GCSE Biology - Active Transport #9

The video tutorial explains active transport, contrasting it with diffusion. Diffusion is a passive process where substances move down their concentration gradient, while active transport requires energy to move substances against the gradient. Active transport occurs across cell membranes and involves special proteins. The energy for this process comes from cellular respiration in mitochondria, stored in ATP molecules. The tutorial also discusses active transport in plants, specifically in root hair cells, which absorb water and minerals from the soil. These cells are adapted with a large surface area and numerous mitochondria to facilitate active transport.

What is the main difference between diffusion and active transport?

• Diffusion is a passive process, while active transport requires energy.

• Diffusion requires energy, while active transport does not.

• Active transport occurs without a membrane, while diffusion requires a membrane.

• Active transport moves substances down their concentration gradient, while diffusion moves them against it.

Which of the following is necessary for active transport to occur?

• A large surface area

• The presence of chlorophyll

• Energy from cellular respiration

• A concentration gradient moving from high to low

Where does the energy for active transport primarily come from?

• Osmosis in the cytoplasm

• Diffusion across cell membranes

• Cellular respiration in mitochondria

• Photosynthesis in chloroplasts

What adaptation helps root hair cells absorb mineral ions effectively?

• Presence of chlorophyll

• Large surface area and many mitochondria

• Thick cell walls

• High concentration of glucose

Why can't plants absorb certain minerals by diffusion?

• The minerals are too large to pass through the cell membrane.

• Diffusion requires energy, which the plant lacks.

• The minerals are at a higher concentration inside the cell.

• The minerals are at a higher concentration outside the cell.