amino acid
Amino acids are made in the order and number dictated by the base triplets
Amino acids join together a long chain to make a protein molecule the number and sequence of amino acids determines which protein results
What is transcription
The first part of the process of making protein
It takes place inside the cell nucleus
Transcription involves copying the DNA
What are the steps of transcription
The DNA unzips so that both genes are separate one strand is used as a template
Complimentary bases attach to the strand being coded
Thymine base t is not present and a different bace u joins with a in the way that t would have done
This forms a strand of messenger RNA
What replaces t in transcription
U
What do ribosome’s do
Make protein to be used inside the cell
What takes place in translation
This is when the messenger RNA is ‘interpreted’
What are the stages of translation
6
The mRNA attaches to a ribosome
The ribosome reads the mRNA
The ribosome decodes the mRNA in groups of three
Base triplets or codons which are complimentary to bases in transfer RNA
The tRNA is specific to an amino acid that collects and returns to the mRNA
Bonds form between the amino acids and polypeptide Is formed
The polypeptide chain folds up and becomes a specific shape forming a protein
What is the part of the enzyme molecule that matches the substrate called
The active site
What is the chemical that an enzyme reacts with called
The substrate
How fast are enzymes reactions at cold temperatures
Slow
Do enzymes reactions speed up as they heat up
Up to a point
After the optimum temp has been passed it slows down the reaction speed
What ph do most enzymes work best at
Neutral conditions
What is the relationship between substrate concentration and enzyme reaction speed
The higher the concentration of substrate the faster the reaction-up to a point
What is it called when enzymes break down due to heat
Denaturing
What is the name for the fact enzymes can only do one job due to their shape
The lock and key mechanism
Where does aerobic respiration occur
Mitochondria
What is the word equation for aerobic respiration
Gucose+oxygen=>carbon dioxide+water
What is the energy made in respiration used for
Used to make large molecules from small ones
To allow muscles to contract
To maintain a constant body temp
Which way do arteries carrie blood
Away from the heart
Which way do veins carry blood
To the heart
What are the tiny blood vessels that are close to the body’s cells called
Capillaries
In what blood vessel does diffusion occur
Capillaries
How does the rate of carbon dioxide diffusion have to change during exercise
Oxygen and glucose must be delivered to cells more quickly
Waste co2 must be removed more quickly
When does anaerobic respiration occur
When the body can’t get oxygen to the blood quickly enough
What is the word equation for anaerobic respiration
Glucose=>lactic acid
What are the negatives of anaerobic respiration
Energy output is much lower
Lactic acid that forms in muscles cause pain
What is the oxygen dept built up after exercise called
Excess post exercise oxygen dept
EPOC
Why is an oxygen dept built up after exercise
It is because glucose is not broken down properly to form carbon dioxide and water some of it is broken down as lactic acid
Panting after exercise provides oxygen to break down the lactic acid
Why does an increased heart rate help break down lactic acid
It allows lactic acid to be carried away from the blood to the liver where it is broken down
Why is blood being carried away from the heart in arteries under pressure
Because of the heart contracting
What is the name for the high pressure measurement when the heart contracts
Systolic pressure
What is the name for the lower measurement of pressure between heart beats
Diastolic pressure
What is plops pressure measured in
Millimetres of mercury
mmHg
A young healthy person may have a blood pressure of 120 over 70 what does this say about their two types of blood pressure
Their diastolic pressure is 70 mmHg
Their systolic pressure is 120mmHg
What are the lifestyle factors blood pressure varies by
Five
Diet Stress Exercise Body mass Alcohol consumption
What is the process in which water evaporates in the leaves resulting in more water being drawn up from the roots
Transpiration
What is the function of leaves
Photosynthesis
What is the stem like tissue that runs through the centre of leaves called
The midrib mid…..rib
Remember that
What is the thin green tissue on leaves called
The blade
What are the small stems that come out of the midrib on leaves called
The veins
What is an adaption to help leaves absorb more light
Large surface area
What is an adaption to make the distance for carbon dioxide to diffuse into cells short
Leaves are thin
What is an adaption that makes leaves able to absorb sunlight to transfer energy into chemicals
Chlorophyll
What is the adaption of leaves to be able to transport water and carbohydrates and to add support
Network of veins
What is the part that allows leaves to diffuse carbon dioxide into it
The stomata
What is another name for stomata
Epidermis
Where are the stomata on leaves
Underneath
No waxy layer to block gas flow
What are the two cells that surround the stomata called
The guard cells
What is the palisade layer of cells used for
Photosynthesis
What is the adaption to help more light to reach the palisade cells
The epidermis is thin and transparent
What is the adaption to protect the leaves but not block out light
Thin cuticle made of wax
Leggy is the palisade layer near the surface
To absorb more light
What is the reason for the sponges layer in leaves
It spaces allow carbon dioxide to diffuse through the leaf through the stomata and to encores aw surface area
Why do palisade cells contain many chloroplast
To absorb all the available light
What are the three things that can limit the speed of photosynthesis
Light intensity
Carbon dioxide concentration
Temperature
How do farmers increase the rate of photosynthesis
Burn paraffin lamps to increase co2 levels
Use artificial light so crops can grow beyond daylight
How does water get taken out of leaves in transpiration
Diffusion
Which type of tube is used in transpiration
Xylem
What makes a constant flow of minerals from roots to leaves
Xylem cells make a continuous tube
How is transpiration naturally slowed down in plants when they are low on water
Wilting
How are plants transpiration rates slowed unnaturally
Removing leaves through cuttings before they have a chance to grow new roots
How does light affect transpiration
Increases with light as the stomata open wider to increase carbon dioxide for photosynthesis
How does temp affect transpiration
It increases the rate as evaporation and diffusion are faster in warm conditions
How does wind affect transpiration rate
Faster in wind, water vapour is removed more quickly by wind speeding up diffusion
How does humidity affect transpiration
Slower when humid
The leaf is already surrounded by moist air, diffusion is the movement of a high concentration to a low concentration
What does the xylem do
Moves water and solutes
What does the phloem do
Moves good substances from leaves to the rest of the plant
Why are the phloem and xylem near the edge of the stem
To resist compression and bending forces
Why are the phloem and xylem in the centre of the root
To resist bending and stretching forces
What is the difference in the movement of food or water from flown to xylem
Phloem uses translocation xylem uses transpiration
What is the difference between the phloem and xylems tubes
Xylem columns of dead hollow reinforced cells
Phloem columns of living cells
In what process do plants absorb water from the soil
Part of transpiration
Osmosis
What part of the plant does osmosis
Root hair cells
How are root hair cells adapted to osmosis
They have a large surface area to speed up osmosis
What is the word for the movement of the water through the roots to the rest of the plant after osmosis
Transportation
Why is water used for in plants
Four points
Reactant in photo synthesis
Supports leaves and shoots by keeping cells rigid
It cools the leaves by evaporation
Transports dissolved minerals around the plant
How are leaves adapted to photosynthesis
Two
Large surface area
Have stomata holes for carbon dioxide
How do leaves prevent too much water loss
Two
A wax cuticle to stop water escaping through the epidermis
Less stomata on their top surface to reduce water loss
How are plants in dry conditions stomata adapted
They are very small and only at the bottom of the leaf to reduce water loss
What happens to guard cells in low light
They loss their water to become flaccid causing the stomata to close
Preserves water
Why do plants wilt when in contact with sea water
Osmosis causes loss of water due to the high solution
What is the fact plant cells are hard called
Turgid
What does turgidity of plants do
Supports their weight
Why do plants wilt
If the plant loses water faster than it can be absorbed it loses turgid pressure and becomes flaccid
Define osmosis
A movement of a substance from a high concentration area to a low concentration area through a partially permissible membrane
What is biodiversity
The variety in different species living in an area
What are the first two thing a scientist will want to know about a species present
Where it is found
Distribution
The number of that organism present
Population
How do scientists overcome the fact they can not sample an entire environment in detail
They sample a small section or portion
Sampling several small sectors is representative to the whole area
What is a pooter
A small insect catcher. The breather sucks on the end of a tube and it sucks the insect up
What is a sweep net
A net used in areas of long grass to catch organisms
Can also be used in ponds
What is a pitfall trap
Used to catch small crawling insects
Pretty much a cup in a hole with some wood over it
What is a quadrate
Square frames of a known size use to sample all the plant species in one area
What is a light intensity meter
A device that measures light intensity
What is a ph probe
A ph measurer
Sometimes also tests temp
What is the order of development from the beginning of life to now
Animals now are more developed because we have had more time for evolution
Proven by fossils old to new
What are the three things that slow the decaying process helping to preserve tissues
Insufficient oxygen eg organism trapped in Amber
Low temp eg organism frozen in a glacier
High soil acidity eg when an animal falls into a peat bog
What are some difficulties in tracing the story of evolution
Three
Big gaps in fossil records
Soft tissues decay scientists have to guess what animals looked like
Lots of fossils not yet found
What is the pentadactyl limb
Five fingered
Most vertebrates have pentadactyl limbs what does this suggest
We all descended from a common ancestor
What is a case study for an animal that has lost its pentadactyl limbs
A horse
What are the three vena fits of being multicellular
Cells can be specialised to do specific tasks
Groups of cells can function as organs making a more efficient but complex organism
The organism can grow very large
Where does growth mainly occur in plants
Shoots
Specialised growth zones like buds
Root tips
Where does growth occur in animals
New cells can be made by most tissues
How does growth occur in plants
Size increase often caused by absorbing water into the vacuole
How does growth occur in animals
Increase in the number of cells
Can plant cells differentiate into any cell
Yes most can
Can animal cells differentiate into any cell
No only stem cells can do this
What are stem cells
Undifferentiated cells that can turn into different tissues
How is human growth measured
Using percentile graphs
What does blood consist of
Plasma
Red blood cells
White blood cells
Platelets
What does blood plasma do
Transports dissolved substances around the body
What sort of substances does blood plasma carry around the body
Hormones
Nutrients-water. Glucose. Amino acids.
Minerals and vitamins.
Waste substances such as carbon dioxide and urea.
What do red blood cells contain to help them carry oxygen
Haemoglobin
What do platelets do
Cause clotting to stop bleeding when blood vessels are cut
What is the definition of tissues
A group of cells with a similar structure and function which work together to perform a particular job
Five examples of tissues
Muscle Lining of the intestine Lining of the lungs Phloem Root hair tissue
Give def of an organ
A group of different tissues which work together to perform a particular job
Give six examples of organs
Heart Lung Stomach Brain Leaf Root
HIV def of an organ system
A group of fife rant organs which all work together to do a particular job
Give six examples of organ systems
Circulatory system Respiratory system Digestive system Nervous system Reproductive system Leaf canopy
What is the name for the fact that the blood on the left side of the heart and the right side of the heart is kept separate
Double circulation
What is the aorta
The body’s largest artery
Takes oxigen aged blood from the left ventricle to the body
What is the pulmonary artery
Carries blood from the right vent rival to the lungs
Right atrium
Receives detoxing instead blood from the body
Pulmonary vein
Takes oxygenated blood from lungs to left atrium
Left ventricle
Pumps oxigen acted blood into the aorta
Right ventricle
Pumps deoxygenated blood into the pulmonary artery
Coronary vessels
Supply the heart muscle with its blood supply
Arteries
Carry blood away from the heart
Veins
Carry blood to the heart
Bicuspid valve
Valve between left atrium and lady ventricle
Tricuspid valve
Valve between the right atrium and the right ventricle
Vena cava
The largest vein in the body
It carries blood from body back to heart
Which seven blood vessels and tubes etc etc does deoxygenated blood flow through
Vena cava Right atrium Tricuspid Right ventricle Semilunar Pulmonary artery Lungs
Which seven parts of the body does oxygenated blood flow through
Pulmonary vein Left atrium Bicuspid Left vent rival Semilunar Aorta Body
Why does the left ventricle have a thicker wall than the right
It has a higher pressure because it pumps
What is the problem with narrow rigid arteries
Need more pressure to pump blood through them
Increased blood pressure leads to heart problems over time
Cholesterol leads to this a change in diet can solve the problem
What are the problems with leaking heart valves
Make blood circulation inefficient
Can be replaced in open heart surgery with donor valves or mechanical valves
What problems occur due to a faulty pacemaker
Irregular beating of the heart causes inefficiency
What are the problems associated with mechanical or electrical heart components
Rejection by the immune system
Finding a way to reduce the size of the components to fit
Providing a power supply
What are the problems with transplants
Difficult to find suitable donors with healthy hearts that match the tissue types of patients
People need to take drugs to prevent their immune system rejecting
Encreas end chance of rejection
What are the circulatory systems parts and their use
The heart is the pump that keeps blood flow going
Arteries carrie blood away from the heart
Veins carry blood to the heart
Capillaries are close to cells they exchange materials with them
How is food moved through the digestive system
Peristalsis squeezing of longitudinal muscles to move food
Which enzyme catalyses starch to augers
Amylase
Which enzyme catalyses proteins to amino acids
Protease
Which enzyme catalyses lipids to fatty acids and glycerol
Lipase
Where is amylase produced
The salivary glands
Where is protease produced
Stomach pan crease and small intestine
Where is lipase produced
Pancreas and small intestine
What are lipids broken into by lipase
Fatty acids and glycerol
What does bile do
Neutralises the food after it has been in the stomach as this helps enzymes work
It also emulsified fats to provide a larger surface area for the lipase to work
Where is bile produced
Where is bile stored
Produced in liver
Stored by gall bladder
Where are digested food molecules absorbed
The small intestine
How is the small intestine adapted to help absorb food
Has a large surface area due to hair like vili
The wall of the small intestine is thin
The wall also contains many capillaries to transport food
What do villi do
encrease the small intestines surface area and absorb food
What is the process in which food goes into the blood stream through villi called
Diffusion
What do manufacturers claim probiotics do
Improve the digestive system
Help defend disease
Reducing allergies
What are prebiotics
Food for probiotic bacteria
In what conditions do the enzymes in the small intestine work best
Alkaline
