biology paper 1 Flashcards
1
Q
What are all living things made off?
A
cells
2
Q
What 2 things can an organism be?
A
Eukaryotes and Prokaryotes
3
Q
What cells are Eukaryotic?
A
Animal and plant cells (more complex)
4
Q
What cells are Prokaryotic?
A
Bacteria cells (simpler and single celled)
5
Q
What is in the nucleus?
A
contains genetic material, that controls the cell’s activities. (DNA)
6
Q
Job of cytoplasm?
A
a gel like substance where chemical reactions occur, (contains enzymes)
7
Q
Job of cell membrane?
A
holds the cell together and controls what goes in and out.
8
Q
Job of mitochondria?
A
respiration occurs here so transfer of energy can occur.
9
Q
Job of ribosomes?
A
to help translation of genetic material in protein synthesis.
10
Q
Job of cell wall?
A
support and strengthen cell (made of cellulose)
11
Q
Job of a large vacuole?
A
contains cell sap and helps maintain the internal pressure.
12
Q
Job of chloroplast?
A
photosynthesis occurs here so food can be made for the plant, it also contains chlorophyll
13
Q
What do animal and plant cells have that bacteria cells do not?
A
A nucleus
14
Q
Job of flagellum?
A
help rotate and move bacterium so that it can be moved away from harmful toxins or towards nutrients or oxygen
15
Q
What is the function of the egg cell? and what it contains
A
Carry female DNA and to nourish the embryo in early stages. nutrients in the cytoplasm so the embryo can be fed, haploid nucleus and after fertilisation the membrane changes structure to stop more sperm getting in so offsprings end up with the right amount of DBA
16
Q
What is the function of the sperm and what is in it?
A
Its function is to transport the male’s DNA to the females egg, it has a long tail to swim, lots of mitochondria in the centre to provide energy so it can swim far enough, an acrosome at the head so it can digest though the egg membrane and has a haploid nucleus.
17
Q
What are ciliated Epithelial cells specialised for?
A
Moving materials
18
Q
What two microscopes are used for studying?
A
Light and electron microscopes.
19
Q
What microscopes is better and why a Light or Electron microscope?
A
An electron microscope while much more expensive is better as it has a higher resolution and magnification allowing you to see smaller things with more detail and structure.
20
Q
How do you convert from millimetre downwards to a picometre and from a picometre upto a millimeter?
A
multiply by 1000 3 times to get to a picometre and picometre to millimetre dived by 1000 3 times
21
Q
What are enzymes and what produce them?
A
Enzymes are catalysts made by living things
22
Q
Why do enzymes have special shapes?
A
So they can catalyse certain reactions
23
Q
What happens to the enzyme and substrate after a reaction?
A
The enzyme remains unchanged however the substrate splits in half and changes into two products off the reaction.
24
Q
What happens if you change the temperature in an experiment?
A
the rate of an enzyme catalysed reaction changes
25
What happens to an enzyme if the reaction gets too hot?
the enzymes active site changes this means that the substrate can no longer fit causing the enzyme to become denatured.
26
What do all enzymes have?
An optimum temperature
27
What is an optimum temperature?
the temperature that the enzymes work best at
28
What can affect a reaction?
the temperature, ph and substrate concentration.
29
What is the normal optimum Ph?
pH7
30
What is the optimum Ph for pepsin?
pH2
31
What happens if you have a higher substrate concentration? Why?
You get a faster rate of reaction as it is more likely that the enzyme and substrate molecule will meet up.
32
What happens if you go above or below the optimum pH?
The reaction takes longer to work or won't work at all.
33
What happens once you go above the optimum substrate concentration?
Once it goes above the optimum concentration the reaction levels out and will not go any faster as all sites are filled.
34
How do you test for Starch?
With iodine.
If starch is present colour changes from browny orange to a dark blue black colour.
35
What test do you use for Lipids?
The emulsion test
you shake substance with ethanol for 2 minutes
any lipids present will precipitate into a milky emulsion.
more lipids=more milky emulsion
36
How do you test for proteins?
Use the Biuret test,
add a few drops of potassium hydroxide to make an alkaline solution
the add copper II sulfate
if there is no protein the solution remains blue
f protein is present solution turns purple
37
What is diffusion?
The net overall movement of particles from an area of higher concentration to an area of lower concentration.
38
What is osmosis?
The movement of water molecules across a partially permeable membrane, froa region of high water concentration to low water concentration.
39
What does active transport work against?
A concentration gradient.
40
What is active transport?
The movement of particles across a membrane against a concentration gradient using the energy transferred during respiration.
41
What happens when there is a higher concentration of nutrients in the gut than the blood?
The nutrients will naturally diffuse into the blood.
42
What do chromosomes contain?
Genetic information.
43
What are the 4 stages of mitosis?
Prophase, Metaphase, Anaphase, Telophase
44
Prophase stage?
chromosomes condense and get shorter and fatter, membrane around nucleus breaks down and chromosomes lie free in the cytoplasm
45
Metaphase stage?
Chromosomes line up at the centre of the cell
46
Anaphase stage?
Cell fibres pull the chromosomes apart and 2 arms of each chromosome of to opposite ends of the cell
47
Telophase stage?
membranes form around each set of chromosomes these become the nuclei of 2 new cells, the nucleus divides
48
What happens at the end of mitosis?
2 new daughter cells are produced.
49
True or False are the daughter cells genetically identical haploid cells?
False they are two genetically identical diploid daughter cells.
50
What else are the cells identical to?
The parent cells.
51
What is cell differentation?
the process by which a cell changes to become specialised for a job.
52
How is cell division done?
Via mitosis
53
What is cell elongation?
The process by how plants grow, this makes cells bigger.
54
What sort of molecules are proteins, lipids and carbohydrates?
Big molecules
55
some food we eat have molecules to big to pass through walls in our digestives systems how do they get through?
Digestive enzymes break them down and make them smaller and more soluble molecules. These easily pass through and get absorbed into the bloodstream.
56
How do plants store energy?
In the form of starch.
57
What do plants do when they need energy?
They get enzymes to break down the starch into smaller molecules that acn be respired so energy can be transfered into cells.
58
What do carbohydrases do?
they convert carbohydrates into simple sugars.
59
What does proteases do?
They convert proteins into amino acids
60
what do Lipases do?
They convert lipids into glycerol and fatty acids.
61
How can carbohydrates be synthesised?
By joining simple sugars together
62
What is glycogen synthase?
An enzyme that joins together lots of chains of glucose molecules to make glycogen.
63
How are proteins made?
by joining amino acids together
64
How does all growth in animals occur?
Via cell division
65
How do plants tend to grow?
Via cell elongation
66
What controlls the rate at which cells divide?
the chemical instructions inside a cells gene.
67
What happens if a gene that controlls division alters?
The cell could start dividing uncontrollably.
68
What happens if a cell starts to divide uncontrollably?
a mass of abnormal cells will occur this is called a tumour.
69
What happens if a tumour invades and destroys surrounding tissues?
Cancer is formed
70
What is used to mointor weight and growth?
percentile charts
71
where are stem cells typically found?
in human embryos can be found in adult bone marrow too.
72
What does meristems contain?
Plant stem cells
73
What can we sometime cure sickle cell anaemia with?
we can use bone marrrow transplant. This contains new adult stem cells which will produce red blood cells.
74
What can we use stem cells for?
We can use them for replacing any cells that have been damaged by disease or injury. This is a big deal as it creates a potential for new cures.
75
What does the cerebrum do?
The largest part of the brain and has two parts the right hemisphere controls the muscles on the left hand side and the left hemispehre controls the muscles on the right hand side. different parts ave different possibilities this includes in movement, intelligence, memory, language as well as vision
76
What is the cerebellum responsible?
Muscle coordination and balance of the body.
77
Whats the job of the medulla oblongta?
It controls uncosncious activities like breathing and your heart rate.
78
Explain a CT scanner?
It uses x-rays to produce images of the brain and the scan shows the main structure of the brain but not the functions, However this changes when part of the brain is damaged the function of that part is able to be worked out
79
Explain a PET scanner?
More fancy than a CT scanner, uses radioactive chemicals that show which part of a brain is active when the person is in the scanner, they are very detailed and used to investigate both the structure and function of the brain in real time finally can show areas of the brain that are unactive or not meant to be active so can help identify disorders that change the brains activity, PET show the recution when compared to a normal brain.
80
What does CNS stand for?
central nervous system
81
How does the CNS work?
1) a stimulus is detected by receptors, info turned into an electrical impulse and sent along the sensory neurons, to the brain and spinal cord, they respond and send impulses to the relay neurons, then a message is sent to an effect by the motor neuron and response either contracting a muscle or gland secreting a hormone.
82
What are the three types of neurons?
They are sensory neurons, motor neurons and relay neurons.
83
How does a sensory neuron work?
A long dendron carries nerve impulses from receptor cells to the cell bodies, (located in middle of neuron) a short axon carries nerve impulses from the cell body to the CNS.
84
How does a motor neuron work?
Short dendrites carry nerve impulses from the CNS to the cell body, one large axon carries nerve impulses from the cell body to effector cells.
85
How does a relay neuron work?
Short dendrites carry nerve impulses from sensory neurons to the cell body, an axon carries nerve impulses from the cell body to motor neurons.
86
what connects neurons?
Synapses connect neurons
87
How do reflexes help prevent injury?
1)(bee sting scenario) reflexes are automatic and rapid, they reflex arc goes through the spine and into the unconscious part of the brain, when a stimulus is detected by receptors and impulses are sent along sensory neuron to the CNS. When it reaches the synapse the sensory and relay neuron trigger neurotransmitters to release these are sent along the relay neuron. When it reaches the synapse between the relay and motor neuron the same thing happens but along the motor neuron. these travel along the motor neuron till it reaches the effector (either a muscle or gland) this makes the muscle contract and move (in this scenario) as you don't think about doing this it is quicker then other reactions.
88
How do reflexes help protect the eye?
Light receptors in eye detect bright light send message along sensory neuron to brain, message travels along relay neuron and a motor neuron telling circular muscles in the iris to contract.
89
What are the 7 main parts of the eye?
Iris, lens, retina, rods, cones, the optic nerve and pupil
90
What jobs does the iris have in the eye?
controls amount of light going in the pupil
91
What jobs does the lens have in the eye?
refracts light focusing it onto the retina
92
What jobs does the retina have in the eye?
Light sensitive and is covered in rods and cones
93
What jobs do the rods have in the eye?
sensitive in dim light can't see colour
94
What jobs do the cones have in the eye?
sensitive to colour not good in dim light
95
What jobs does the optic nerve have in the eye?
carries electrical impulses from receptors to the brains
96
What does the lens do to look at objects in the distant?
ciliary muscles relax allowing suspensory ligaments to be pull tight, the lens becomes less round so light isn't refracted as much.
97
what does the lens do to look at objects close up?
Ciliary muscles contract which slackens suspensory ligaments, this makes the lens in a more round shape so light is refracted more.
98
What is the problem with long sighted people?
Unable to focus on nearby objects. The lens isn't the right shape and doesn't bend the light enough the eyeball may also be too short. Light from objects close by is brought into focus behind the retina. Can be fixed with glasses or contact lenses. Should be a convex lense to fix it.
99
What is the problem with short sighted people?
Unable to focus on objects in the distance, occurs when the lens is wrong shape and bends light too much, eyeball may be too long. Light on distant objects is brought into focus in front of the retina. Use glasses or contacts, concave lens to correct this.
100
what is the problem with colour blinded people?
Caused when cones in the retina don't work properly, no cure for it as cone cells cannot be replaced. most common disorder is red-green colourblind
101
What is a cataract?
Cloudy patch on the lens.
102
What does a cataract do?(something to do with the eye)
A cataract stops light from being able to enter the eye normally, people with this are likely to have blurred vision or make colours look less vivid and have difficulties seeing in bright light,
103
How can a cataract be treated? (hint: eye)
replaces the faulty lens and puts a new artificial lens in its place.
104
What is sexual reproduction?
Sexual reproduction is where genetic information from two organisms (father and mother, (sperm and egg)) combine to produce offspring which are genetically different to their parent.
105
What is the difference between a haploid cell and a diploid cell?
a haploid cell or known as a gamete only contains half the number of chromosomes of a normal cell, A cell with the full amount of chromosomes are called diploid cells
106
What is the difference between a haploid cell and a diploid cell?
a haploid cell or known as a gamete only contains half the number of chromosomes of a normal cell, A cell with the full amount of chromosomes are called diploid cells
107
What happens at fertilisation?
a male gamete fuses with a female gamete to produce a fertilized egg or known as a zygote. the zygote ends up with a full set of chromosomes, the zygote undergoes cell division and develops into an embryo.
108
What is the difference between meiosis and mitosis?
Both are cell division but mitosis doesn't reproduce identical cells
109
What are the steps for meiosis?
1) in the 1st division chromosomes line up in pairs at the centre of the cell, one is from father on is from mother. Next the pairs are pulled apart so each cell only has one copy of each chromosome. Each new cell has a mixture of the mothers and fathers chromosomes this creates genetic variation. The second division has the chromosomes line up again. arms of chromosomes are pulled apart. This leave you with 4 haploid daughter cells, all genetically different
110
Who does asexual reproduction how many parents are needed?
some plants - One parent
111
What are advantages of asexual reproduction?
can be completed very quickly as reproductive cycle is fast, bacteria like e.coli divides every half hour, only one parent is required
112
What are disadvantages of asexual reproduction?
No genetic variation in offspring - population will all be the same so one getting a disease will affect all future generations. whole population could die because of different climates.
113
What are advantages of sexual reproduction?
everyone is different because of genetic variation, so conditions change so will species, leads to evolution and natural selection
114
What are the disadvantages of sexual reproduction?
Takes more time and energy then sexual reproduction, need to find and attract mates, two parents needed one provides sperm one provides egg.
115
What is a DNA strand made up of and what are the shapes?
Phosphate - oval, sugar - pentagon, base - rectangle
116
What shape is DNA?
It has a double helix shape.
117
How do you extract DNA from fruit?
Mash up strawberries and put in beaker with salt and detergent., detergent breaks down cell membranes releasing DNA, salt causes DNA to stick together, Filter into a test tube to remove froth, big pieces of strawberries or insoluble pieces.
add ice-cold alcohol to filter mixed solution, appears as a string white precipitate as not soluble in cold alcohol, can be taken out with glass rod
118
What does the order of bases in a gene decide?
It decides the order of the amino acids.
119
How many amino acids are in a base?
3 (TCG)
120
What are the complimentary base pairs and which other base do the connect to?
A, T, C, G A-T C-G
121
What is a mutation in genes?
When a genetic variant is produced, creates a different amino acids meaning a different code has been created.
122
What are the two stages for protein to be created?
Transcription and Translation
123
Where is protein made and by what?
Protein is made in cytoplasm by sub cellular structures called ribosomes
124
What are the steps in Transcription?
1)RNA polymerase binds to a non coding dna in front of a gene,
2) the strands unzip and the RNA moves along one of the strands of DNA.
3)using the coding DNA as a template mRNA is made, base pairings makes sure this is complimentary.
125
What are the steps in Translation?
Amino acids are brought to the ribosome by tRNA
the order they are brought matches base triplets, in mRNA base triplets also known as codons.
Part of the structure of tRNA has an anti codon this is complimentary to the codon of the amino acid. This makes sure amino acids are brought in correct order. Ribosome joins them together creating a polypeptide.
126
What happens if a mutation occurs during transcription?
Affect how RNA binds, this affects how much information is transcribed and how much protein is produced,
127
What was Mendel's genetic experiment and what did he discover?
He cross bred two pea plants of different heights and examined their offspring. Then bred two of the tall offspring. He found out for every three tall pea plants he got 1 dwarf plants, showing dominant and recessive alleles and learnt about hereditary units.
128
What 3 conclusions did Mendel come to from his pea experiment?
1)hereditary units determine characteristics in plants
2)Hereditary units are passed on from offsprings, one from each parent
3)Hereditary units are either dominant or recessive, dominant over powers recessive genes.
129
Flick card don't know a question but useful info
if an organism has two dominant alleles the gene will be dominant, if one dominant and one recessive will be dominant, needs both alleles to be recessive for gene to be recessive.
130
What is your genotype?
The combination of alleles you have
131
what is your phenotype?
The characteristics you have, determined by your alleles.
132
USE PUNNETT SQUARES FOR GENETIC DIAGRAMS
USE PUNNETT SQUARES FOR GENETIC DIAGRAMS
133
How many pairs of matched chromosomes are in a human body?
23 last pair is either XX or XY, this determines if you are male XY or female XX 50:50 ratio ALWAYS so could have 100 children and all be boys
134
what type of allele is cystic fibrosis and 1 in how many people carry it?
it is a recessive allele with 1 in every 30 people having it
135
What carries more genes the X or Y chromosome?
The X chromosome carries more genes as it is bigger.
136
What is the most common colour blind disease?
Red-green colourblind, much rarer in women as they needed to recessive alleles as the colour blind is on the X chromosome so if men get the infected X chromosome they are colourblind.
137
How many potential blood types are there and what are they?
O, A, B and AB with three alleles I^O I^A and I^B
A and B are codominant so combine if someone has both. I^O is recessive so need to I^O to be O blood group
138
What are the two reasons for variation within species?
Genetics and environment, genetics is caused because of different alleles creating different phenotypes,, also mutations create new alleles and because of sexual reproduction results in alleles combining.
Environmental is because of adaption to environments and changing to survive and live their to the bests of its ability.
139
Explain genetic mutations?
They are changes to the base sequence of DNA, result in an allele or different version of the gene, can have slight altercations like long hair or short hair or could have a big effect on phenotype like with cystic fibrosis.
140
What are drawbacks of The Human Genome project?
Increased stress if people know they could get a deadly disease later in life.
People with genetic problems forced to not have children so gene isn't passed on in future generations
discrimination - people may be less likely to higher people if they could get a serious disease or less likely to get life insurance so the company won't have to pay out
141
What is the Human Genome Project?
The idea to find every single human gene, started in 1950 and completed in 2003 with around 20,500 genes having been found, now they figure out what they do and 1,800 have helped identify diseases.
142
How has the Human genome project helped medical applications?
helps predict and prevent diseases as can be seen in gene and can trace problems and get earlier treatments.
helps testing and treatment -inherited disorders fault of one or more faulty alleles, has helped identify genes and alleles that could cause disorders
New and better medicines - can help design and tailor drugs for genetic variations and how they react to current drugs.
143
define healthy
a state of complete physical and mental and social well being
144
What are the two types of diseases?
Communicable or non-communicable
145
define Communicable
communicable is disease that can spread by individuals, thorugh water, air, bodily fluids.
146
define Non-Communicable
can not be transmitted thorugh individuals like cancer or heart disease
147
What is a pathogen and what are the different types?
it is an organism, examples are viruses, bacteria, fungi and protists
148
what are the communciable disease needed for exams?
Cholera - bacterium, diarrhoea, water
tuberculosis - bacterium, coughing and lung damage, through air
malaria, protist,damage to red blood cells and liver, mosquitos
stomach ulcers- bacterium, stomach pain, nausea and vomiting, oral tranmision swallowing contaminated substances
ebola- virus, fever with bleeding (haemorrhagic) via bodily fluids
cholera ash dieback- fungus infects ash trees, leaf loss, carried through air by wind.
149
what are the two pathways which a virus can reproduce?
The lytic pathway and lysogenic pathway.
150
what are the steps of the lytic pathway?
1)virus attaches to a specific host cell and injects genetic material into cell
2)virus uses proteins and enzymes in host cell to replicate genetic material
viral components assemble
151
what are the steps lysogenic of the pathway?
1)injected genetic material put into genome of DNA
2)viral genetic material replicates every times host cell divides, virus dormant and no new one is made
3)eventually a chemical tiggers the viral genetic material to leave the geneome and enter the lytic pathway.
152
What are the 2 required STD's you need to know?
Chalmydia which is a bacteria and HIV which is a virus
153
how does HIV develop into AIDs?
This is when the immune system deteriorates and then fails increasing vunerability to infections by other pathgens, use a condom and if a drug user don't share needles
154
How does a waxy cuticle protect a plant?
act like a barrier to prevent pathogens entering, stop water collecting on leaves reduce risk of pathogens passed by water the cell wall is a physical barrier to prevent any pathogens that make it past the waxy cuticle
155
what chemicle defenses do plants have to prevent themselves from pathogens ?
Quinine comes from bark from a cinchona tree (used to treat malaria) aspirin pain and fever relieve, found in bark and leaves of willow trees. chemicals kill bacterial and fungal pathogens and also stop pests.
156
What 2 ways can pathogens be detected in a lab?
detecting antigens and detecting dna
157
How are antigens detected?
Pathogens have unique molecules on their surface, antigens form a particular pathogen and this will be present in the infected plant, this can be detected in a sample of tissue.
158
How is DNA detected ?
If a plant is infected with a pathogen the DNA will be present in the plant's tissue. scientists have techniques that allow them to detect small amounts of pathogenic DNA.
159
What physical barriers does the human body have?
skin - is a barrier if it gets damaged blood clots quickly and seals cuts to keep microorganisms out. Hairs and mucus - in your nose trap particles that could contain pathogens.
cells in trachea and bronchi produce mucus this traps pathogens, other cells that line the trachea and bronchi have cilia, these are hair like structures which waft mucus up to the back of the throat where it can be swallowed
160
What chemical barriers does the human body have?
Stomach produces hydrochloric acid this kills most pathogens.
eyes produce lysozymes (tears) these kill bacteria on the surface of the eye.
161
How does the immune system attack pathogens?
every pathogen has unique models, when the B-lymphocytes come across an antigen on a pathogen, the produce proteins called antibodies, these lock on to the pathogen so it can be found and destroyed by other white blood cells. they are specific and only lock onto certain pathogens, after are produced rapidly and flow around the body to find similar pathogens.
162
What are memory lymphocytes?
when a pathogen 1st enters body there is a low response time, as not many B-lymphocytes can make antibody, overtime the body produces enough of the right antibody to overcome infection, as well as these antibodies memory lymphocytes are produced and these remain in the body for ages incase the disease returns. making the person immune
163
How does immunisation help stop infections?
Body is given a dead or inactive pathogen, these have antigens but can not harm the body, this means the person is given the disease but won't be affected and the body can produced antibodies and have memory fo the disease so the person becomes immune.
164
What are cons of immunisation?
Not 100% effective and will not always work, while bad reactions are rare they could happen.
165
What are monoclonel antibodies?
they are clones of b-lymphocytes, antibodies are all identical and will only target one specific antigen
166
How does monoclonal antibodies work in pregancy tests?
HCG (a hormone) is found urine of pregnant women, pregnancy sticks detect this. Where you pee on the stick has blue beeds attatched, test strip has more hormones with antibodies stuck onto it, if pregnant and wee the hormone bind to the antibodies on blue beeds, the urine moves up the stick the bind to the anitobodies on the strip and the blue beeds get stuck turning it blue. If not pregnant the beeds move to the end of the stick and do nothing.
167
How can monoclonal antibodies diagnose cancer?
cancer cells have protein on cell membranes not foudn on normal cells, they diagnose cancer by labellung the antibody with radioactive elements, these get given through a drip, they go in via blood and get carried round the body, they bond to the tumour markers when they come into contact with a cancer cell. a picture of the patients body is taken and a bright spot lights up where the cancer is.
168
How can monoclonal antibodies target cancer cells?
once again gven through the drip, the antibodies are target specific cells as they only bind to the tumour markers, the drug attatched to the antibody kills the cancer cell but not any normal cells, other cncer treatment can affect body cells like radiotherapy, has lower side effects than radiotherapy.
169
How do monoclonal antibodies detect blood clots?
when blood clots proteins in blood join together to form a solid mesh, monoclonal antobodies have been made to attach to these, a radioactive element is attacthed and when injected into the blood a picture can be taken and it highights where the blood clot if there are any.
170
What is the first stage of developing drugs?
first a drug needs to be discovered in a lab, after it has to be developed which nvolves preclinical and clinical testing
171
what is preclinical testing?
Preclinical tetsing is when drugs are first tested on human tissue and cells, however this can not be show the affect on multiple or whole body systems so then we use live animals like rats and bunnies, , this is to ensure that the drug works, see how toxic it is and to help find the best do sage
172
What is clinical testing?
Clinical testing is the next step in the development of the drug, human voluntters get used to see harmful side effects on a normal working body, if there a good results from this then people with the illness get used to ind optimum dosage with the least amount of side effects, they use a blind and double blind testing to enhance results. then the drug gets approved before used to treat patients.
173
How do you grow bacteria in a lab?
Bacteria are cultured in a growth medium, these contain carbs, minerals, proteins, vitamins, the growth medium uses agar jelly, this is because it helps form visible colonis on the surface.
174
What is the investigation for the effect of substances on bacterial growth?
1) on the plastic dish divide it into 3 sectors, open the dish at an angle facing the flame put in the liquid in and spread it around the circle, then in each sector put the antibiotic in. Make sure to sterilise the equipment between each antibiotic. once all antibiotics are in close the dish and tape it, then put in a fridge at 25 degrees celsius.
175
What is aspetic techniques?
its killing any unwanted organisms this can be done by using an autoclave which uses steam at high pressure and temperature to kill the micro organisms or passing it rhough a hot flame.
176
What are some risk factors of non cumminacable diseases?
smoking, drinking alcohol, lack of exercise high saturated fat diets.
177
What is the equation for BMI?
Weight(Kg)/height(m^2)
178
What is the equation for waist to hip ratio?
waist circumference/hip circumferance
179
What are statins?
a drug that reduce amount of cholesterol slows down fatty deposits , can cause aching muscles and liver damage
180
what are anticoagulants?
reduce risk of blood clots, can cause excessive bleeding when peson injures.
181
what are antihypertenisves?
reduce blood pressure, prevent damage to blood vessels and can cause side effects of headaches and fainting
182
How does bacteria prove evolution?
random mutations in DNA create new alleles.
183
What was classification?
all living organisms come from a common ancestor we are all related in some way
184
how old is Ardi?
4.4 millions years old mix of human and ape, feet structure suggest climbed trees, brain size of a chimp
185
how old is lucy?
3.2 million years also human-ape but more human, large brain the ardi, feet showed walked upright.
186
how old are hominids?
1.6 million years old, human and ape mix, mor ehuman, short arms, long legs, similiar size brain to a human
187
how do tools show human evoloution?
1st there was pebble tools made from hitting rocks together to make sharp flakes to scrape meat of bones or crack bones open, then rocks got sculpted into shapes to make some effective tools like axes, then tools devloped to being pointed and were wooden tools, finally flint tools were being used like arrowheads, fish hooks
188
What can bone structure tell us about evoloution?
similairity in structre from pentadactyl limbds shows a common ancestor as if they al evolved from different ancestors they wouldn't have a similiar bone structure.
189
What are the 5 kingdoms?
Animals, plants, fungi, prokaryotes and protists
190
How is selective breeding useful?
it means that the best characteristics an be passed on meaning animals will increase in size and more food will be gotten off of them
191
What are disadvantages of selective breeding?
reduces the gene pool and means animals aemore closely related, increases health problems and risk of inheriting harmful genetics. and if a disease appears due to little variation all could get the disease and little resistance would grow from it.
192
How do you grow plants using tissue culture?
choose wanted plant, remove several small pieces of tissue from the plant, you get the best results if you take tissue from fast-growing root or shoot tips. then in a growth medium which contains the right nutrients and hormones you grow the tissue, the biome is sterilised so the plants don't get affected by microbes. , when the pants produce shoots and roots they can be transported.
193
How do we use animal tissue in reasearch?
1)sample the tissue needed for study, seperate the cells using enzymes, put in a culture vessel and bathed in a growth medium helping them grow and multiply, after a while the cells are placed into seperate vessels to grow further, once grown can be stored for later use.
194
what are restriction enzymes
and ligase?
restriction enzymes recognise specific sequences of DNA thepieces of DBA get left with stikcy ends.
Ligase enzymes are used to join two pieces of DNA together at their sticky ends.
195
What are plasmids and viruses?
Plasmids are small ciruclar molecules of DNA that can be transferred between bacteria, viruses insert DNA into the organism and they infect it.
196
How do we use vectors to insert DNA into other organisms?
1)the DNA you want to insert is cut out with a restriction enzymes, the vector DNA gets cut open using the same restricion enzyme, The vector DNA and DNA getting inserted are left with sticky ends., they get mixed with lages enzymes. the ligase joins them creating recombiant DNA. which gets inserted into other DNA molecules, these cells can now use the inserted gene.
