Grade by Grade
B. Life Systems · Cells

Cells: Unit Review

A1.1 A1.2 A1.3 A1.4 A1.5 A2.1 A2.2 A3.1 A3.2 A3.3 B1.1 B1.2 B2.1 B2.2 B2.3 B2.4 B2.5 B2.6About 40 minutes
Learning goals
  • I can explain the cell theory and how microscopes and other technologies helped us understand cells.
  • I can identify the parts of plant and animal cells, explain their jobs and compare the two cell types.
  • I can explain diffusion and osmosis in cells.
  • I can compare unicellular and multicellular organisms and describe how cells form tissues, organs and systems.
  • I can analyse benefits and harms of developments in cell biology from different perspectives.

Words to know

cell theory
All living things are made of cells; the cell is the basic unit of life; all cells come from existing cells.
organelle
A small structure in a cell with a special job.
diffusion
Particles moving from higher to lower concentration.
osmosis
Diffusion of water through a selectively permeable membrane.
tissue
A group of similar cells working together.
organ
Several tissues working together.
stem cell
An unspecialized cell that can become different kinds of cells.

Let's review!

In this unit you learned the cell theory, how microscopes and other technologies revealed cells, the organelles of animal and plant cells, how substances move into and out of cells by diffusion and osmosis, how unicellular and multicellular organisms meet their needs, how cells form tissues, organs and systems, how to keep cells healthy, and how to weigh the benefits and harms of developments in cell biology.

This review has a few questions from every lesson. Try each one, then press Show answer to check. If a part feels tricky, go back to that lesson for more practice.

Plant cellAnimal cellcell wallchloroplastslarge centralvacuolebox-like shapenucleuscell membranecytoplasmmitochondriasmall vacuolesor noneflexible shapeno cell wallBoth
Plant and animal cells share four parts (middle). Only plant cells have a cell wall, chloroplasts and a large central vacuole.
DiffusionOsmosisparticles: high → low concentrationwater moves toward more dissolved stuffwaterparticles of dye, salt or sugar
Diffusion and osmosis side by side. In diffusion, particles spread from high to low concentration. In osmosis, water moves through a membrane toward the side with more dissolved stuff.

Cell Theory: What Every Living Thing Has in Common

1

State the three main ideas of the cell theory.

2

Who named cells, and what was he looking at?

3

Is a piece of pine wood made of cells? Explain.

Using a Microscope: Parts, Magnification and Scientific Drawings

1

A 10× eyepiece and a 40× objective give what total magnification?

2

On low power the field of view is 4 mm. 10 cells fit across. How big is each cell, in µm?

3

Which focus knob do you use on high power?

Seeing Smaller: How Technology Opened Up the World of Cells

1

Why can't a light microscope show a virus?

2

A photo of a cell is 30 mm wide at 600× magnification. How wide is the real cell?

3

Give one limitation of electron microscopes.

Inside an Animal Cell: Organelles and Their Jobs

1

Which organelle holds DNA and controls the cell?

2

What do mitochondria do?

3

What does the cell membrane do?

Plant Cells and How They Compare to Animal Cells

1

Name the three structures plant cells have that animal cells don't.

2

Do plant cells have mitochondria?

3

Why does a plant wilt when it's dry?

Diffusion: How Substances Move Into and Out of Cells

1

Which way does oxygen diffuse between blood and a body cell? Why?

2

Name two factors that speed up diffusion.

3

Does diffusion use the cell's energy?

Osmosis: Water on the Move

1

What happens to a red blood cell in pure water?

2

What happens to a plant cell in very salty water?

3

A potato strip goes from 20.0 g to 18.0 g. Percent change? Was it in salty or tap water?

Unicellular and Multicellular Organisms: Meeting Basic Needs

1

How does a paramecium get rid of extra water?

2

What is the surface area to volume ratio of a 3 cm cube?

3

Starting with 1 bacterium that doubles every 20 minutes, how many after 100 minutes?

Specialized Cells and Tissues

1

Name the four main animal tissues.

2

What does xylem carry? Phloem?

3

How does a root hair cell's shape help it?

From Cells to Organisms: Organs and Organ Systems

1

Put in order: organ system, cell, organism, tissue, organ.

2

Is a leaf a tissue or an organ? Explain.

3

Name two human systems that work together to deliver oxygen to cells.

Keeping Cells Healthy: Cell Division, Cancer and Microbes

1

What is cancer?

2

Why don't antibiotics cure the flu?

3

Name two ways to protect skin cells from UV.

Cell Biology Breakthroughs: Weighing Benefits and Harms

1

Give one benefit and one harm of antibiotics.

2

What are OCAP® principles about?

3

Name two perspectives to consider about GM crops.

Just for fun

Why did the cell ace the unit test?

It was finally organelle-ized.

How to use this review

  • Try every question before you look at the answer, and write your answers down.
  • Mark the ones you got wrong or weren't sure about. Go back to that lesson, reread the explanation and examples, and redo its practice.
  • For cell parts, practise drawing and labelling plant and animal cells from memory, then check against the diagrams.
  • Then take the quiz. Aim for 8 out of 10 or better.
Check your understanding

Quiz

1.

Which is part of the cell theory?

2.

A microscope has a 10× eyepiece and a 10× objective. Total magnification?

3.

Which organelle releases energy from food?

4.

Which structure is found in plant cells but not animal cells?

5.

Diffusion is the movement of particles from…

6.

A plant cell in pure water becomes…

7.

Which is unicellular?

8.

Several tissues working together form…

9.

Antibiotics work against…

10.

Which technology can show the inside of a mitochondrion in fine detail?

For parents and teachers

Use this review to find gaps. If your child makes mistakes on:

  • cell theory, Hooke, Leeuwenhoek or viruses → revisit Cell Theory: What Every Living Thing Has in Common.
  • microscope parts, total magnification or estimating cell size → Using a Microscope.
  • mm ↔ µm, actual size from a photo, or electron microscopes → Seeing Smaller.
  • nucleus, membrane, cytoplasm, mitochondria, vacuoles → Inside an Animal Cell.
  • cell wall, chloroplasts, central vacuole, or plant vs animal comparisons → Plant Cells and How They Compare to Animal Cells.
  • direction or speed of diffusion → Diffusion.
  • cells swelling, shrinking or wilting in different solutions → Osmosis.
  • amoeba, paramecium, yeast, surface area to volume, bacteria doubling → Unicellular and Multicellular Organisms.
  • specialized cells, the four animal tissues, xylem and phloem → Specialized Cells and Tissues.
  • levels of organization, organs and systems working together → From Cells to Organisms.
  • cancer, UV, antibiotics, vaccines → Keeping Cells Healthy.
  • benefits, harms and perspectives on developments → Cell Biology Breakthroughs.

A great final check: ask your child to draw and label a plant cell and an animal cell from memory and explain each part's job out loud.