Question

1. what is the primary role of primary producers in a marine food web?

a) to break down organic matter
b) to capture solar energy and produce food
c) to consume other organisms
d) to act as top predators

1. in a marine food web, which of the following organisms would be considered a secondary consumer?

a) phytoplankton
b) zooplankton
c) small fish that eat zooplankton
d) sea cucumbers

1. what are the apex predators in a marine food web known as?

a) tertiary consumers
b) primary consumers
c) secondary consumers
d) decomposers

1. which trophic level includes organisms like bacteria and fungi?

a) primary producers
b) primary consumers
c) secondary consumers
d) decomposers

1. what is one of the main consequences of overfishing in marine ecosystems?

a) increased biodiversity
b) enhanced habitat restoration
c) improved water quality
d) collapse of fish populations

Explanation:

1. Primary producers, like phytoplankton, use photosynthesis to capture solar energy and produce food (organic matter) through photosynthesis. This forms the base of the food web.
2. In a marine food web:

• Phytoplankton (a) are primary producers.
• Zooplankton (b) are primary consumers as they eat phytoplankton.
• Small fish that eat zooplankton (c) are secondary consumers (they eat primary consumers).
• Sea cucumbers (d) are often detritivores or decomposers - like organisms.

1. Apex predators are at the top of the food chain. Tertiary consumers (a) are often apex predators as they are above secondary and primary consumers in the trophic levels. Primary consumers (b) eat producers, secondary consumers (c) eat primary consumers, and decomposers (d) break down dead organic matter.
2. Bacteria and fungi break down dead organisms and waste. Decomposers (d) are responsible for this process. Primary producers (a) make food, primary consumers (b) eat producers, and secondary consumers (c) eat primary consumers.
3. Overfishing means catching too many fish. This leads to a decrease in fish populations. If the fishing pressure is too high, it can cause the collapse of fish populations (d). Increased biodiversity (a), enhanced habitat restoration (b), and improved water quality (c) are not consequences of overfishing. Overfishing can disrupt the food web (affecting biodiversity negatively), damage habitats (e.g., through trawling), and not improve water quality (as it can lead to imbalances in the ecosystem).

Answer:

1. B. To capture solar energy and produce food
2. C. Small fish that eat zooplankton
3. A. Tertiary consumers
4. D. Decomposers
5. D. Collapse of fish populations