Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

Grade 8 Biology Review Question

Part 1:

1. What are the characteristics of living things?Answer:

• Made of cells• Take in nutrients• Use energy• Produce waste that must be removed• Respond to stimuli• Grow• Reproduce

2. How are unicellular and multicellular living things similar and different?

A: Both have all the characteristics of living things. Unicellular organisms have structures to carry out life processes, whereas multicellular organisms have structures and systems. Cells can only grow up to a certain point, then an increase in the number of cells is needed to increase the size of the organism.

3. Living things get their food in different ways. Give an example of a consumer and an example of a producer.

A: Producer: plants, photosynthetic microorganisms (phytoplankton), example dogwood tree. These organisms produce their own sugar using energy from the sun, water, and carbon dioxide.

Consumer: Living things that eat other organisms to get nutrients. Examples: deer, bear, rabbit.

4. Choose an organism and describe how it responds to external and internal stimuli.

A: Example: human. If you are hungry/thirsty (internal stimulus) you eat/drink. If you hear your name, you turn and look/listen (external stimulus).

5. Which characteristic of living things is described in each statement?- Humans breathe out carbon dioxide when they exhale.

A: produce waste

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

- A bacterium split in two equal halves to produce two new daughter cells.A: reproduce

- A tadpole undergoes metamorphosis and becomes a bullfrog.A: grows and develops

- A raft of Stellar sea lions consume fish, squid, and octopus as part of their diet.A: Take in nutrients

- A chemical reaction inside a lizard’s cells releases energy so that it can run and jump.A: Use energy

- A Western rattlesnake coils up on the road to bas kin the sun so that it can stay warm.A: responds to stimuli

- Under a microscope, some internal leaf structures are arrange like bricks in a wall.A: made of cells

6. Which two characteristics of living things are interdependent because they are closely related in the statement below:

A tree absorbs nutrients and water from the soil, takes in carbon dioxide from the atmosphere, and captures the Sun’s energy to produce food and oxygen through the process of photosynthesis?

A: Take in nutrients and produce waste

7. Which of the following organisms relies on other organisms for energy and nutrients?a. Mossb. Algaec. Apple treed. Snowy Owl

8. Hunger and thirst are examples of a. Life processesb. Internal stimulic. External stimulid. Sources of energy

9. Explain what the three parts of the cell theory mean.a) The cell is the basic unit of life. A: All living things are made up of one or more cellsb) Cells come from pre-existing cells. A: Living things reproduce through the reproduction

of cellsc) All living things are made up of one or more cells. A: All living things are either

unicellular or multicellular

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

10.

1. A2. E3. D4. F5. G6. B7. C

11. Why do many scientists not consider viruses to be alive?

A: The do not use energy, produce waste, and they can only reproduce by infecting a host cell. They cannot carry out life processes (take in nutrients, reproduce) on their own.

12. What does a virus depend on for reproducing more viruses?a. A fatty coatb. Cellular proteinsc. Genetic material d. A carbohydrate membrane

*Apology for the mistake here. Answer should be: “living cells”. In living cells, the virus hijacks cellular processes as viral DNA is copied and used to reproduce.

Question: Which of the following structures do all viruses have in common?

a. A fatty coatb. Cellular proteinsc. Genetic material d. A carbohydrate membrane

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

13. What are two differences between prokaryotic and eukaryotic cells?

A: Prokaryotic cells: smaller, simpler, no nucleus, simple structures

A: Eukaryotic cells: larger, have organelles, more complex

14.

A: Cell membrane: controls what goes in and out of the cell; BothCell wall: provides structural support for the cell; PlantNucleus: controls the cell’s life sustaining activities; BothChloroplast: captures the Sun’s energy to convert it into food for the plant; PlantMitochondria: produces energy for the cell; BothVesicles: transports materials that enter and leave the cell; Both

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

Vacuole: stores food, waste, and water; BothCytoplasm: gives the cell its shape and holds the organelles in place; Both

15. Are plant and animal cells examples of prokaryotic or eukaryotic cells?A: eukaryotic cells

Cell Analogy:

Cell Structure Is like Because….The cell membrane The ticket booth It controls who gets in to see

the movie by allowing only people with purchased tickets to enter the theatre

The cell wall The walls of the movie theatre

It provides structural support and protects the inside of the movie theatre

The cytoplasm The aisles and corridors in the movie theatre

It allows the customers and employees to move around the movie theatre

The chloroplasts The food counter It produces popcorn and food for the customers

The nucleus The administrative office It controls the operations of the movie theatre

The vesicles The popcorn bags and cups They store and carry around food and drinks

The vacuoles The storage closet They store all the equipment and supplies necessary to run a movie theatre

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

16. Which organelles are found in plant cells but not animal cells?

A: chloroplast and cell wall

17. What are the waste products of photosynthesis?

A: Oxygen is waste. Sugar is also produced but it is not waste- it stores energy for the cell.

18. Does cellular respiration occur in plant cells, animal cells, or both?

A: Both

19. A Euglena is a unicellular organism that is able to produce its own food because of the presence of many green organelles in its cytoplasm. Which of the following can you infer about Euglena based on the information given?

I It is a prokaryotic cell.II It is a photosynthetic organisms.III It has the green pigment chlorophyll.

a. I and II onlyb. I and III onlyc. II and III only d. I, II, and III

20. Why are photosynthesis and cellular respiration complementary processes?

A: Photosynthesis uses carbon dioxide, water, and light energy to produce sugar and oxygen. Cellular respiration, is a chemical reaction that uses oxygen and sugar, and produces carbon dioxide and water. The products of one process are used as reactants in the other process. Photosynthesis stores energy from the sun in chemical form and cellular respiration releases the chemical energy.

21. What are 5 ways microbes are beneficial to humans?A: See notes. Examples: some microorganism are useful for medicine, probiotics/digestion, waste management, disaster cleanup, fermented foods, soil/agriculture, their ecological role as decomposers.

22. Which of the following does not describe a pathogen?a. It is usually harmless

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Date:____________________________ Name:_____________________________Grade 8 Biology Unit Review Questions

b. It can make people sickc. It is a disease-causing agentd. It can produce toxins or poison

23. Which of the following cells is prokaryotic and which is eukaryotic?

A: Prokaryotic A: Eukaryotic

24. Which of the following cells is a plant cell and which is an animal cell?

A: Animal A:Plant

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