B2 - Cells, tissues and organs

Question 1

What are the functions of the:

• nucleus
• cytoplasm
• cell membrane
• mitochondria
• ribosomes

Answer 1

Nucleus - Controls the cells activities
Cytoplasm - Where chemical reactions take place
Cell membrane - Controls the movement of materials in/out
Mitochondria - Energy is released for respiration
Ribosomes - Protein synthesis takes place

Question 2

What are the functions of the:

• cell wall
• chloroplasts
• vacuole

Answer 2

Cell wall - Cellulose structure for support
Chloroplasts - Contain chlorophyll for photosynthesis
Vacuole - Contains cell sap

Question 3

Describe a bacterial cell

Answer 3

Has no nucleus (genetic material in the cytoplasm)
Very small
Have a cell membrane, wall and cytoplasm

Question 4

Describe a yeast cell

Answer 4

Single cell organism

Have a nucleus, cell wall, membrane and cytoplasm

Question 5

Name 4 examples of specialised cells

Answer 5

If a cell has many mitochondria it must need a lot of energy (muscle cell)

Cells with tails are able to move (sperm)

Receptor cells can detect stimuli

Root hair cells increase S.A to improve the efficiency of absorbing water

Question 6

What’s diffusion

Answer 6

The spreading out of particles from a high concentration to a low concentration, usually through a partially permeable membrane

Question 7

True or false, diffusion occurs in solids, liquids and gases

Answer 7

False, it only occurs in liquids and gases

Question 8

What’s the difference in concentration called?

Answer 8

Concentration gradient

The steeper the gradient the bigger difference in concentration

Question 9

Finish ; the larger the difference in concentration…

Answer 9

The faster the rate of diffusion

Question 10

Give 2 examples of everyday diffusion

Answer 10

The diffusion of oxygen to the cells from the bloodstream

The diffusion of carbon dioxide into actively photosynthesising plant cells

Question 11

What are tissues (not the paper kind)

Answer 11

A group of cells with a similar structure

Question 12

Give examples of animal tissue

Answer 12

Muscle - contract and relax to bring about movement
Glandular - produce enzymes or hormones
Epithelial - Covers parts of the body

Question 13

Give examples of plant tissue

Answer 13

Epidermal - Covers the plant
Mesophyll - Can photosynthesis
Xylem and phloem - Transport substances round the plant

Question 14

What’s an organ

Answer 14

Group of tissues with similar structures

Question 15

Give examples of animal organs

Answer 15

Stomach - made of muscular tissue to churn food
made of glandular tissue to produce digestive juices and enzymes
made of epithelial tissue to line inside and out

Question 16

What’s an organ system

Answer 16

Many organs working together, such as the digestive system. It changes insoluble molecules into soluble ones which can be absorbed by the blood. The stomach, pancreas, intestines and liver all are included.

Question 17

What are examples of organs in a plant

Answer 17

The leaf, stem and root

All made from different groups of tissues such as mesophyll

Question 18

What is meant by the term differentiation of cells

Answer 18

When a group of cells divide they form into group of cells with different jobs that form a group of tissues