Cells

Q - what is the function of the nucleus ?

A - controls acivities of the cell.

Q - which structure controls the movement into and out of the cell?

A - the cell membrane.

Q - where do most chemical reactions take place in a cell?

A - The cytoplasm

Q - what is the function of ribosomes ?

A - to produce protiens

Q - which structures are necassary for aerobic resperation to take place ?

A - Mitochondria

Q - which structures are nessasry for photosynthesis to take place?

A - chloroplasts

Q - why are some plant and animal cells specialised?

A - There are many different functions that plants and animals need to carry out.

Q - How can diffusion be defined ?

A - The random movement of particles from a high concentration to a low one.

Q - what substances might diffuse into or out of cells?

A - Oxygen, carbon dioxide, glucose.

Q - How is osmosis different to diffusion?

A - takes place through the a partially permable membrane and only involves the movement of water

Q - Name three structures common in both plant and animal cells?

A - Cell membrane, nucleus, cytoplasm.

Q - Where does aerobic resperation take place?

A - Mitochondria

Q - Name to materials that move across the cell membrane

A - Carbon dioxide and oxygen.

Q - Give to examples of specialised animal cells?

A - Egg cells and mucsel cells.

Q - How is the structure of a nerve cell related to it's function.

A - It is long and has many nerve endings to communicate with.

Q - What do we call the process that results in some cells becomeing specialised?

A - differentiation

Q - Why do particles move randomly?

A - They naturally vibrate as they have energy.

Q - Give an example of diffusion in living cells ?

A - Glucose into a respiring cell?

Q - Why is diffusion important ?

A - Cells need a constant supply of materials,and to get rid of waste materials.

Q - How is osmosis like diffusion?

A - I involves the random movement of particles.

Q - What does partially permeable mean?

A - A membrane that only allows small molecules through

Q - why do cells need water?

A - For support and chemical reactions take place in water.

Q - What is the function of ribosomes?

A - To synthesise (make protiens)

Q - Suggest how a sperm cell is adapted to it's function?

A - It is streamlined for swimming and has lots of mitochondria to produce energy

Q - why does diffusion require no energy form the cell?

A - Particals naturaly vibrate.

Q - Why would it be wrong to say that in osmosis water only passes from the weaker solution to the stronger solution.

A - It also passes from the stronger to the weaker because the movement of particals is random

Q - What substance, necessary for photosynthesis, do chloroplasts contain?

A - Chlorophyll

Q - What is the functio of the cell wall in plants?

A - For support

Q - Why does oxygen in the blood diffuse into respiring cells?

A - It is a higher concentration in the blood than in the cells.