Introduction to Cells Biology Worksheet for Age 14

Instructions

1. Complete each section in order. The questions begin with basic ideas and gradually become more challenging.
2. Use the word bank when provided. Write clearly and explain your thinking when asked.
3. For the cell-organelles table, study the example row, then complete the blank rows.
4. Complete the optional challenge if you finish the main activity.

Learning goals: By the end of this worksheet, you should be able to:

• Explain what a cell is and summarize cell theory.
• Identify important cell structures and describe their functions.
• Compare plant and animal cells.
• Connect cell structures to real-life examples.

1. What Is a Cell?

A cell is the smallest unit of a living thing that can carry out all the processes needed for life. Some organisms have only one cell, while others, such as humans and trees, are made of many cells.

A. Circle the best answer.

1. A cell is:

   • a. A type of tissue only found in animals
   • b. The smallest unit of life
   • c. A tiny organ inside the body
   • d. A nonliving particle

2. An organism made of one cell is called:

   • a. Multicellular
   • b. Unicellular
   • c. Microscopic tissue
   • d. Complex

3. Humans are:

   • a. Unicellular organisms
   • b. Multicellular organisms
   • c. Nonliving organisms
   • d. Organelles

B. Complete the statements.

Use these words: cells, living, scientists, basic

1. All __ things are made of one or more cells.
2. The cell is the __ unit of life.
3. New cells come from existing __.
4. __ use microscopes to study cells.

2. Cell Theory

Cell theory is a group of ideas that explains the importance of cells.

Write the three main statements of cell theory in your own words.

Hint: Think about where living things are made, what the cell is, and where new cells come from.

3. Organelles: The Cell's Working Parts

Organelles are specialized structures inside cells. Each organelle has a particular job, much like different workers in a school, business, or city.

Word bank: cell membrane, nucleus, cytoplasm, mitochondria, ribosomes, vacuole, chloroplast, cell wall

Example: The nucleus stores DNA and helps control the activities of the cell.

Word bank hint: You may use each word once. Some structures are found in plant cells, some in animal cells, and some in both.

4. Cell Structure Matching

Match each structure with its best description. Write the correct letter on the line.

1. Cell membrane _____
2. Mitochondria _____
3. Ribosomes _____
4. Chloroplasts _____
5. Vacuole _____
6. Cell wall _____

A. Use light energy to help plants make food

B. Controls what enters and leaves the cell

C. Makes proteins for the cell

D. Provides extra support and shape in plant cells

E. Stores water, food, or waste

F. Releases usable energy from food

5. Plant Cells and Animal Cells

A. Sort each structure into the correct group.

Write each structure in the correct column: nucleus, chloroplast, cell membrane, cell wall, mitochondria, large central vacuole, ribosomes

B. Complete the comparison.

1. Plant cells have a __ that gives extra support, but animal cells do not.
2. Plant cells contain __, which capture light energy.
3. Both plant and animal cells have a __ that controls what enters and leaves.
4. A plant cell usually has a large __ for storing water.

6. Cell City Activity

Imagine that a cell is organized like a city. Match each cell structure to the city feature that has a similar job.

Choose from these city features: power station, city border, recycling center, warehouse, factory

Cell structures to use: mitochondria, cell membrane, vacuole, ribosomes, lysosome

7. Apply Your Knowledge

Read the situation and answer in complete sentences.

A plant is placed in a dark room for several days. It receives water but very little light. Its leaves begin to turn pale, and the plant grows weak.

1. Which organelle is most directly affected by the lack of light?

   ---

2. Why does this organelle need light?

   ---

3. Which cell process is likely to slow down?

   ---

4. Predict what might happen if the plant remains in darkness for several weeks.

   ---

8. Microscopic Thinking

Cells are often too small to see without a microscope.

A. Choose the best answer.

1. Why are microscopes useful in biology?

   • a. They make cells grow larger.
   • b. They allow us to observe structures too small to see with our eyes.
   • c. They turn animal cells into plant cells.
   • d. They create new organisms.

2. If a microscope makes an object appear larger, it increases the object's:

   • a. Mass
   • b. Magnification
   • c. Temperature
   • d. Age

B. Observation prompt

If you could observe one type of cell under a microscope, what would you choose? Explain why.

I would observe a __ cell because

9. Optional Challenge: Cell Problems

Answer one or both questions.

1. A cell has a damaged cell membrane. Predict two problems this could cause.

   ---

   ---

2. A muscle cell needs a large amount of energy. Which organelle would you expect it to have many of? Explain your answer.

   ---

   ---

Answer Key

1. What Is a Cell?

A.

1. b. The smallest unit of life
2. b. Unicellular
3. b. Multicellular organisms

B.

1. living
2. basic
3. cells
4. scientists

2. Cell Theory

Accept answers with the following ideas:

1. All living things are made of one or more cells.
2. The cell is the basic unit of structure and function in living things.
3. All cells come from preexisting cells.

3. Organelles: The Cell's Working Parts

Possible completed table:

4. Cell Structure Matching

1. B
2. F
3. C
4. A
5. E
6. D

5. Plant Cells and Animal Cells

A.

B.

1. cell wall
2. chloroplasts
3. cell membrane
4. vacuole

6. Cell City Activity

Possible answers:

7. Apply Your Knowledge

1. Chloroplasts are most directly affected.
2. Chloroplasts need light energy to carry out photosynthesis and help the plant make food.
3. Photosynthesis is likely to slow down.
4. The plant may stop growing, become weaker, lose its green color, and eventually die because it cannot make enough food.

8. Microscopic Thinking

A.

1. b. They allow us to observe structures too small to see with our eyes.
2. b. Magnification

B.

Answers will vary. Responses should name a cell type and give a reasonable explanation.

9. Optional Challenge: Cell Problems

1. Possible answers: The cell might lose important materials, allow harmful substances to enter, lose water, or be unable to maintain a stable internal environment.
2. Muscle cells would likely have many mitochondria because they need large amounts of energy for movement and contraction.