Diffusion and Cell Size

Question 1

Diffusion

Answer 1

the movement of substances from an area of high concentration to low concentration

Question 2

Key Idea

Answer 2

Diffusion is less efficient in cells with a small surface area relative to their volume than in cells with a large surface area relative to their volume

Question 3

How do larger organisms overcome the physical limit to growing?

Answer 3

By becoming multicellular

Question 4

Object Size

Answer 4

When an object is small, it has a large surface area in comparison to its volume. As an object gets larger, its surface area compared to its volume is smaller.

Question 5

Single celled organisms

Answer 5

As they are small, they have a large surface area relative to the volume, The requirements are met by diffusion or active transports of materials in and out of the cells.

Question 6

Multicellular organisms

Answer 6

As they are quite large, they have a small surface area compared to their volume. They need specialized systems to transport the materials they need to and from the cells and tissues in their body.

Question 7

Surface Area to Volume Ratio

Answer 7

A measure of the critical balance between the surface area available for substance exchange and the volume of the cell.

Question 8

Cells may increase their SA:V by

Answer 8

• Having a long thin shape/elongated shape
• Folding the surface of the object
• Having thin, flat cells
• Plant cells have a large vacuole that pushes organelles to the edge where they get regular access to resources.