Why is self-pollination disadvantageous for a species?

14. (b) Disadvantages

• Self-pollination leads to reduced genetic variation, making the offspring less adaptable to environmental changes.
• It increases the chances of expressing undesirable recessive traits, which can weaken the population over generations.

Question about Lactase

(a)

$$\text{Lactose} + \text{Water} \longrightarrow \text{Glucose} + \text{Galactose}$$

(b)
The type of chemical reaction shown in this equation is hydrolysis.

(c) (i)
To distinguish between a solution of the enzyme lactase and a solution of lactose using the Biuret test:
Add a few drops of sodium hydroxide solution to each sample, followed by a few drops of dilute copper(II) sulfate solution. Shake gently after each addition.

(c) (ii)
With the enzyme (lactase), the solution would turn purple. This is because lactase is a protein, and the Biuret test detects peptide bonds present in proteins.

Which substance is lost from the body by the kidneys, lungs and skin?
The substance lost is water.

Diagram shows blood vessel P
Blood vessel P is the hepatic portal vein.