Life Science

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3rd Grade Science › Life Science

Questions 1 - 10
1

All organisms follow a life cycle, even humans. In the model below, what is the missing piece of the cycle?

Newborn Infant Child                          Adult Elderly

Toddler

Teenager

Baby

Senior Citizen

Explanation

The missing stage of this life cycle model is "Teenager." All organisms move through life on a similar path from birth to death. In the cycle presented, this person has not completed their teenage years, which comes before being an adult. Different organisms have their specific periods, so it may look different when comparing an insect and a plant.

2

Sasha planted huge shrubs and trees in her backyard to give her privacy from her neighbors. She created lots of shade to sit in on hot summer days. What she didn't realize was that all of the darkness was hurting her smaller plants. They are supposed to be green and stand straight, but now they are wilting and brown.

What traits have changed with the smaller plants?

Root size and flowers

Plant shape and color

Leaf age and hobbies

Stem color and leaf shape

Explanation

Plants inherit traits from their parents, including their stem color, shape, leaf texture, flower color, and stem shape. Due to the shade from the tall shrubs and trees, the plants are no longer straight, green plants like their parents but instead brown and wilting. The environmental impact on the plant's traits has caused it to change, and its appearance has been altered.

3

Fruit and vegetable plants rely on pollinators to spread pollen from flower to flower for reproduction. To make new plants, the pollen has to be transported.

What changes may occur to the plants if there are no pollinators?

There will eventually be no plants because they cannot reproduce without the pollinators.

There will be more plants because they don't have to worry about pollinators eating them.

The plants would not be affected by pollinators disappearing.

The plants will grow weaker because there are no pollinators to bring them food.

Explanation

Plants rely on pollinators for reproduction. Bees, bats, hummingbirds, and other pollinators will move from flower to flower, and the pollen will get stuck to them. When they land on the next flower, the dust will transfer. Seeds are spread, and new plants form. Without pollinators, there would be significant consequences for the plant's future. Eventually, there will be no more fruit and vegetable plants because of the lack of pollinators.

4

Gordon Hubbell and a crew of fossil hunters were digging holes in the desert of Peru in 1988. This desert is one of the driest places on Earth. It gets almost no rain. Hubbel was digging and found jawbones and more than 200 sharp teeth. He is an expert in fossilized sharks, so he recognized the teeth right away. They were shaped like triangles and came to a very sharp point. They belonged to a distant relative of the great white shark!

How could Hubbell "prove" that these teeth were from a relative of the great white shark?

Show a fossilized tooth and a great white shark tooth next to each other so people can see the similarities.

There is no way to prove where these teeth came from, so he can only make a claim.

Hubbell can dig for other fossilized teeth and show people how many there are in this area.

Hubbell can compare the tooth to all of the fossils ever found and show people that this one is different.

Explanation

Hubbell is an expert in fossilized sharks, so he recognized the similarities between his find and great white shark teeth, but others may need "proof" before they would believe him. If Hubbell placed a great white shark's tooth next to his fossil, the similarities and differences could be noted. By comparing the teeth, it would allow scientists to determine what creature it belonged to with certainty.

5

Use evidence from the data table to explain the environmental impact on the traits of the wheat plant.

Screen shot 2020 06 09 at 3.45.14 pm

Using less water causes the plants to be taller

Using more water causes the plants to be taller

Using more water causes the plants to be shorter

The amount of water does not affect a plant's height

Explanation

Environmental factors can have an impact on the traits of plants and animals. In the case of this farmer's wheat plants, the more water the field received, the taller the plant is. The data table provides evidence to support this claim and the impact that water has on the traits of a plant.

6

How would a dog's weight be impacted if all they ate lots of treats and never exercised?

They may be overweight.

They may be underweight.

They may grow very tall.

They may be very short.

Explanation

Environmental factors influence traits in plants and animals. These traits include things like weight, height, size, and color. If a dog does not get proper nutrition and exercise, their weight will be negatively impacted. The dog is likely to be overweight if the environmental factors are not changed. Without the right vitamins, nutrients, and exercise, they may not reach their inherited potential due to environmental influences.

7

Fruit and vegetable plants rely on pollinators to spread pollen from flower to flower for reproduction. To make new plants, the pollen has to be transported.

What changes may occur to the plants if there are no pollinators?

There will eventually be no plants because they cannot reproduce without the pollinators.

There will be more plants because they don't have to worry about pollinators eating them.

The plants would not be affected by pollinators disappearing.

The plants will grow weaker because there are no pollinators to bring them food.

Explanation

Plants rely on pollinators for reproduction. Bees, bats, hummingbirds, and other pollinators will move from flower to flower, and the pollen will get stuck to them. When they land on the next flower, the dust will transfer. Seeds are spread, and new plants form. Without pollinators, there would be significant consequences for the plant's future. Eventually, there will be no more fruit and vegetable plants because of the lack of pollinators.

8

Environmental changes cannot cause problems for animals.

True

False

Explanation

This is a false statement. Environmental changes can cause significant problems for animals. If humans cut down a forest to build a new neighborhood, animals are displaced, maybe without homes, or food sources are lost. These would be terrible changes to the environment that would have long-lasting effects on animals.

9

Polar bears hunt seals through holes in the sea ice. They travel from great distances across sheets of frozen water to find seal colonies. The seals rest on the ice in large groups and raise their pups. When the seals go out to hunt fish they slip into the water from the edge of the ice.

If temperatures rise and the ice begins to melt, what impact could there be for the seals?

Melting sea ice and warmer temperatures means the seals will become better swimmers.

Warmer temperatures and melting sea ice would not impact seals.

Seals would not have places to raise their pups and would be exposed to bears.

The temperature warming and ice melting would mean more summer fun for seals.

Explanation

Animals may have to change when there are environmental changes that impact their lives. In the case of the seal dealing with the difference in the amount of sea ice, the change would need to be huge to survive. Seals rely on the sea ice for raising their pups and escaping polar bears, so they would either need to adapt and change their offspring-rearing techniques or find another place to live. These changes would be challenging, and the seals may not survive.

10

Which scenario below is an example of plants being affected by an environmental change?

Amelia gets a new potted plant from the store and adds it to her collection.

Robert gives his wife a bouquet of roses for their wedding anniversary.

Cindy throws away the dead leaves from a house plant.

Johnny's tomato plants withered and died during a drought.

Explanation

All of these scenarios feature plants, but only one highlights a change in the environment, which in turn affects the plants. The tomato plants were deprived of water due to the drought, so they withered and died. Plants need water to survive, and the change in the environment negatively affected the tomato plants.

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