2025 Ecosystem Test

What is the main purpose of photosynthesis?

• To help plants absorb water
• To convert sunlight into food energy
• To allow plants to breathe
• To protect plants from animals

Which of the following is NOT needed for photosynthesis to occur?

• Carbon dioxide
• Sunlight
• Oxygen
• Water

What part of the plant is mainly responsible for photosynthesis?

• Roots
• Stem
• Flowers
• Leaves

What gas do plants take in during photosynthesis?

• Oxygen
• Nitrogen
• Carbon dioxide
• Helium

What is a product (something made) of photosynthesis?

• Salt
• Glucose
• Carbon dixoide
• Soil

Read the descriptions of each of the organisms to learn about their diet and then use the information to choose the correct food chain.

• diatom--->herring--->grebe--->mushroom
• diatom--->alpine avens---> raven--->wolf
• birch--->redpoll--->merlin--->mushroom
• birch--->herring--->killer whale--->seal

What is the limiting factor in the following scenario? In a grassy African savanna, a large population of zebras lives and feeds on the tall grasses. During the rainy season, the grass grows quickly, and the zebra population thrives. However, one year, a severe drought hits the region. The rain doesn’t come for months, and the grass stops growing. As the food becomes scarce, some zebras begin to starve, and the population starts to decrease. Lions, which prey on zebras, are also affected. With fewer zebras around, the lions struggle to find enough food.

• The number of lions
• The amount of grass
• The temperature of the air
• The number of tree

How did the drought affect the zebra population in the following scenario: In a grassy African savanna, a large population of zebras lives and feeds on the tall grasses. During the rainy season, the grass grows quickly, and the zebra population thrives. However, one year, a severe drought hits the region. The rain doesn’t come for months, and the grass stops growing. As the food becomes scarce, some zebras begin to starve, and the population starts to decrease. Lions, which prey on zebras, are also affected. With fewer zebras around, the lions struggle to find enough food.

• It made more predators move into the area
• It caused the grass to grow faster
• It reduced the amount of food, so some zebras starved
• It increased the number of watering holes

How does a decrease in the zebra population affect other animlas in the ecosystem in the following scenario: In a grassy African savanna, a large population of zebras lives and feeds on the tall grasses. During the rainy season, the grass grows quickly, and the zebra population thrives. However, one year, a severe drought hits the region. The rain doesn’t come for months, and the grass stops growing. As the food becomes scarce, some zebras begin to starve, and the population starts to decrease. Lions, which prey on zebras, are also affected. With fewer zebras around, the lions struggle to find enough food.

• Lions have more zebras to hunt
• Lions may struggle to find enough food
• The grass grows even slower
• Zebras start eating meat instead of grass

What does the term carrying capacity mean in this scenario? In a forest, a population of 100 deer feeds on grass, shrubs, and leaves. The forest has enough food, water, and space to support about 100 deer. Over time, the deer reproduce, and the population grows to 150. At first, the deer are healthy, but soon the plants begin to disappear faster than they can grow back. Some deer begin to lose weight because there isn’t enough food for everyone. As more deer compete for less food, many become weak or die, and the population drops back to around 100. This cycle of growth and decline continues over time, keeping the deer population near a certain number that the environment can support.

• The number of deer that can fit in one area
• The amount of food one deer can eat in a day
• The largest number of deer the forest can support long-term
• The number of predators living in the forest