Figure 6 shows a root hair cell from a strawberry plant - Edexcel - GCSE Biology - Question 3 - 2020 - Paper 1

The structure of root hair cells is specialized for water absorption due to several key features. Firstly, root hair cells have long and thin projections, which increase the surface area available for interaction with soil particles. This increased surface area allows more water molecules to be absorbed efficiently. Additionally, the cell wall of root hair cells is thinner compared to other types of cells, resulting in a shorter distance for water to travel into the cell. Consequently, this optimizes the absorption process and enhances water uptake from the surrounding soil.

To calculate the mean rate of growth of fungus at 30 °C, we substitute the area of fungus at 30 °C into the provided information. The area is 72 cm² after 5 days. Therefore, the mean rate of growth is calculated as:

$\text{Mean rate} = \frac{72 \text{ cm}^2}{5 \text{ days}} = 14.4 \text{ cm}^2 \text{ per day}$

The growth or area of fungus increases with temperature, indicating that as the temperature rises from 5 °C to 30 °C, the fungus grows more rapidly.

Boiling denatures the enzymes present in the fungus. Enzymes are heat-sensitive proteins that require specific conditions to function effectively. When heated to high temperatures, the three-dimensional structure of the enzyme changes, disrupting the active site where substrate molecules bind. As a result, the substrate(s) cannot properly fit into the active site, effectively stopping the enzymatic reactions and thus preventing decomposition.

Osmosis causes water to move out of the fungus cells due to the concentration gradient between the sugar solution in the jam and the fungus cells. Since the sugar solution inside the jam is more concentrated than that inside the fungus cells, water from the cells moves out into the jam solution. Consequently, this leads to dehydration of the fungus cells, ultimately causing them to die.