PBA 2 Review Quiz

What are the inputs for photosynthesis?

• Sunlight, carbon dioxide, and water

• Carbon monoxide, sunlight, and soil

• Sunlight, oxygen, and minerals

• Oxygen, glucose, and nitrogen

Answer explanation

The inputs for photosynthesis are sunlight, carbon dioxide, and water. These elements are essential for plants to convert light energy into chemical energy, producing glucose and oxygen as byproducts.

What are the outputs for photosynthesis?

• Carbon dioxide and water

• Nitrogen and glucose

• Oxygen and carbon dioxide

• Glucose and oxygen

Answer explanation

The outputs of photosynthesis are glucose and oxygen. During this process, plants convert carbon dioxide and water into glucose for energy and release oxygen as a byproduct.

Which of the following is a primary consumer in a food chain?

• Grass

• Rabbit

• Hawk

• Mushroom

Answer explanation

In a food chain, primary consumers are organisms that eat producers. Grass is a producer, mushrooms are decomposers, and hawks are predators. Rabbits eat grass, making them primary consumers.

What role do decomposers play in an ecosystem?

• They produce energy from sunlight.

• They consume primary producers.

• They break down dead organisms and recycle nutrients.

• They compete with primary consumers for food.

Answer explanation

Decomposers play a crucial role in ecosystems by breaking down dead organisms, which recycles nutrients back into the soil. This process supports plant growth and maintains the balance of the ecosystem.

Which of the following best describes the process of photosynthesis?

• Conversion of glucose into energy

• Conversion of sunlight into chemical energy

• Conversion of oxygen into carbon dioxide

• Conversion of water into oxygen

Answer explanation

Photosynthesis is the process where plants convert sunlight into chemical energy, specifically in the form of glucose. This distinguishes it from other processes like respiration or gas exchange.

Identify the type of consumer: A lion that eats a zebra.

• Herbivore

• Carnivore

• Omnivore

• Decomposer

Answer explanation

A lion is a carnivore because it primarily eats meat, such as zebras. Herbivores eat plants, omnivores eat both plants and animals, and decomposers break down dead organic matter. Therefore, the correct answer is carnivore.

Which factor is most likely to cause a population to increase?

• Increased predation

• Abundant food supply

• Limited habitat space

• High disease rate

Answer explanation

An abundant food supply provides the necessary resources for a population to grow, as it supports reproduction and survival. In contrast, increased predation, limited habitat space, and high disease rates would hinder population growth.

In a food chain, which organism is typically at the top?

• Producer

• Primary consumer

• Secondary consumer

• Apex predator

Answer explanation

In a food chain, the apex predator is at the top, as it has no natural enemies and preys on other organisms. Producers and consumers are lower in the hierarchy, making the apex predator the highest level.

Which of the following is an example of a food chain?

• Grass → Rabbit → Fox

• Sun → Water → Soil

• Tree → Mushroom → Soil

• Fish → Algae → Water

Answer explanation

The correct choice, 'Grass → Rabbit → Fox', illustrates a food chain where energy flows from grass (producer) to rabbit (primary consumer) and then to fox (secondary consumer), demonstrating the transfer of energy in an ecosystem.

What is the main source of energy for producers in an ecosystem?

• Water

• Soil

• Sunlight

• Oxygen

Answer explanation

The main source of energy for producers, such as plants, is sunlight. They use photosynthesis to convert sunlight into chemical energy, which fuels their growth and sustains the ecosystem.