Grade 3 Science Practice Test: Traits, Fossils and Environments

A language is learned by hearing and practicing it; nobody is born speaking one. Hair type, eye color and dimples are passed from parents to children through inheritance.

Offspring get traits from both parents, so the kittens are similar to their parents and to each other. They are still not identical: there is variation, so one kitten may be gray, another black, and their sizes and markings can differ.

The flamingo's color changed because of its food, which is part of its environment. Many traits come from parents, but some, like this color, can also be influenced by the environment. The flamingo does not choose its color.

Strength gained from exercise is caused by what a person does during life, so it is not inherited. His children do inherit other traits from him, such as hair color, so the claim that children never inherit traits from fathers is false.

A fossil is the preserved remains or trace of a living thing from long ago, often found in rock. The leaf print qualifies. A fresh leaf and a shell in use today are not from long ago, and a pebble was never part of a living thing.

Footprints are trace fossils. Their size, shape and spacing show how large the feet were, how many toes the animal had and how it moved. Footprints cannot show skin color, sounds or what the animal ate.

Plants that need warm weather could only have grown there if the place was once much warmer. Fossils of living things show what an environment was like when they lived, so the area has changed a lot over a very long time.

When a kind of living thing dies out completely, it is extinct. Fossils of animals unlike any living animal, such as many dinosaurs, show that some kinds of organisms lived long ago and no longer exist.

A frog that can bury itself in mud has a way to wait out the dry season. A fish and a water lily need to stay in water, and a duckling that cannot fly cannot leave to find water somewhere else.

Plants with many thorns are eaten less, so more of them survive and make seeds. Their offspring inherit the trait of many thorns, so over many years a larger share of the plants in the field will be thorny.

Living in a group can help animals survive. A predator facing a large, moving school has trouble picking out one fish, and many eyes can spot danger sooner. Swimming in a group does not change how fish breathe or how big they grow.

When an environment changes, some organisms move to a new place, some survive in smaller numbers and some die. Woodpeckers need trees for nesting, so many will leave or fail to raise young. Birds cannot change into a different kind of animal.

White fur blends in with snow, so foxes, lynx and owls have a harder time seeing the hare. This camouflage gives the hare a better chance to survive and reproduce. Fur color does not help it run or find food.

Amber keeps the shape of the insect, often down to its legs and wings, so scientists can see what insects from long ago looked like and compare them with insects today. The fossil cannot record sounds, and it says nothing about future weather.

Petal color is passed from parent plants to their offspring through seeds. A bent stem, chewed leaves and drooping leaves are caused by things in the environment during the plant's life, so they are not inherited.