Give a reason why primary productivity in an aquatic Ecosystem decreases with depth.

Here are the answers to the questions:

Question 9:
Give a reason why primary productivity in an aquatic ecosystem decreases with depth.

Primary productivity in aquatic ecosystems relies on photosynthesis. As depth increases, the amount of sunlight penetrating the water decreases significantly. Since sunlight is essential for photosynthesis, the rate of primary productivity, carried out by producers like phytoplankton, declines with depth due to insufficient light.

Question 10:
State TWO functions of the substance secreted by sebaceous glands.

The substance secreted by sebaceous glands is sebum.

1. Sebum lubricates the skin and hair, preventing them from drying out and becoming brittle.
2. Sebum has antibacterial and antifungal properties, forming a protective barrier against pathogens on the skin surface.

Question 11 a):
What is homeostasis?

Homeostasis is the process by which living organisms maintain a stable internal environment despite changes in external conditions. This involves regulating various physiological factors such as temperature, pH, and blood glucose levels within narrow limits to ensure optimal functioning.