Plant roots are adapted to absorb water and mineral ions | Combined science

Starter quiz

Water is needed by plants for photosynthesis. Where do plants get this water from?

Leaves absorb rainwater through stomata.

Roots absorb water from the soil. ✓

Flowers absorb water when it rains.
Which subcellular structure in plant cells is the site of photosynthesis?

'chloroplasts' ✓
Which gas in air is needed for photosynthesis?

carbon dioxide ✓

nitrogen

oxygen

argon
Which gas made by photosynthesis is excreted by leaves during daylight?

'oxygen' ✓
Match each word to its correct meaning.

active transport

⇔

use of energy to move particles against a concentration gradient ✓

diffusion

⇔

net movement of particles from a region of high to lower concentration ✓

concentration gradient

⇔

a difference in concentration of particles from one region to another ✓

osmosis

⇔

the diffusion of water molecules through a membrane ✓
During active transport, a ______ protein in the cell membrane changes shape to transport particles through the membrane against a concentration gradient.

'carrier' ✓

Exit quiz

Which is the correct word summary for photosynthesis?

carbon dioxide + water --> glucose + oxygen ✓

oxygen + glucose --> water + carbon dioxide

water + glucose --> carbon dioxide + oxygen

carbon dioxide + glucose --> water + oxygen
Water can leave the plant via pores in the leaves called ______.

'stomata' ✓
Match each mineral to how it is used by plants.

magnesium

⇔

to make chlorophyll ✓

nitrogen

⇔

needed to make amino acids ✓

phosphates

⇔

needed to make nucleotides ✓
Match each substance to how it is absorbed by plants.

water

⇔

osmosis ✓

carbon dioxide

⇔

diffsion ✓

nitrate

⇔

active transport ✓
The ‘hair’ of a root hair cells is what distinguishes it from other root cells. How does the hair adapt a root hair cell for its function?

It increases the transfer of energy for active transport.

It increases the concentration gradient to speed up osmosis.

It increases the surface area to speed up diffusion. ✓

It increases the ability of a cell to move.
The diagram shows a root hair cell with many mitochondria. What is the function of mitochondria?

to speed up diffusion

to speed up osmosis

the site of photosynthesis

the site of aerobic cellular respiration ✓

Worksheet

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Lesson Details

Key learning points

Plants need water for support (to remain turgid) because they don’t have bones, and for photosynthesis in cells.
Plants need mineral ions for growth and repair, including nitrate ions as a source of nitrogen to make proteins.
Particles of water are absorbed by osmosis, a type of diffusion, into plant root hair cells.
Nitrate ions are absorbed into plant root hair cells by active transport, which requires energy.
Root hair cells are adapted to increase the surface area of membrane for osmosis and active transport.

Common misconception

Some students do not realise the significance of the shape of the root hair cell and do not explain this in terms of increasing its surface area.

The idea of surface area as the significant adaptation of root hair cells is clearly introduced, checked, and reinforced with specific tasks that explicitly enquire about this adaptation.

Keywords

Osmosis - the net movement of water molecules through a selectively-permeable membrane from high to low concentration of water molecules
Net movement - the overall movement of particles
Active transport - the net movement of particles against a concentration gradient using energy
Concentration gradient - a difference in the concentration of particles from one area to another
Root hair cell - a specialised plant cell found in the roots that absorb water and nutrients into the plant