Science Additional - Biology 3

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  • Created by: alliyah14
  • Created on: 13-01-16 13:49
What features does an animal cell have?
The following cell structures are found in most animal cells: Nucleus, Cytoplasm, Cell membrane, Mitochondria & Ribosome.
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What features does an plant cell have?
Nucleus, Cell wall, Cytoplasm, Vacuole & Cell membrane.
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What features does a bacteria cell have?
Cell membrane, Single strand of DNA, Cytoplasm & Cell wall.
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What does a Nucleus contain?
A nucleus contains DNA in the form of chromosomes.
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What is a Cytoplasm in terms of cells?
Gel-like substance where most of the cells chemical reactions happen.
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What controls what goes in and out of a cell?
A cell membrane holds imformation together and controls what goes in and out of the cell.
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Where are proteins synthesised?
Ribosomes are where proteins are synthesised.
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Where does respiration take place in a cell?
Mitochondria is where most reactions take place that involve respiration. Cells that need lots of energy contain many mitochondria.
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What supports the cell?
The Cell wall is made of Cellulose, it supports the cell.
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In a plant cell where does photosynthesis take place?
In the Chloroplasts is where photosynthesis happens.
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Where is a cell snap in a cell?
A vaculoe is a relatively large structure that contains cell snap, a weak solution of sugar and salts.
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Does a bacteria cell have a Nucleus, Chloroplasts or a Mitochondria?
Bacteria cells have none of the following.
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What are Chromosomes made of?
Chromosomes are long molecules of coiled up DNA.
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What are genes in terms of DNA?
The DNA is divided up into short sections called genes.
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What are nucleotides?
DNA is a double helix (a double-stranded spiral). Each of the two DNA strands is made up of lots of small groups called nucleotides.
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What is a base in terms of DNA?
Each nucleotide contains a small molecule called bases. DNA have 4 bases.
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Whare are the four Bases in DNA and which match with each other?
A,C,G,T - A matches with T & G matches with C. This is called complementary base pairing.
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What did Watson and Crick do?
They were the first to model DNA. They used data from other scientists and data to understand DNA.
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Why did Watson and Crick use x-ray data?
They used x-ray data to show that DNA is double helix that is formed using two chains wound togeher.
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How does new cells still have the full amount of DNA?
DNA copies itself everytime the cell divides, so that each new cell has the full amount of DNA.
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How does DNA copy itself?
In order for DNA to copy itself the double helix slipts to form two single strands. New nucleotides then join using complementary base-pairing. This makes an exact copy and results in two double stranded DNA molecules.
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What is protein synthesis?
DNA controls the prodction of proteins (protein synthesis) in a cell.
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What is a Gene?
A section of DNA that codes for a particular proteins is called a gene.
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What are proteins made of?
Protein are made of amino acids, each protein has a specific amount of amino acids and order.
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What decides on the order of the amino acids?
It's the order of the bases in a gene that decides the order of the amino acids.
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How does the body generate unique proteins?
Each gene contains a different sequence of bases - which is what allows it to code for a unique protein.
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Where are proteins made?
Proteins are made in the cell Cytoplasm.
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What makes proteins?
Proteins are made by tiny structures called ribosomes.
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What is mRNA function?
mRNA carries the code to the Ribosomes. It acts as the messenger between the DNA and Ribosomes.
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Why can't the DNA go directly to the Ribosomes?
DNA must stay in the nucleus as its too big to exit the cell nucleus.
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Why does DNA need to go to the Ribosomes?
DNA must travel to the Riboosomes in order to make protein.
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How does mRNA do it job?
mRNA copy the DNA and carries the code to the ribosomes.
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How does DNA control a cell?
DNA controls a cell by conrolling protein production. The protein in a cell affects how it functions.
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What does the proteins produced affect in the body?
Some of them determine the cell structure, whereas others control the cell reaction (like enzymes).
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Why does different types of cells have different functions?
Different types of cells have different functions as they make different proteins.
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What function does 'carrier molecules' have?
Ìts a protein that is used to carry small molecules around the body. E.g. Haeomglobin found in red blood cells.
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What function does 'hormones' have in terms of proteins?
This protein is used to carry messages around the body. E.g. Insulin is a hormone released into the blood to regulate the blood sugar.
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What function does 'structural proteins' have on the body?
Structural proteins are made to be physiclly strong. E.g. collagen is a strutcural protein that strenghtens connective tissues.
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Whta types of reactions are taking place in a cell?
Cells have thousands of chemical reactions taking place like respiration, photosynthesis and protein synthesis.
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Why can't you raise temperatures of the body to speed up reactions?
By raising temperatures this would speed up useful reactions but also unnwanted reactions too. Also if a cell is under high temperatures it could become damaged.
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What do Enzymes act as?
Living things produce enzymes which act as a BIOLOGICAL CATALYST.
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What is a Biological Catalyst?
A biological catalyst is a subtance that speeds up reactions without being used itself.
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Do different biological reactions have different enzymes?
Yes, every differnt biological reactions has its own enzymes specific for its reaction.
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What does chemical reactions involve?
Chemical reactions usually involve things being split or joined together.
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What is a substrate?
The substrate is the molecule changed in the reaction.
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What is an active site on a enzyme?
Its the part where an enzyme joins on to a substrate to catalyse the reaction.
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What is the lock and key mechanism?
If the substrates shape doesn't fit the active site it won't catalyse, this is known as the lock and key mechanism.
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What does the enzyme change into after a reaction is complete?
Trick question! The enzymes remain the same after a reaction as a catalyst is not used during a reaction.
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What happens to the rate of the reaction when the temperature is changed?
Changing the temperature will change the rate of reaction in an enzyme-catalysed reaction.
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What take place when a reaction is under high temperatures?
A high temperature will increase the rate of reaction at first as the substrate particles will have more energy and will be more likely to collide with enzymes quicker. This will lead to high collision rates.
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What will take place if a reaction happens under lower temperatures?
Lower temperature will have the opposite effect, the substrate particles will have less energy and will be slow. This leads to the enzymes and the substrate particles colliding together slower. Overall resulting in a lower rate of reaction.
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What will happen if the temperatures are too hot?
If it get too hot the bonds holding the enzymes together will break. This means it will lose shape and no longer function.
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What is denaturing?
Denaturing is when the temperatures are too hot that the enzyme can no longer work or function. Its change in shape is irreversible.
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What is the optimum temperature?
Every enzyme has a maxium optimum temperature where the reaction is at its fastest. This is the temperature just before the enzyme starts to denature.
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If the pH is too low or high what does it have an effect on?
If its to low or high it interferes with the bonds holding the enzymes together and leads to them denaturing.
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What does the Q10 show us?
Q10 values shows how rate of reaction changes with temperature.
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What is the Q10 equation?
Rate at higher temperature / Rate at lower temperature.
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If the Q10 = 2 what does it mean?
That between the higher and the lower temperature the rate has doubled.
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What is a a mutation?
A mutation is a change in the DNA base sequences.
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What happens if a mutation takes place in a gene?
It could stop production of the protein that the gene usually makes or the gene could create a incorrect protein.
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What happens if a gene creates the wrong protein or no protein?
It would be a diaster specificlly if the enzyme was important.
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What happens if a mutation occurs in reproductive cells?
The offspring could develop abnormally or die at an early stage.
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What happens if a mutation occurs in a body cell?
The cell will multiply in an uncontrolled way and reach other parts of te body. This is cancer.
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What happens rarely if a new protein is created due to mutations?
Sometimes it could be a benefit and therefore leading to an advantage over the population. This then gets passed on to their offspring.
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What do you need to be exposed in order to have your chances of mutation increased?
Subtances that increase chances of mutations if exposed to them is ionising radition and ceratin chemicals like carcinogen (what cigareettes contain) and mutagens.
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What is wrong with single-celled organisms?
Nothing! They are pretty successful just look at bacteria.
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What are some advantages of being multicellular?
They are larger which is good as they can travel further and protect themselves from getting eaten etc.
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What is cell differentiation?
This where unlike singe-cells multicellulars can do lots of different jobs around the body. As single cells just do one job mulitcellulars do more complex and diffcult functions. E.g. one multicellulars can carry oxygen & deliever the right nutrients
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What must a multicellular cell have?
Being multicellular means that an organism must have a specialised organ system.
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What does Mitosis do?
Mitosis makes new cells for growth and repair.
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How does Mitosis work?
Mitosis is when a cell reproduces itself by splitting to form two identical offspring.
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Where do Mitosis take place?
Mitosis occurs all around the body in order for growth and repair to take place.
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Why does the body need Mitosis?
When the body creates identical cells its an advantage because then the body can replace the old and worn out cells with cells that can grow and repair damage within the body.
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What happens at the start of Mitosis?
Before Mitosis starts, the DNA in the cell is replicated.
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What are double-armed chromosomes?
The DNA coils into Double-armed chromosomes, these arms are exact copies of each other - they contain exactly the same DNA.
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What lines up at the centre of the cell during Mitosis?
The chromosomes line up at the centre of the cell and then divide as cell fibre pull them apart.
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What goes to opposite ends of the cell during Mitosis?
The two arms of each chromosmes go to opposite poles (ends) of one cell. Membranes form around each of these two different sets of chromosomes.
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What happens to the cytoplasm during Mitosis?
The cyctoplasm divides, to form two new cells containing the same exact DNA in each new cell.
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What needs to occur before the two new cells can divide again?
Once you have two new cells that are genetically identical to each other, before these can divide again the DNA has to replicate itself to give each chromosome two arms again.
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What is Meiosis?
Meiosis is another form of cell division - it creates Gametes.
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What are Gametes and where are they found in the body?
Gametes are found in the ovaries and testes. Gametes are the sex cells - eggs and sperm.
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What is Diploid?
The body cells of a mammel are diploid. This means that each cell has two copies of chromosomes in its nucleus. One chromosome is from their mother and the other is from their father.
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What is hiploid?
Hiploid is where there is only one copy of chromosomes in there cell. This is so that when the egg and the sperm combanie, they'll form a cell with the diploid number of chromosomes.
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How does Meiosis start?
Meiosis starts the exact same way as mitosis - the DNA replicates itself and curls up to form double-armed chromosomes.
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What happens in the first division of Meiosis?
In the first division these pairs split up (46 chromosmes to 23).
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How many cells does Meiosis generate after the process?
Once Meiosis is complete you end up with four new cells, two after the first division and four after the second division.
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Why in Meiosis are the cells genetically different?
The cells are genetically different from each other because the chromosomes all get shuffled up during meiosis and each gamete only get half of them at random.
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What is zygote?
At fertilisation male and female gamtes combine to form a diploid cell. This is called Zygote.
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How has sperm adapted to its function?
Sperm are small and have long tails to swim. Also have lots of Mitochondria to swim far. They also have acrosome at the front of their head to release enzymes to digest their way through the membrane.
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What is the difference between Animal and plant growth?
Animals stop growing, plants can grow continuously.
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What type of cells can turn into different types of cells?
Stem cells can turn into different types of cells.
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What is Differentiation?
Differentation is the process by which a cell changes to become specialised for it's job.
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What are Stem Cells?
They develop into different types of cells, tissues and organs depending on what instuctions are given.
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Where are Stem Cells found?
Stem cells are found in early human embryos. They have the potential to turn into any kind of cell at all.
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Where are Adults Stem cells found?
Adults also have stem cells, but they're only found in certain places, like bone marrow. However these aren't the same as embryonic cells as they can't turn into any cell.
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How does Stem Cells cure Diseases?
As Bone marrow contains stem cells if someone had blood disorders they would have a transplant to ensure stems get into their body to create new blood cells to replace the faulty ones.
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Why do scientists extract human embryos?
As they contain a lot of stem cells scientists extract the cells so they can grow them. They think that this will grow tissues to treat medical conditions.
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Why do some believe that human embryos should not be used for cell research?
Some people are aganist cell research because they feel that human embryos are potential life therefore killing a human life. However some think that helping the living is more important than potential humans.
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Give an agument in favour of cell research.
The embryos used are usually unwanted ones from fertility clinics which would have probably of been destoryed anyways.
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Which countries fund and don't fund cell membrane?
There are number of 'stocks' of stem cells that scientists can use for researh. USA don't provide funds where as the UK do however have scrict guidelines.
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How can we measure growth?
Methods to measure growth: Length - Just length or height, Wet Mass -Is just the Mass, & Dry Mass - Drying out the organism before weighing it.
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Advantages and disadvantages of length.
Advantages: Easy to measure. Disadvantages: It doesn't give any other information nor tell you about the width.
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Advantages and Disadvantages of Wet Mass.
Advantages: Easy to measure. Disadavntages: Wet mass is very changeable.
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Advantages and Disadvantages of Dry Mass.
Its not affected by the amount of water in a plant nor the food. Disadvantage: You have to kill the animal to work out the Dry Mass.
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Which measure of growth is the best mehod?
Dry Mass is actually the best measure of growth in plants and animals - its not affected by changes in water content and it tells you the whole size.
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What are the different phases of Human Growth?
The phases are: Infancy, Childhood, Adolescence and then Maturity & Old age.
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When does a person stop growing?
Growth stops when a person reachs adulthood.
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Does the body grow consitantly?
No, Certain parts of the body grows faster or slower than others.
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Is Respiration breathing in and out?
No, Respiration goes in every cell in your body. It's the process of relesing energy from glucose.
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Can Respiartion be used directly on a cell?
No, respiration is used to make a substance called ATP.
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What does ATP do?
ATP acts as an energy source for many cell processes and transfers energy to where it's needed in a cell.
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What is respiration controlled by?
Respiration is controlled by enzymes.
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What is the rate of respiration affected by?
Rate of respiration is affected by both temperature and pH.
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What are the two types of Respiration?
The two types of Respiration are Aerobic and Anaerobic.
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What is Aerobic Respiration?
This is what happens when there is plently of oxygen and it's the most efficient way of releasing energy from glucose. It's what we use most of the time.
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What is the word equation of Aerobic Respiration?
Glucose + Oxygen -> Carbon Dioxide + Water (+ Energy)
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What happens when rate of respiration increase?
When Respiration rate increases, both oxygen consumptions and carbon dioxide production increases.
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What can be used to estimate metabolic rate?
The rate of oxygen consumption can be used to estimate metabolic rate (the amount of energy being used).
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What is Anaerobic Respiration?
Anaerobic Respiration Doesn't use oxygen at all and it keeps your muscles going when you're in a bad state.
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Why is Anaerobic Respiation not the best way to convert glucose to energy?
It's not the best way to convert glucose because it releases a lot less energy per glucose molecule than aerobic respiration.
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What does Lactic Acid do to your muscles?
The lactic acid builds up in the muscles, which gets painful and makes the muscles fatigued.
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When you stop exericsing why will you have oxygen debt?
You will need extra oxygen to break down all the lactic acid that's built up in your muscles and to allow aerobic respiration to begin again. This means you have to keep on breating hard for a while after you stop exercising to repay the debt.
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What is the word equation for Anaerobic Respiration?
Glucos -> Lactic Acid (+Energy)
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What is Respiratory Quotient?
It tells you whether someone is respiring Aerobically or Anaerobically.
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What does the figure 0.7 and 1 how about someones respiration in RQ?
The RQ is usually between 0.7 and 1 - this means that the person is respiring aerobically. If the RQ is greater than 1 then the person is respiring Anaerobically.
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What is Plasma?
Plasma is the liquid bit of blood. Plasma is yellow liquid which carries things around the blood.
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What does Plasma carry around the body?
Red blood cells, White Blood cells, Water, Digested Food, Carbon Dioxide, Urea, Hormones & Antibodies.
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What is the shape of Red Blood cells?
Red blood cells are small and bioncave shaped to give a large surface area to volume ratio for absorbing and releasing oxygen.
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What gives red blood cells it's colour?
Red blood cells contain haemoglobin, which gives the blood it's colour - it contains a lot of iron.
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What happens to the haemoglobin in the lungs?
In the lungs, haemoglobin combaines with oxygen to become oxhaemoglobin. In the body tissues the reverse happens to release oxygen in the cells.
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What is biconcave?
Biconcave is just a posh term for a round doughnut shape.
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What are Blood Vessels used for?
Blood Vessels are how blood gets around the body.
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What are the three types of blood vessels?
Arteries, Capillaries and Veins.
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What are Arteries used for?
They carry the blood away from the heart.
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What are Capillaries?
These are invovled in the exchange of materials at the tissues.
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What are Veins used for?
These carry blood to the heart.
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What type of pressure does blood flow through the arteries?
The heart pumps the blood out at high pressure so the artery walls are strong and elastic. The walls are thick compared to the lumen (the middle of the hole). They contain layers of muscle.
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What size are the Carillaries?
Arteries branch into capillaries. They are so tiny - you can't even see them.
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What are Carillaries function?
They carry blood really close to every cell in the body to exchange subtances with them. They have permeable walls, so substances can diffuse in and out. Also they supply food and oxygen and take away CO2 (Waste).
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What happens when capillaries join together?
Capillaries eventually join up to form veins.
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What type of pressure is blood under in the Veins?
In the Veins blood are under lower pressure so the walls aren't thick.
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Why do Veins have larger Lumen than Arteries?
To help the back flow despite low pressure.
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Why do Veins have Valves?
They have valves to help keep the blood flowing in the right direction.
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Why don't Arteries need valves?
The pressure in them is high enough to keep the blood flowing the right way.
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What is a double circulatory?
It's where the heart and the lungs are connect to the rest of the body.
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In the double circulatory system, what is the first system?
This is where the heart connects to the lungs. Deoxygenated blood is pumped to the lungs to take in oxygen. The blood then returns to the heart.
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In the double circulatory system, what is the second system?
This connects the heart to the rest of the body. The oxygenated blood is pumped around the body and then the deoxygenated blood returns to the heart to be pumped to the lungs again.
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What are the advantages of a double circulatory system?
Its very fast way of producing oxygen so therefore it can then ensure animals maintain a good body temperature.
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What is the Right side of the heart responsible for?
The right side is for deoxygenated blood.
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What is the Left side of the heart responsible for?
The left side is for oxgenated blood.
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In the right artium of the heart, where is deoxgyenated blood recieved?
The right artium of the heart recieves deoxygenated blood from the body through the Vena Cava.
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How does Deoxygenated blood leave the heart?
The deoxygenated blood moves throught the right venticle, which pumps it to the lungs via the pulmonary artery.
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What is the Vein called that lets Oxygenated blood into the heart?
The left artium recieves oxygenated blood is through the plumonary vein.
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What allows the oxygenated blood to move all around the body?
The oxygenatd blood moved through to the left ventricle, which pumps it all around the body through the aorta.
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Which Ventricle has a thicker wall? Left or Right?
The left ventriicle has a much thicker wall as it needs more muscle to pump blood around the whole body, whereas the right only pumps blood to the lungs.
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Name the Three Types of Valves in the heart?
The semilunar, Tricuspid and Bicuspid valve, which prevents backflow.
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Is the Tricuspid valve located on the Right or Left side of the heart?
Tricuspid valves are located on the Right side (Remember tRicuspid) and the Bicuspid valve is located on the left side. The semilunar valves are located on both sides.
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What is Selective Breeding?
Its when human artificially select the plants or animals that are going to breed and have their genes remain in the population, according to what we want from them.
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Why do people Selective Breed?
In order to gain the best features from an animal or plant: To gain maximum yield (meat, milk & grain), Good health and disease resistance & Other qualities like speed, attractiveness and temperament.
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What are some disadvantages of Selective Breeding?
It creates a gene pool (Reduces the number of different alleles in a population because they are closely related). Also it could cause health problems as they are a gene pool. If a new disease appears there's not much variation in the population.
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What is Genetic Engineering?
Its the process of moving Genes (sections of DNA) from one organism to another so that it produce useful biological products.
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What are some advantages of Genetic Engineering?
Its useful for producing organisms with new and useful features quickly.
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What are some disadvantages of Genetic Engineering?
There are many risks like harmful effects and also people worry about the DNA 'escaping'.
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How does Genetic Engineering work?
Firstly you take the desirable characteristic and then cut it from the DNA using enzymes and isolated. Then the useful gene is inserted into the DNA of another organism, which is then replicated.
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Give some Examples of Genetic Engineering.
In some places rice is heavily replied on so there is lack of Vitamin A as rice doesn't contain it. Genetic Engineering allows Vitamin A to be extracted and put in to rice and resolving the deficiency.
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How does Genetic Engineering help plants?
Some plants contain resistances like herbicides, frost damage and disease but the plants aren't that diserable so we extract those useful products and put it into common and useful plants.
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What are the moral and ethical issues involved with Genetic Engineering?
Some people think its wrong as animal could suffer as a result. Also people think that the poor will become 'Genetic Underclass' as the rich are choosing their childrens characteristics. Lastly it could have unknown impacts on the future.
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What is Gene Therapy?
Invovles altering peoples gene's in an attempt to cure genetic disorders.
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How many types of Gene Therapies are there?
Two, One invovles body cells and the second involves gametes, which is controversial.
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Explain the Gene Therapy about body cells.
It involves targeting the the most affected part of the body and altering the Gene. This doesn't affect the Gametes.
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Explain the Gene Therapy about Gametes.
This means that every cell of any offspring produced from these gametes will be affected by the gene therapy - and the offspring won't suffer from the disease. However it's illegal.
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What is Cloning?
Cloning is making an exact copy of another organism.
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What is the method of cloning known as the nuclear transfer?
This involves placing the nucleus of a body cell into an egg cell.
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What are some advantages of Cloning?
Cloning allows you to mass produce animals with desirabl characteristics.Also human embryos could be produced by cloning adult body cells.
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What are the risks of Cloning?
There is a lot of evidence that cloned animals might not be as healthy as normal ones and often live a lot less. In addition cloning could create consequences that we are unaware of.
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What are some ethical issues of Human Cloning?
There will be high rates of stillbirth and miscarriages. Since animal clones die early, maybe human clones will too. And lastly it could lead to psychological damage.
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Why is cloning plants easier than cloning animals?
Because many plant cells keep their ability to differentiate.
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What is Commerical Cloning?
Chosing the plant with the characteristics and then removing small pieces of tissue from the parent plant.You grow the tissue in a growth medium containing nutrients and growth hormones. As they produce shoots and roots the plant can be put in pots.
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What are pros and cons of Cloning Plants?
Pros: You will get a genetically identical plant. Con: Mass-produce plants are hard to grow from seeds.
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Card 3


What features does a bacteria cell have?


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Card 4


What does a Nucleus contain?


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Card 5


What is a Cytoplasm in terms of cells?


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