Educational worksheet on cell biology for students, covering cell organelles and processes.

Let’s go step by step to answer each question based on the passage.

---

Question 1: Contrast a plant cell with an animal cell. How can you tell them apart?

From the passage:
- Plant cells have chloroplasts, which are used for photosynthesis (making food from sunlight). Animal cells do NOT have chloroplasts.
- Both have mitochondria, nucleus, cytoplasm, and cell membrane — so those don’t help tell them apart.
- The key difference mentioned is chloroplasts — only in plant cells.

So, you can tell them apart by looking for chloroplasts. If they’re there → it’s a plant cell. If not → likely an animal cell.

*(Note: In real biology, plant cells also have cell walls and large vacuoles, but the passage doesn’t mention those — so we stick to what’s written.)*

---

Question 2: List two types of organelles.

The passage lists several organelles:
- Nucleus
- Mitochondria
- Chloroplasts
- Cytoplasm (though technically cytoplasm is the fluid, not an organelle — but the passage calls it one)
- Cell membrane (again, sometimes considered part of the cell structure, not an organelle — but passage includes it)

But clearly named as organelles in the text:
→ “Mitochondria” and “Chloroplasts” are explicitly called organelles.

Also: “Nucleus” is described as having its own membrane and holding DNA — definitely an organelle.

So safe answers: nucleus and mitochondria (or chloroplasts).

---

Question 3: Predict what might happen if a cell lost its ability to perform cellular respiration.

Passage says:
> Cells get energy through a process called cellular respiration... This process converts stored glucose into usable energy (ATP)... Without this energy, cells cannot grow, reproduce, or carry out their functions.

So if a cell can’t do cellular respiration → no ATP → no energy → cell can’t function → will die.

Prediction: The cell would stop working properly and eventually die because it wouldn’t have energy to do anything.

---

Question 4: What are the processes in which materials move through a cell membrane?

Passage says:
> Materials move in or out of a cell from a place of high concentration to one of low concentration. This is called diffusion. Diffusion allows substances like oxygen and carbon dioxide to pass through the cell membrane without using energy.

It also mentions:
> Osmosis is a special kind of diffusion that moves water across the membrane.

And:
> Active transport requires energy to move materials against the concentration gradient.

Wait — let me check again.

Actually, rereading carefully:

> “Materials move in or out of a cell from a place of high concentration to one of low concentration. This is called diffusion.”

Then later:

> “Osmosis is a special kind of diffusion...”

And then:

> “Active transport requires energy to move materials against the concentration gradient.”

BUT — the question asks: “What are the processes in which materials move through a cell membrane?”

The passage directly names:
- Diffusion
- Osmosis (as a type of diffusion)
- Active transport

However, note: the passage says osmosis is a *kind* of diffusion — so maybe list both?

But to be precise, the main processes mentioned for moving materials through the membrane are:
→ Diffusion (including osmosis for water)
→ Active transport

Since the question says “processes” (plural), and the passage describes these three concepts, we should include all that apply.

But wait — let’s quote exactly:

“Materials move in or out of a cell from a place of high concentration to one of low concentration. This is called diffusion.”

Then: “Osmosis is a special kind of diffusion...”

Then: “Active transport requires energy to move materials against the concentration gradient.”

So yes — three terms are introduced related to movement across membrane: diffusion, osmosis, active transport.

But since osmosis is a subtype of diffusion, perhaps the expected answer is just diffusion and active transport.

Looking at standard middle school level, they often teach:
- Passive transport (diffusion + osmosis)
- Active transport

But the passage separates them.

To match the passage exactly, I think safest is to say:

Processes mentioned: diffusion, osmosis, and active transport.

But let’s see how the question is phrased: “What are the processes...” — plural — so likely expecting more than one.

In many curricula, they accept “diffusion and active transport” as the two main categories.

Given the passage explicitly defines all three, I’ll go with:

→ Diffusion
→ Osmosis
→ Active transport

But wait — re-read the exact sentence:

> “Materials move in or out of a cell from a place of high concentration to one of low concentration. This is called diffusion.”

Then immediately after:

> “Osmosis is a special kind of diffusion that moves water across the membrane.”

Then:

> “Active transport requires energy to move materials against the concentration gradient.”

So technically, osmosis is under diffusion. But since it’s called out separately, and the question says “processes”, I think listing all three is acceptable.

However, to avoid overcomplicating, and since the passage groups osmosis under diffusion, perhaps the intended answer is:

Diffusion and active transport

But let’s look at the wording again: “the processes in which materials move through a cell membrane”

All three involve movement through the membrane.

I think best to follow the passage literally.

Final decision: Since the passage introduces diffusion, then specifies osmosis as a type, then introduces active transport as different — I will list:

→ Diffusion
→ Active transport

(Osmosis is included under diffusion per the passage.)

Alternatively, if the teacher expects osmosis listed separately, but since the passage says “osmosis is a special kind of diffusion”, it’s safer to group it.

Actually, let’s check common textbook approach — usually, they say:

Passive transport: diffusion, osmosis, facilitated diffusion
Active transport: requires energy

But here, only diffusion, osmosis, and active transport are mentioned.

Given that, and to be accurate to the passage, I’ll write:

The processes are diffusion (which includes osmosis for water) and active transport.

But for simplicity in answering, since the question likely expects named processes, and the passage names three distinct ideas, I'll go with:

Diffusion, osmosis, and active transport

Wait — no, let's think like a student reading this.

The passage says:

1. Diffusion — general movement from high to low concentration.
2. Osmosis — specifically for water, still diffusion.
3. Active transport — opposite direction, needs energy.

So for Q4, the answer should be: diffusion and active transport — because osmosis is a form of diffusion.

Yes, that makes sense.

Confirming with logic: if something moves via osmosis, it’s still moving via diffusion — just specified for water.

So final answer for Q4: diffusion and active transport

---

Question 5: What is the control center of a cell?

Passage says:

> All cells have a control center called a nucleus. The nucleus stores a special molecule called DNA...

Clear and direct: nucleus

---

Now, compiling final answers:

1. Plant cells have chloroplasts; animal cells do not. You can tell them apart by checking for chloroplasts.
2. Two organelles: nucleus and mitochondria (or chloroplasts).
3. If a cell couldn’t perform cellular respiration, it would run out of energy (ATP) and stop functioning — leading to death.
4. Processes: diffusion and active transport.
5. Control center: nucleus.

Let me double-check Q4 once more.

Passage excerpt:

> “Materials move in or out of a cell from a place of high concentration to one of low concentration. This is called diffusion.”

> “Osmosis is a special kind of diffusion that moves water across the membrane.”

> “Active transport requires energy to move materials against the concentration gradient.”

So when asked “what are the processes”, and given that osmosis is defined as a *type* of diffusion, the broad categories are diffusion (passive) and active transport.

In most educational contexts at this level, they expect:

→ Diffusion
→ Active transport

Sometimes they add osmosis separately, but since the passage subsumes it under diffusion, I’ll stick with two.

Actually, looking at the way the questions are structured, and since Q4 says “processes” plural, and the passage highlights three terms, perhaps include all.

But to be safe and accurate, I recall that in many standardized tests, they consider:

- Diffusion (for gases/small molecules)
- Osmosis (for water)
- Active transport (against gradient)

As separate processes.

Given that, and since the passage gives each its own definition, I will list all three.

Final decision for Q4: diffusion, osmosis, and active transport

Because even though osmosis is a type of diffusion, the passage treats it as a distinct concept worth naming.

Okay, locking in.

---

Final Answer:

1. Plant cells have chloroplasts, which animal cells lack. You can tell them apart by looking for chloroplasts.
2. Nucleus and mitochondria (or chloroplasts).
3. The cell would not produce energy (ATP), so it could not grow, reproduce, or function — it would die.
4. Diffusion, osmosis, and active transport.
5. Nucleus