B1 Cell Structure And Transport

Question 1

What is diffusion

Answer 1

The spreading of particles of a gas, or any substance in solution (a solute).

Question 2

What is active transport

Answer 2

Allows cells to move substances from an area of low concemtration to an area of high concentration. This movement is against a concentration gradient.

Question 3

What does active mean

Answer 3

Energy requiring

Question 4

What is a concentration gradient

Answer 4

A concentration gradient happens when the concentration of particles is higher in one area than another

Question 5

What three factors can affect the rate of diffusion

Answer 5

Temperature - speeds it up
Increased concentration gradient - makes it faster (more particles to spread)
Distance - the lower the distance the faster it will happen

Question 6

Solute

Answer 6

A substance in solution

Question 7

Gas exchange

Answer 7

The diffusion of oxygen and carbon dioxide in opposite directions in the lungs

Question 8

Osmosis

Answer 8

A special type of diffusion, only involves the movement of water

Question 9

What is an isotonic solution

Answer 9

The concentration gradient outside the cell is the same inside the cell

Question 10

Hypertonic solution

Answer 10

The concentration outside the cell is higher than the internal concentration

Question 11

Hypotonic solution

Answer 11

The concentration is lower outside the cell than the internal concentration

Question 12

Turgid

Answer 12

The plant cell is hard and firm

Question 13

Flaccid

Answer 13

When a plant cell is lacking turgidity so it’s not reciving enough water

Question 14

Plasmolysis

Answer 14

Is the shrinking of cytoplasym away from the wall of a living cell due to water loss

Question 15

What does the nucleus do ?

Answer 15

Contains genetic material, including DNA, which controls the cell’s activities

Question 16

Cytoplasm function

Answer 16

A jelly-like material that contains dissolved nutrients and salts and structures called organelles. It is where many of the chemical reactions happen.

Question 17

Cell membrane function

Answer 17

controls the movement of substances in and out of the cell.
Its structure is permeable to some substances but not to others.

Question 18

Mitochondria function

Answer 18

Organelles that contain the enzymes for respiration, and where most energy is released in respiration.

Question 19

Ribosomes function

Answer 19

Tiny structures where protein synthesis occurs.

Question 20

Chloroplast function

Answer 20

Organelles that contains the green pigment, chlorophyll,
which absorbs light energy for photosynthesis.
Contains the enzymes needed for photosynthesis.

Question 21

Cell wall function

Answer 21

Made from cellulose fibres and strengthens the cell and supports the plant.

Question 22

Permenent vacuole function

Answer 22

Filled the cell sap to help keep the cell turgid

Question 23

Prokaryotic cells

Answer 23

Cells of bacteria, a simple cell without a nucleus, the DNA is free in the cytoplasym

Question 24

Eukaryotic cells

Answer 24

Cells of animals,plants and fungi
A type of cell that has a nucleus

Question 25

Describe osmosis

Answer 25

Osmosis is the movement of water molecules through a partially permeable membrane (e.g. cell membrane) from a dilute solution to a concentrated solution

Question 26

Describe a sperm cell's structure

Answer 26

1. A long tail whips side to side for movment 2. The middle section is full of mitochondria for the energy used by the tail 3. Acrosome (pointy head) stores digestive enzymes for breaking down the outer layers of the egg 4. A large nucleus contains genetic information

Question 27

Describe a nerve cells structure

Answer 27

Dendrites - make connections to other nerve cells Axon - carries nerve impulse from one place to another Synapses/nerve endings - pass the impulses to another cell or between a nerve cell and a muscle using special transmitter chemicals

Question 28

Describe a root hair cells structure

Answer 28

1. They increase the surface area avaliable for water to move into the cell 2. They have a large permenant vacuole that speeds up the movement of water by osmosis 3. They have lots of mitochondria needed for active transport of mineral ions into the root hair cell

Question 29

How does the xylem cell function

Answer 29

Transports water and mineral salts from the roots up to other parts of the plant Transpiration stream (evaporation and movement of water away from the plant)

Question 30

What is the function of phloem

Answer 30

Transports surcrose and amino acids from the leaves and other parts of the plant Process of translocation (the transport of dissolved sugars around a plant in the phloem)