Organisation Flashcards
When a cell is specialised what happens to it?
may change shape or develop a different sub-cellular structure to let it to carry out a specific function.
When it is specialised it will do it more efficient but may lose the ability to do other jobs
What does the long tail and nuclease do in a sperm cell/what is the main job of the sperm cell?
Its job is to join with the ovum
- long tail-allows it to swim, to the ovum
- nucleus-contains half the genetic material an adult cell would have
Name the three main things in a nerve cell and their function?
- axon-carries the electrical impulses from one part of the body to another
- myelin-axon is covered with myelin, myelin insulates the axon and speeds up the transmission of nerve impulses
- synapses-end of the axon, they are junctions which allow the impulse to pass from one nerve cell to the other.
What do muscles cells do?
they can contract (get shorter) and contain protein fibres which can change their length.
- mitochondria-provide energy for muscle contraction
- muscle cells work together to form muscle tissues
What does a root hair cell not contain that a plant cell does and why ?
does not contain chloroplast because they can’t carry out photosynthesis as they are underground
What are the tubes made from/What do end walls do in a xylem cell?
form long tubes
thick walls containing lignin + supports the plant but xylem cells can die
end walls between the cell have broken down, now there’s a long tube for water and minerals to flow easily
What is the purpose of phloem vessel cells and companion cells?
- phloem vessel cells-no nuclease, limited cytoplasm, end walls have have pores called sieve plates
- companion cell-mitochondria provides energy to the vessel cell
Describe the difference between tissues,organ and organ system?
TISSUES-group of cells which have similar function+ structure
ORGAN-group of tissues work together for specific function (EG stomach)
ORGAN SYSTEM-group of organs to form organisms (EG digestive system)
How does digestion begin?
1)First food is chewed. Enzymes in the saliva begin to digest the starch into glucose
2)Food passed down to oesophagus into the stomach.
In the stomach,(contains hydrochloric acid) the enzymes begin to digest the proteins
What does the pancreases digest?
5) Chemicals are released into the small intestine from the liver and pancreas
6) Pancreas release enzymes which continue the digestion of starch + protein. They also start the digestion of lipids
What is lock and key in terms of enzymes?
large protein molecules, have space between protein molecule called active sight (this is what the substrate attaches to)
substrate must fit into the active site (lock and key
theory)
What does protease break down in digestion?
breaks down protein to amino acid
produced in the stomach, pancreas and small intestine
What is bile?
Bile is made in the liver and stored in the gall bladder
speeds up the digestion of lipids but it is not an enzyme it just breaks up fat droplets to small droplets
which increases the surface area.
alkaline to neutralise the hydrochloric acid
How do you prepare the solution for the food test?
- Take the food sample and grind this with distilled water using a motor and pestle to make a paste.
- Transfer the paste to a beaker and add more distilled water.Stir so the chemicals in the food dissolve in the water
- Filter the solution to remove suspended food particles
What do red blood cells do?
- Transports oxygen from the lungs to the body cells
- haemoglobin + oxygen bind together in the lungs to form oxyhaemoglobin
- oxyhaemoglobin releases oxygen + haemoglobin in the organ
What are arteries?
- take blood from your heart to organ
- Thick walls made from muscles because of high pressure blood flow
- elastic fibres
Where does oxygenated and deoxygenated blood flow from and to?
deoxygenated blood from the heart -lung
oxygenated blood goes from the lungs - heart
heart pumps oxygenated blood to the organs were the blood transfers its oxygen to the body cell
the blood then goes back to the heart (double circulatory system)
What are the four chamber the heart?
four chamber :right and left atrium, right and left ventricle
How does gaseous exchange take pace?
Air passes into the lungs through a tube called trachea
this then subdivides into tubes called bronchi
The bronchi then divides to form bronchioles and the bronchioles have tiny sacs called alveoli (gases diffuse in and out the blood stream
What is the difference between a communicable and non communicable disease?
COMMUNICABLE -can be passed around from one person to another (EG. measles)
NON-COMMUNICABLE-Cant be passed around (EG coronary heart disease)
not caused by pathogens
What is cardiovascular disease?
When the diet is high in fat and low in veg increases certain type of cholesterol in the blood this increase the rate of fatty materials built up in the artery
What is coronary heart disease?
Coronary heart disease is layers of fatty material build up inside the coronary arteries
What is at the top and bottom of the plant?
EPIDERMIS-top and bottom of the leaf is covered with very thin layer of cells(epidermal cells)& protects the surface of the leaf Upper epidermis is transparent so it allows light to pass through for photosynthesis
Where is the main site for photosynthesis?
PALISADE MESOPHYLL- contains palisade cells which are packed with chloroplast(main site for photosynthesis)
