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biology
Question | Answer |
---|---|
Name all the subcellular cells of an animal and plant cell? | nucleus,cell membrane,cytoplasm,mitochondria,ribosomes,cell wall,permanent vacuole,chloroplast |
Describe the features of a bacteria cell? | cytoplasm,cell membrane,cell wall,plasmids |
What is the formula for magnification? | magnification = image size/real size |
What are the differences between a electron and light microscope | light microscopes are cheaper electron microscopes have a greater resolution and magnification. |
What is cell differentiation ? | is the process when a cell changes to become specialised for its job |
State examples of specialised cells and their features? | sperm cell: long tail,streamlined head,lots of mitochondria root hair cell:big surface area, xylem and phloem: xylem cells are hollow , phloem have very few sub cellular structures. |
What are chromosomes | chromosmes contain genetic information |
What is the cell cycle | the cell cycle makes new cells for growth,development and repair |
What are the stages of mitosis | 1) the cell duplicates 2)the chromosomes line up and they go to opposite ends 3)membranes form and these become the nuclei 4)cytoplasm and cell membrane divided 5) and two daughter cells are produces |
How do bacteria cells replicate | they use binary fission |
What is used to work out the time it takes for bacteria to replicate | the mean division time |
How to calculate the area of an inhibition zone | area = pie * radius squared |
What can an embryonic stem cell do | they can differentiate into any cell |
What can stem cells do | they can cure many diseases |
Why are people against the use of stem cells | embryos are a potential life |
How do plants use stem cells and where are they found | plant stem cells are called meri-stem cells and they can differentiate into any type of cell |
diffusion | the movement of particles from and area of high concentration to an area of low concentration |
osmosis | the movement of water particles from and area of high concentration to an area of low concentration through a partially permeable membrane |
What happens to the rate of diffusion if you increase the surface area | the rate of diffusion increases |
What is active transport | the movement of mineral ions from an area of low concentration to an area of high concentration against a concentration gradient |
Why do we need active transport in the gut | to stop us from starving and when there is a low concentration of nutrients in out gut but a high concentration in our blood |
How are root hair cells adapted to carry out active transport | they have a large surface area to absorb water |
Where does gas exchange happen | in the alveoli |
How are the alveoli adapted | they have an enormous surface area a moist lining very thin walls good blood supply |
What are villi and how are they adapted | the villi increase the surface area so that food is absorbed much more quickly into the blood they have a single layer of surface cells and a very good blood supply for quick absorption |