Transport Systems & Gaseous Exchange

Question 1

Roles of Respiratory, circulatory and excretory system

Answer 1

Respiratory:

• exchange of gases with environment
• respiration (take in oxygen, breathe out carbon dioxide)

Circulatory:
- transportation of chemicals, waste products and dissolved gases around the body

Excretory:

• regulating body fluids & salt levels ‘osmoregulation’
• filters waste

Question 2

List 4 different ways of gas exchange surfaces:

Answer 2

Gills, lungs, skin and trachea

Question 3

Provide examples of animals using these gas exchange levels and outline its use

Answer 3

Gills: fish

• large surface area, fractal
• collects oxygen through fishes mouth

Lungs: human

• inside body for protection
• alveoli, highly folded
• collects oxygen through diffusion

Skin: Frog

• uses both skin and lungs
• oxygen diffuses through skin
• very ridgy skin surface

Trachea: Grass hopper

• uses breathing organs, branching air tubes
• air directly to cells through the fine branches

Question 4

what are the similarities between all these different gas exchange surfaces?

Answer 4

needs moist surface & all maximise surface area without volume

Question 5

2 types of circulatory systems, examples:

Answer 5

open: bugs
- body cavity bathes in colourless fluid
- not carried by blood
- tubular hearts

closed: fish, mammals
- closed in tubes, continuous system
- have capillaries
- thin walls for gas exchange

Question 6

what are the requirements of cells, and why do we need transport systems in multicellular organisms?

Answer 6

• small single-celled organisms like amoebas have a large SA, can obtain nutrients easily & get rid of waste easy too
• large multicellular organisms have a small SA:V ratio
• inefficient for requirements of organism
• needs transport system

Question 7

What is translocation and transpiration?

Answer 7

Transpiration:

• movement of water from roots to the leaves
• only goes up
• through xylem
• PASSIVE transport (osmosis & cohesion: water molecules stick to each other and pull up)

Translocation:

• movement of nutrients though phloem
• can go up or down
• ACTIVE transport

Question 8

How do root hairs transport stuff?

Answer 8

though diffusion, goes into xylem

Question 9

How do stomates transport stuff?

Answer 9

though diffusion again, out of plant