All biology Flashcards
Nucleus function
Controls cell activity
Makes proteins
Contains chromosomes- DNA which carries the genes
Cell membrane function
Boundary between cytoplasm and surroundings
Controls what goes in and out the cell
Selectively permeable
Cytoplasm function
Jelly-like liquid where chemical reactions occurr
Mitochondria function
Aerobic respiration
Produces atp
Ribosomes function
Make proteins from amino acids
Chloroplasts
Absorb light energy use it to carry out photosynthesis and make biological molecules for plant cells
Cell wall
Made of cellulose
Keeps plant in fixed shape
Vacuole
Filled with sap
Stores dissolved sugars minerals ions and other substances
Calculating magnification
Objective magnification = size of image / size of object
three parts of the plant cell that would not be found in an animal cell
vacuole and chloroplasts and cell wall
How is the plant cell different from the bacterial cell?
chloroplasts in a plant cell
what are pathogens?
microorganisms that can cause disease
What is nutrition?
Makes glucose, which can be used to make other biological molecules, by photosynthesis or eat and digest other organisms to absorb biological molecules
What is Respiration?
Chemical reaction, transferring energy from glucose to form ATP
What is growth?
Increase in size and mass due to increase in cell number
What is reproduction?
Production of new organisms (offspring)
What is homeostatis?
Control of internal conditions, such as water potential and temperature
What is movement?
Change of position or shape of organs (e.g. leaf moving towards light) or organism
What is excretion?
Removal of waste products from chemical reactions (e.g. carbon dioxide)
What is sensitivity?
Detect and respond to changes in the organism’s surroundings
ingestion process
food entering the mouth
digestion process
break down large molecules to small molecules
absorption process
Small food molecules move from the small intestine into the blood
assimilation synthesis process
Small food molecules are used to build large molecules
egestion
removal of undigested food from the anus (faeces)
describe the process of digestion in the mouth
Mechanical digestion breaks down the food in the mouth into smaller pieces. Then amylase in your saliva breaks starch down into shorter chains of glucose molecules
In what way is the structure of the artery different from the vein
artery has no valves, narrower lumen, thicker wall, more muscle, more elastic
artery function
takes oxygenated blood from the heart to the body
vein function
takes deoxygenated blood from the body to the heart
Blood vessels in the Pulmonary circulation
pulmonary vein and artery
Blood vessels in the Systemic circulation
vena cava, hepatic portal vein, renal artery and vein, aorta, hepatic artery and vein-mesenteric artery
Why do larger organisms have to have a circulatory system?
To deliver food and oxygen to cells and remove carbon dioxide and waste, effective diffusion
Arteries three specialisations for their functions
- Large in diameter, muscular with thick walls- important to contract and keep blood flowing at high pressure
- elastic walls important because they stretch and recoil to keep blood moving under high pressure without bursting
- Smooth lining (endothelium) important for stopping blood clots forming
Veins four specialisations for their functions
- large in diameter, important for plenty of space for blood to move, reducing loss of pressure
- Thin muscle layer in wall important to contract to maintain pressure and keep blood moving
- Smooth lining (endothelium) important to stop blood clots
- Pocket valves important to ensure blood only flows in one direction, can push blood up the body
Capillaries two specialisations for their functions
- Narrow important to slow down blood flow, so that exchange of substances with cells can happen
- wall is one cell thick important for fast diffusion distance
Describe the cardiac cycle (8 points)
- Blood flows from veins into atria
- Atria contract
- Blood flows into ventricles
- Ventricles contract
- Tricuspid and bicuspid valves close
- Blood flows into arteries & away from the heart
- Ventricles relax
- Semi-lunar valves close
Why is the left ventricle thicker than the right ventricle?
the left has higher pressure to withstand as it has to pump blood around the body
Plasma description and function
straw like liquid, mainly water- transports blood cells
Phagocytes description and function
a type of white blood cell that ingests and destroys pathogens such as bacteria
Lymphocytes description and function
cells with a very large nucleus that make antibodies
Platelets description and function
Platelets description and function
Red blood cells description and function
small red cells that transport oxygen
What proteins do red blood cells contain?
haemoglobin
How is oxygen carried by red blood cells?
oxyhaemoglobin
Red blood cells have no nucleus, but how does this help them?
More space for haemoglobin and oxygen to be transported
Red blood cells have a biconcave shape, how does this adaptation help them?
Faster rate of diffusion due to the surface area to volume ratio
Order the levels of organisation in organisms from largest to smallest
organ system- largest organ tissue cell organelle
What is diffusion?
The random movement of particles from an area of high concentration to low concentration
What is Osmosis?
The net diffusion of free water molecules from an area of high water concentration to an area of low concentration across a partially permeable membrane
What is active transport
The movement of molecules from an area of low concentration to an area of high concentration using ATP
What 4 main factors affect the rate of diffusion and osmosis?
- TEMPERATURE- at higher temperatures molecules have more kinetic energy so they move faster and diffusion is faster
- CONCENTRATION GRADIENT- if there is a large difference in concentration between areas, then diffusion is fast
- DISTANCE- diffusion takes longer when the molecules have further to travel
- SURFACE AREA TO VOLUME RATIO- a larger surface area speeds up diffusion as there are more opportunities for the molecules to move
What is a stimuli?
Change in the animal’s surroundings (eg ball being thrown at you)
What is a receptor?
The organ which detects the change (eg your eye)
What is an effector in the example of a ball being thrown at you?
The muscles as they contract to catch the ball
What is the energy conversion of the eye as a receptor
Light –> electrical impulses
What is in the central nervous system?
Brain and spinal chords
What is in the peripheral nervous system?
Cranial nerves and spinal nerves
2 advantages of reflex actions
- The behaviour does not need to be learned so the damage can be avoided at an early age
- The response is fast and automatic meaning the damage done is reduced
What is the function of rods?
Sensitive to low light, detects shades of grey
Provides us with night vision when you can see shapes not colours
Found in the retina but not in the centre of the fovea or blind spot
What is the function of cones?
Sensitive only to high light intensity (doesn’t operate in poor light)
Detects colour
There are three types, sensitive to red, green and blue light
Concentrated in the fovea