B2.2.1 - Exchange And Transport Flashcards Preview

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Flashcards in B2.2.1 - Exchange And Transport Deck (16):
1

What is the surface area to volume ratio?

The surface area per unit volume of an object

2

Why is surface area to volume ratio important?

It can help with diffusion

3

If an organism is large, will the surface area volume ratio be higher or lower?

Lower

4

If an organism is small, will the surface area volume ratio be higher or lower?

Higher

5

Why can most multicellular organisms not use simple diffusion to survive?

It can not occur fast enough to meet the cells’ demands

6

What do lungs have to help with gas exchange?

Alveoli

7

Why are alveoli important to lungs?

It maximises the rate of diffusion into the bloodstream as it increases the surface area

8

What are exchange surfaces?

A process where an organism exchanges something in need of something else

9

What do intestines contain to help with diffusion?

Villi

10

What does villi do to help the intestines?

It increases the surface area of the intestines

11

Why is it good for the intestines to have a high surface area?

It increase the rate of diffusion of digested food molecules

12

What do you call the villi which are on the villi that are very small?

Microvilli

13

What tubes carry water and mineral ions around in a plant?

Xylem tubes

14

What tubes can transport sugars and amino acids in plants?

Phloem tubes

15

How are alveoli adapted for gas exchange?

Spherical shape gives relatively large surface area
Very thin walls mean shorter distance for diffusion
Ventilation moves air in and out and helps maintain a steep diffusion gradient
Good blood supply maintains concentration gradient for diffusion by removing oxygen and bringing lots of carbon dioxide

16

How have villi adapted to digestive diffusion?

Rich bloody supply produces steep concentration gradient
Large surface area
Thin wall so short distance for diffusion