Topic 1b - transport in cells ( 5. exchange substances )

Question 1

what is the job of the lungs

Answer 1

to transfer oxygen to the blood and remove co2 from the blood. they do this with alveoli

Question 2

how do alveoli work

Answer 2

alveoli a tiny air sacs where gas exchange takes place. surrounded by a network of blood vessels known as capillaries. higher concentration of oxygen in the air than the blood, so oxygen diffuses out of the air and into the blood. There is a high concentration of carbon dioxide in the blood and a low concentration in the alveoli, so carbon dioxide diffuses from the blood into the alveoli.

Question 3

what are the adaptations of the alveoli

Answer 3

large surface area
thin walls
good blood supply

Question 4

what is the function of the small intestine

Answer 4

nutrients is absorbed into the bloodstream via the small intestine. to aid this absorption the small intestine is covered by several villi.

Question 5

adaptations of villi

Answer 5

single layer of surface cells
big surface area
good blood supply

Question 6

why do plants need gas exchange

Answer 6

they need co2 for photosynthesis. co2 diffuses into the air spaces within the leaf, then it diffuses into the cells where photosynthesis happens,

Question 7

how does the plant go through gas exchange

Answer 7

underneath the leaf is the exchange surface which is covered in holes called the stomata which co2 diffuses through.

Question 8

adaptations of the leaf

Answer 8

flattened shape increases the surface area.

Question 9

why do fishes need gas exchange

Answer 9

so they are able to breath.

Question 10

what is the gas exchange surface in fish

Answer 10

gills

Question 11

what is the structure of the gills

Answer 11

water(containing oxygen) passes through the mouth and passes out through the gills. as this happens oxygen diffuses from the water into the blood in the gills and co2 diffuses from the blood to the water.

Question 12

adaptations of gills

Answer 12

have thin plates called gill filaments which give lave surface area.
lamella have lots of capillaries
Covered in structures called lamella which give more surface area.
thin surface layer of cells

Question 13

how does the direction of the blood flow in the lamellae increase the efficiency of gas exchange in the gills.

Answer 13

maintains the concentration gradient between the water and the blood because it flows in the opposite direction to water.