That base 'A' always goes with base 'T' and that bases C and G go together as well
What Forms a code for controlling the production of proteins?
What as base pairs held together by?
How do we use DNA to make protein?
1) part of the DNA molecule unwinds
2) a length of mRNA is made by using the unwound section of DNA as a template
3) mRNA passes out of the nucleus
4) the length of mRNA goes to a ribosome
5) transfer RNA molecules bring amino acids to the ribosome
6) The amino acid are joined together in a specific sequence that is determined by the sequence of bases on the length or RNA
7) the protein folds into the correct shape
Give an example of structural protein
Give aN example of a protein hormone
Get an example of a carrier protein
Give an example of a receiver protein
Enzymes are catalysts, true or false
What is. Mutation?
A random change in a gene
What could increase the chances of your genes mutating
Chemicals (such as tar in tobacco)
Ionising radiation (Such as x-rays or UV lights)
What can mutations cause?
Enzymes not to work
Differently shaped haemoglobin
What does respiration provide?
Where does respiration take place?
In almost every cell where energy is released from a glucose molecule
How do we get glucose?
By digesting carbohydrates we have eaten
What does respiration involve?
Many chemical reactions, all controlled by particular enzymes
Why might some birds and mammals hunt at night when it is cold?
Their prey release heat energy which they can detect
What is aerobic respiration?
Respiration that uses oxygen. It happens continuously in the cells of plants and animals
What is anaerobic respiration?
Respiration that does not use oxygen and does not happen continuously in the cells of plants and animals
How do some animals get through the cold winters?
They hibernate. (Hedgehogs, squirrels)
They store food in the run up to the cold season
Their fur/feathers grow more
They migrate to warmer places
What is the respiration equation?
Glucose+oxygen--> carbon dioxide +water
What is the equation for aerobic respiration?
Where does aerobic respiration take place?
In the mitochondria in every cell
Explain the aerobic respiration process
Glucose and oxygen are carried to the cells in the blood and diffuse through the cell membrane, into the body of the cell
What does the speed that oxygen is used up indicate?
How quickly aerobic respiration is going on (the metabolic rate)
When would your body use anaerobic respiration as well as aerobic respiration?
When you start to do hard exercise and your heart rate cannot go up quickly enough to supply the oxygen to your muscles.
Where does a anaerobic respiration take place?
In the cytoplasm in cells
What happens to lactic acid during anaerobic respiration?
It diffuses through the cell membrane, into the blood, to be carried away to the liver
How would you figure out the RQ? (Respiratory quotient)
Volume of carbon dioxide produced
Volume of oxygen consumed
What is the RQ? (Respiratory quotient)
The ratio of carbon dioxide produced during respiration in a given time, with the amount of oxygen consumed
What factors could influence the rate at which respiration takes place?
Blood oxygen level
pH of your blood
Whether you have taken drugs (slows down respiration rate)
Whether you have drunken alcohol (slows down respiration rate)
The amount of excrescences you have done
Wether you are awake or asleep
What happens if your respiratory rate slows down too much?
You risk respiratory arrest
What is muscle fatigue?
The term used to describe the feeling of doing a lot of exercise, to the point of where you feel you cannot do any more.
It occurs when muscles are used with more effort than usual to achieve a desired level of force. The body temporarily exhausts its supply of energy.
Is mitosis sexual reproduction?
No mitosis is asexual reproduction
Is meiosis sexual or asexual reproduction?
Are cells produced my mitosis genetically identical or not?
Yes cells produced by mitosis are identical.
Go through the stages of mitosis.
1) Each chromosome has made a copy of itself
2) poles are formed each and of the cell
3) The duplicated chromosomes line up across the centre of cell
4) The double chromosome splits into it's identical copy. Each copy Moves to opposite ends of the cell
5) two new nuclei form, each with a full set of chromosomes. The cell divides into two genetically identical cells
What is a diploid?
A cell that that has a nucleus with two sets of chromosomes, a body cell
Why is mitosis used for asexual reproduction?
They have the same alleles as the parent and it means organisms can be larger
What is mitosis used for in mature animals?
Repair tissue cells
What organ systems do multicellular organisms have?
A nervous and endocrine system (Allowing communication between cells)
A circulatory system (supplying cells with nutrients)
Respiratory system and digestive system (Controlling exchanges with the environment)
What are gametes?
What is the definition of meiosis
Cell division that occurs to form sex cells, resulting In for genetically different cells
What is a haploid
Cells that have a nucleus with one set of chromosomes
What is a zygote?
A diploid cell resulting from the fusion of an egg and a sperm
What is fertilisation?
The joining of male and female gametes to create a new individual
What is the function of red blood cells?
To carry oxygen from your lungs to respire cells in your tissues
What shape is a red blood cell?
Why does the shape of a red blood cell benefit you?
Because they are biconcave, their surface area is a lot larger than their volume and that means more oxygen can be transported
Do red blood cells have a nucleus?
No, meaning they contain no genetic information.
What is the function of a white blood cell?
To defend you against viruses, bacteria, diseases and micro-organisms
Do white blood cells have a. Nucleus?
Yes a large one.
What are platelets?
Small cells that help your blood to clot when you cut yourself
What do platelets prevent?
You from bleeding and from bacteria entering the wound
Do platelets have a nucleus?
What is plasma?
Straw coloured liquid part of blood.
How much of plasma is water?
What does plasma in your blood carry?
Digested food (such as glucose)
Why are arteries so well adapted?
They have a thick muscular eleastoc wall that allows them to withstand the high pressure generates by your heart.
What do arteries do?
Carry oxygenated blood away from the heart
Why are veins so well adapted?
They have a thinner wall and larger lumen. The blood is under low pressure. To prevent blood flowing backwards, veins have valves.
What is the lumen?
Te space inside a vein
Why are capillaries so well adapted?
Capillary walls are permeable
Where are capillaries found?
In tissues and organs
What happens in a capillary?
Blood flows slowly through capillaries and exchanges materials with the tissues.
What does permeable mean?
Allows liquids and gases to pass through
What does double circulation mean?
The heart pumps blood twice through the heart
Where do the left and the right atria receive blood from?
What do the left and the right ventricles do?
Pump blood into arteries
What do valves prevent?
The backwards flow of blood
Where does the right side of the heart pump blood to?
How does the right ventricle ensure that it does not damage the lungs?
It has thinner walls and generates less PRESSURE
Which side of the heart pumps blood to the majority of your body?
What features does the left venricle wall have?
Thick and muscular walls, meaning it can generate higher pressures, allowing fast delivery of oxygen to body tissues
(And quick removal of waste)
What happens at the same time as blood is pumped into the aorta?
Blood is pumped into the pulmonary arteries
Where is the tricuspid valve found?
The right is of the heart.
What is the function of the tricuspid valve?
To pump blood to the lungs
Where can you find the semilunar valves?
The left side of the heart
What is the function of the semi lunar valves?
To deliver oxygen to the body tissue
What do plant cells have that animal cells do not? (3 things)
What is the mitochondria?
Small rod shaped structures that release energy during aerobic respiration
What is a cell membrane?
A thin layer around the cell. It controls the movement of substances into and out of the cell
What is the nucleus?
A large structure inside the cell. It contains chromosomes made of DNA. The nucleus controls the activities of the cell and how it develops.
What is cytoplasm?
A jelly-like substance containing many chemicals. Most of the chemical reactions of the cell occur here.
What is the cell wall?
A layer outside the cell membrane. It is made of cellulose, which is strong and supports the cell
What is a permanent vacuole?
A fluid filled cavity. The liquid inside is called cell sap. The sap helps to support the cell.
What are the chloroplasts?
Small disk shaped structures found the cytoplasm of some plant cells. They contain the green pigment chlorophyll that traps light energy for photosynthesis. Chloroplasts of found in the cells of leaves and stems (where photosynthesis occurs) But not in the cells of roots or flowers
What is a stem cell?
An undifferentiated cell that can divide my mitosis and is capable of differentiating into any cell types found in that organism