transport systems in multi-cellular organisms

Question 1

Why do multicellular organisms need transport systems

Answer 1

Because they have many cells that are far from the external environment, simple diffusion is too slow and inefficient to transport nutrients, gases, and waste. A transport system ensures all cells receive what they need quickly and efficiently

Question 2

What are the limitations of simple diffusion in multicellular organisms

Answer 2

Too slow over long distances

Inefficient for delivering substances to deep tissues

Cannot meet the high metabolic demands of many cells

Question 3

How do single-celled organisms like amoeba transport substances

Answer 3

Amoeba use simple diffusion across their cell membrane because all parts of the cell are close to the external environment

Question 4

Why is diffusion enough for single-celled organisms but not for multicellular ones

Answer 4

Single-celled organisms have a large surface area to volume ratio, so substances can diffuse quickly. Multicellular organisms have a small surface area to volume ratio, making diffusion too slow to support life.

Question 5

What is the surface area to volume ratio

Answer 5

It’s the amount of surface area compared to the volume of a cell or organism. As size increases, volume grows faster than surface area, decreasing the SA:V ratio.

Question 6

Why is surface area to volume ratio important for diffusion

Answer 6

A higher SA:V ratio means more surface area for substances to diffuse through, which makes diffusion faster and more efficient.