organisation in plants and animals

Question 1

specialised cells

Answer 1

cells that carry out a specific task for the organism

Question 2

tissues

Answer 2

made up of multiple cells

Question 3

organs

Answer 3

made up of multiple layers of tissue

Question 4

organ system

Answer 4

made up of multiple organs designed to carry out a task

Question 5

organisms

Answer 5

made up of multiple organ systems to allow the function, survival and reproduction of an organism

Question 6

what is surface area to volume ratio

Answer 6

a measure of the amount of surface area per unit volume of an object or organism

Question 7

why is surface area to volume ratio important for living organisms

Answer 7

allows organisms to collect nutrients more effectively with ideal surface area : volume ratios

Question 8

what happens to the surface area to volume ratio of a multicellular organism as it increases in size

Answer 8

a smaller proportion of the organism is exposed to the external environment so the ratio decreases

Question 9

why do multicellular organisms need organ systems to function

Answer 9

they allow us to efficiently take nutrients from the environment and excrete waste into the surroundings

Question 10

how are exchange surfaces adapted to enable the efficient exchange of substances

Answer 10

• large surface area to maximise nutrient collection
• short diffusion distance by having thin surfaces
• a way to maintain the concentration gradient by having blood capillaries that carry blood away from the exchange site or by providing ventilation

Question 11

compare the structure of the gas exchange system with the root hair cells of a plant

Answer 11

• has lots of alveoli with lots of surface area for gas exchange
• elongated structure which increases surface area to collect water and minerals
• one cell thick alveoli and capillary

Question 12

alveoli

Answer 12

where gas exchange occurs