Whats in Your Cells? | 5th Grade Reading Comprehension Worksheet - Free Printable

The image contains a worksheet titled "What's in Your Cells?" from the "Crest Curriculum: Part 1 Life Science" series. The task involves answering questions based on the reading passage provided. Below, I will solve each question step by step and explain the solution.

---

Question 1:

> "Contrast a plant cell with an animal cell. How can you tell them apart?"

#### Solution:
Plant cells and animal cells are both eukaryotic cells, meaning they have a nucleus and membrane-bound organelles. However, there are key differences between them:

1. Cell Wall:
- Plant cells have a rigid cell wall made of cellulose, which provides structural support and protection.
- Animal cells do not have a cell wall; instead, they have a flexible cell membrane that defines their shape.

2. Chloroplasts:
- Plant cells contain chloroplasts, which are organelles responsible for photosynthesis (converting light energy into chemical energy).
- Animal cells do not have chloroplasts because they cannot perform photosynthesis.

3. Vacuoles:
- Plant cells typically have one large central vacuole that stores water, nutrients, and waste products.
- Animal cells may have smaller vacuoles or none at all.

4. Plastids:
- Plant cells contain various types of plastids (e.g., chloroplasts, chromoplasts), which are involved in storing pigments and other substances.
- Animal cells do not have plastids.

5. Shape:
- Plant cells are generally rectangular or box-like due to the presence of the cell wall.
- Animal cells are more irregular or round in shape because they rely on the flexibility of the cell membrane.

#### Answer:
- Plant cells have a cell wall, chloroplasts, and a large central vacuole, while animal cells lack these features.
- You can tell them apart by looking for the presence of a cell wall, chloroplasts, and the size and number of vacuoles.

---

Question 2:

> "List two types of organelles."

#### Solution:
Organelles are specialized structures within a cell that perform specific functions. Here are two examples:

1. Nucleus:
- The nucleus is the control center of the cell. It contains the cell's DNA and regulates gene expression.
- It is surrounded by a double membrane called the nuclear envelope.

2. Mitochondrion:
- Mitochondria are often referred to as the "powerhouses" of the cell because they produce energy in the form of ATP through cellular respiration.
- They have a double membrane and contain their own DNA.

#### Answer:
- Nucleus
- Mitochondrion

---

Question 3:

> "Predict what might happen if a cell lost its ability to perform cellular respiration."

#### Solution:
Cellular respiration is the process by which cells break down glucose (or other organic molecules) to produce energy in the form of ATP. If a cell lost its ability to perform cellular respiration:

1. Energy Deficit:
- The cell would no longer be able to generate sufficient ATP, which is essential for powering cellular activities such as movement, growth, and maintaining homeostasis.

2. Metabolic Shutdown:
- Without ATP, many cellular processes would cease, including protein synthesis, active transport across membranes, and muscle contraction.

3. Cell Death:
- Prolonged inability to perform cellular respiration would lead to the death of the cell. In multicellular organisms, this could result in tissue damage or organ failure.

4. Anaerobic Metabolism (if possible):
- Some cells might switch to anaerobic respiration (e.g., fermentation) as a temporary alternative, but this produces much less energy and generates waste products like lactic acid or ethanol.

#### Answer:
If a cell lost its ability to perform cellular respiration, it would experience an energy deficit, leading to the shutdown of essential cellular processes and ultimately resulting in cell death.

---

Question 4:

> "What are the processes in which materials move through a cell membrane?"

#### Solution:
Materials move across the cell membrane through several processes, depending on the nature of the substance and whether energy is required:

1. Diffusion:
- Passive movement of molecules from an area of high concentration to an area of low concentration.
- No energy is required.

2. Osmosis:
- A specific type of diffusion where water molecules move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.

3. Facilitated Diffusion:
- Passive movement of molecules across the membrane with the help of transport proteins (e.g., carrier proteins or channels).
- No energy is required.

4. Active Transport:
- Movement of molecules against their concentration gradient (from low to high concentration).
- Requires energy in the form of ATP.

5. Endocytosis:
- Process by which cells engulf external substances (e.g., food particles or molecules) by forming vesicles.
- Includes phagocytosis (solid particles) and pinocytosis (liquid droplets).

6. Exocytosis:
- Process by which cells expel substances (e.g., waste products or secretions) by fusing vesicles with the plasma membrane.

#### Answer:
The processes in which materials move through a cell membrane include:
- Diffusion
- Osmosis
- Facilitated diffusion
- Active transport
- Endocytosis
- Exocytosis

---

Question 5:

> "What is the control center of a cell?"

#### Solution:
The nucleus is the control center of a cell. It contains the cell's genetic material (DNA) and controls all cellular activities, including:

1. Gene Expression:
- The nucleus regulates which genes are turned on or off, determining which proteins are synthesized.

2. Replication:
- During cell division, the nucleus replicates its DNA to ensure that each daughter cell receives a complete set of genetic information.

3. Communication:
- The nucleus coordinates communication between different parts of the cell and responds to signals from the environment.

4. Structure:
- The nucleus is enclosed by a double membrane called the nuclear envelope, which has pores that allow selective passage of molecules.

#### Answer:
The control center of a cell is the nucleus.

---

Final Answers:

1. Plant cells have a cell wall, chloroplasts, and a large central vacuole, while animal cells lack these features. You can tell them apart by looking for the presence of a cell wall, chloroplasts, and the size and number of vacuoles.
2. Nucleus, Mitochondrion
3. If a cell lost its ability to perform cellular respiration, it would experience an energy deficit, leading to the shutdown of essential cellular processes and ultimately resulting in cell death.
4. Diffusion, Osmosis, Facilitated diffusion, Active transport, Endocytosis, Exocytosis
5. The control center of a cell is the nucleus.

---

Final Answer Box:
\boxed{
\begin{aligned}
1. & \text{ Plant cells have a cell wall, chloroplasts, and a large central vacuole, while animal cells lack these features.} \\
2. & \text{ Nucleus, Mitochondrion} \\
3. & \text{ If a cell lost its ability to perform cellular respiration, it would experience an energy deficit, leading to the shutdown of essential cellular processes and ultimately resulting in cell death.} \\
4. & \text{ Diffusion, Osmosis, Facilitated diffusion, Active transport, Endocytosis, Exocytosis} \\
5. & \text{ The control center of a cell is the nucleus.}
\end{aligned}
}