EOG 8th Grade Science Part 2

How has biotechnology helped to improve the agricultural industry?

• by developing irrigation systems that cover a large land area

• by creating some crops that resist certain insects

• by producing soil free of decomposers

• by developing machines that help farmers harvest crops faster

Answer explanation

Remember: Bio technology aids in living organisms by genetically modifying them to be resistant to certain things.

The table shows the food choices for two species of birds. Which will most likely happen to Questors as a result of Wood Plaxers migrating to their habitat?

• The Questors will compete with the Wood Plaxers for food resources.

• The Questors will be forced to fly to a different habitat.

• The two species will become extinct.

• The two species will coexist with no competition.

Answer explanation

They would co-exist because they will not compete for food

What happens to most of the energy as it moves throughout a food web?

• It is changed into light energy.

• It is changed into heat energy.

• It is changed into mass

• It is changed into decomposers.

Answer explanation

heat is always released and lost to the environment.

Which is the best evidence for evolution?

• new rock layers containing fossils of simple organisms

• new rock layers containing fossils unlike existing organisms

• old rock layers containing fossils unlike existing organisms

• old rock layers containing fossils of complex organisms

Answer explanation

old rock layers with organisms the are unlike any existing organism means that past years had similar organisms but they are unlike any existing organisms.

Which best explains why mammals became dominant after the mass extinction of the dinosaurs?

• They had traits that helped them adapt to environmental changes

• They were larger than dinosaurs and ate different foods.

• They lived in different areas on Earth than dinosaurs.

• They were able to hibernate for thousands of years.

Answer explanation

Mammals were able to adapt to the environmental changes that happened to the climate (aka climate change)

Which demonstrates how genetic variation may result from a change in the environment where an animal lives?

• A salmon swims faster as it enters colder waters.

• A snake increases its body temperature because it moves on top of a rock in direct sunlight

• A beetle stands out to predators because it moves among plants that have colors different than its own.

• An arctic fox changes its color over time because it migrates to an area with a different climate

Answer explanation

ADAPTATION!!!!!

Where do plants get the food they need for energy?

• They absorb it directly from the sun

• They absorb it directly from the soil

• They produce it during photosynthesis

• They receive it from atmospheric gases

Answer explanation

Photosynthesis is the process of creating its own energy and food by absorbing sunlight and combining sunlight with co2, water, and other organic materials.

Chlorine has 7 valence electrons. With what group of elements will chlorine most readily bond?

• group 1

• group 2

• group 17

• group 18

Answer explanation

any element that has 7 valence electrons only needs 1 more valence electron to fill its outer shell!

Which is the best example of a chemical change?

• butter melting

• egg cooking

• paper tearing

• water evaporating

Answer explanation

cooking aids in chemical reactions.

Which chemical equation best represents the Law of Conservation of Mass?

• H + O → H2O

• H2 + O2 → H2O

• 2H2 + O2 → 2H2O

• H2 + O2 → 2H2O2

Answer explanation

Law of conservation of mass states that the reactants mass = mass of products.