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B1: Quiz 13 – Answers
B1: Quiz 13 – Answers
1) The three characteristics are:
2)
a) Diffusion – the net movement of particles from an area of higher concentration to an area of lower concentration (or the net movement of particles down a concentration gradient [high to low])
b)
i) Oxygen
ii) Carbon dioxide
c) Any 3 ways from:
3)
a) Any diagram like what is shown below. It can just be the outline of the villi and you do not need to show the capillaries.
- A Large surface area so that lots of diffusion can take place at the same time
- A thin membrane/ short distance, which provides a short diffusion pathway, thus increasing the rate of diffusion
- Efficient blood supply with lots of blood vessels so substances can move into and out of the bloodstream very quickly
2)
a) Diffusion – the net movement of particles from an area of higher concentration to an area of lower concentration (or the net movement of particles down a concentration gradient [high to low])
b)
i) Oxygen
ii) Carbon dioxide
c) Any 3 ways from:
- An extremely high surface area – each of the alveoli have a shape that has a very high surface area. Also, there are millions of alveoli in each of our lungs. The very high surface area allows for very fast diffusion as lots of gases can diffuse at once.
- A short distance between the alveoli and the capillary (bloodstream) – the distance is usually only 2 cells (one cell for the outside of the alveoli and the other for the capillaries). This short distance increases the rate of diffusion.
- A good blood supply – a network of capillaries goes very close to all of the alveoli which means that there is plenty of surfaces for the gases to exchange across. Also, the blood moves through the capillaries quickly, which ensures that the concentrations of the gases between the alveoli and the capillaries are different
- The alveoli have a moist lining – this moist lining dissolves gases, which increases the rate of gas exchange/ diffusion in the alveoli
3)
a) Any diagram like what is shown below. It can just be the outline of the villi and you do not need to show the capillaries.
b) The 3 are:
i) Mitochondria are where the majority of respiration reactions take place in cells. Respiration reactions provide cells with energy
ii) The villi contain lots of mitochondria to produce the energy required for active transport; active transport is the net movement of particles against a concentration gradient (low to high). By engaging in active transport, the villi can continue to absorb the soluble products of digestion into the bloodstream even when there is a low concentration in the gut and a higher concentration in the bloodstream
- A very high surface area from both all of the millions of villi in the small intestine and the microvilli on each of the villi
- A good blood supply through a network of capillaries that go very close to all of the villi
- A short distance for the soluble products of digestion to move (there is only a few cells between the small intestine and the bloodstream)
i) Mitochondria are where the majority of respiration reactions take place in cells. Respiration reactions provide cells with energy
ii) The villi contain lots of mitochondria to produce the energy required for active transport; active transport is the net movement of particles against a concentration gradient (low to high). By engaging in active transport, the villi can continue to absorb the soluble products of digestion into the bloodstream even when there is a low concentration in the gut and a higher concentration in the bloodstream
Questions
1) What are the 3 main characteristics that help to facilitate the efficient exchange of substances in animals/ humans? Explain why each of these characteristics are useful for exchanging substances.
2) The alveoli are where gas exchange takes place. The diagram below shows an alveolus with a capillary next to it.
1) What are the 3 main characteristics that help to facilitate the efficient exchange of substances in animals/ humans? Explain why each of these characteristics are useful for exchanging substances.
2) The alveoli are where gas exchange takes place. The diagram below shows an alveolus with a capillary next to it.
a) Gases move between the alveoli and the bloodstream. What is the name for the process for how the gases move? Give a definition for this process as well.
b)
i) What gas moves from the alveoli into the bloodstream?
ii) What gas moves from the bloodstream into the alveoli?
c) Give 3 ways that the alveoli are adapted for the efficient exchange of gases. Explain how each of the adaptations helps the efficient exchange of gases.
3) Villi are responsible for the absorption of the soluble products of digestion into the bloodstream from the small intestine.
a) Quickly draw a few villi. Do not worry too much about your drawing.
b) Give 3 ways that the villi are adapted for the efficient absorption of the soluble products of digestion. You do not need to explain how the adaptations are useful for the efficient absorption of the soluble products of digestion.
c) The cells in the villi contain lots of mitochondria.
i) What is the role of mitochondria in cells?
ii) Why do cells in the villi contain lots of mitochondria?
b)
i) What gas moves from the alveoli into the bloodstream?
ii) What gas moves from the bloodstream into the alveoli?
c) Give 3 ways that the alveoli are adapted for the efficient exchange of gases. Explain how each of the adaptations helps the efficient exchange of gases.
3) Villi are responsible for the absorption of the soluble products of digestion into the bloodstream from the small intestine.
a) Quickly draw a few villi. Do not worry too much about your drawing.
b) Give 3 ways that the villi are adapted for the efficient absorption of the soluble products of digestion. You do not need to explain how the adaptations are useful for the efficient absorption of the soluble products of digestion.
c) The cells in the villi contain lots of mitochondria.
i) What is the role of mitochondria in cells?
ii) Why do cells in the villi contain lots of mitochondria?