Respiration

Question 1

What is aerobic cellular respiration?

Answer 1

organisms use oxygen to extract energy from food

Question 2

What is anaerobic respiration?

Answer 2

Orgs don’t use O2 to extract energy from food but instead use a different compound (nitrate/sulphur)

Question 3

What are the benefits of Aerobic respiration?

Answer 3

• Releases more ATP molecules than ana resp
• May have allowed for the evolution of multicellularity and larger org size

Question 4

What are the benefits of Ana resp?

Answer 4

• Quickly releases energy
  Can occur in low O2 environments.

Question 5

How did mitochondria evolve in the cell?

Answer 5

2 hypothesis:
1. Eukaryote host engulfed an aerobic prokaryote (traditional view)
2. Prokaryote host engulfed a facultative anaerobic prokaryote

Question 6

Explain the role of O2 and evolution

Answer 6

Look at Celeste’s Notes on Insect EX

Question 7

Explain bacteria and archaea resp:

Answer 7

Can respire aerobically, anaerobically, or both.

Question 8

What is obligate aerobic reps:

Answer 8

Cannot survive WITHOUT O2

Question 9

What is obligate anaerobic resp?

Answer 9

Cannot survive in the presence of O2.

Question 10

What is facultative anaerobic resp?

Answer 10

• Can grow without O2 but use O2 if its present.
• Anaerobic bacteria use other compounds such as hydrogen sulphide or methane instead of using O2

Question 11

Explain how resp occurs in Fungi:

Answer 11

• Most fungi are aerobic but some are anaerobic
• In soil Hyphae absorb O2 from tiny air spaces in between soil particles.
  -O2 and CO2 can move across the thin outer wall of hyphae by absorption

Question 12

Explain the process of fermentation:

Answer 12

Using bacteria or yeast to break down starch and sugar

Question 13

Explain the process of plant resp:

Answer 13

1. All parts of a plant need to respire
2. Plants obtain oxygen via diffusion through:
   a. Stomata (leaves and stems)
   b. lenticels (stems and woody plants and some roots).

Question 14

Explain how light affects plant resp:

Answer 14

• When dark (minimal light): only resp occurring, O2 taken in , CO 2 released.
• When light: respiration < photo, O2 released, CO2 taken in.

Question 15

Describe the different type of plant roots and why this is important:

Answer 15

1. Aerial roots: pneumatophores are useful in environments with anoxic or water legged soil.
2. Aerenchyma: small air pockets in plant tissue. Allows for exchnage of gases from exposed parts of the plant to submerged parts. (Aeranchyma = bigger in stagnant water).

Question 16

Why are plant leaves important?

Answer 16

• Leaves/some stems have STOMATA which are tiny openings allowing for gas exchnage
• Stomata present in the sporophyte generation of all land plants (except __).
• Stomata can open and close depending on plant condition and environment.

Question 17

What are the different types of gas exchange systems?

Answer 17

1. Direct diffusion
2. Integumentary exchange
3. Trachea
4. Gills
5. Lungs

Question 18

What are the four stages of resp (not all animals use all four)?

Answer 18

1. Breathing
2. Gas exchange
3. Circulation
4. Cellular respiration

Question 19

Explain what occurs during direct diffusion, and why only small animals can use this method:

Answer 19

1. Small animal obtain O2 through direct diffusion
2. DD of O2 across outter membrane can supply O2 to all cells
3. Larger animals - cannot use this method bc diffusion would not be able to provide O2 quickly enough.

Question 20

What is integumentary exchange?

Answer 20

1. Skin used as gas exchange surface
2. Gases then dissolve into circ system
3. must occur in a moist environement
   E.G. FROGS

Question 21

How does the trachea allow for GE?

Answer 21

1. Insects have a system of tubes (trachea) branching throughout their body to provide O2 to all cells
2. Openings of trachea = spiracles (open and close when needed)
3. some insects ventilate the tracheal system with muscle contractions
4. Separate to circulatory system

Question 22

Explain how Gills assist in GS/R:

Answer 22

1. Several in a cavity/externally
2. highly folded thin tissue filaments
3. water passes over the gills and O2 rapidly diffuses across the gills into the CS/Coelomic fluid
4. Counter current system

Question 23

Explain the role of lungs in Resp/GE in relation to different animals:

Answer 23

1. Amphibians: simple sac like lung
2. Reptile: vary tend be sac like but sometimes divided, use asthmaery pump to pump the lungs by using the body wall.
3. Mammals: have branching lungs that terminate in tiny air sac (alveoli)
4. Birds: Composed of a parallel series of tubes (parabronchi) - air sacs inflated and deflated in a complex sequence to push air through the lungs (takes two breath cycles to complete).

Question 24

Give an example of a miscellaneous respiratory system:

Answer 24

1. Sea cucumbers: specialised resp system/tree inside the anus (breathing through the butt)
2. Fitzroy river turtles: can obtain up to 70% of its O2 needs through its cloaca
3. Sloth - organs are attached to ribcage so it doesn’t press on diaphragm when hanging upside down
4. Diving bell spider - special hair on body to hold air bubbles as dive into water.