Cells and Tissues Worksheet | Assignments Anatomy | Docsity - Free Printable

The image you've uploaded is a page from a biology textbook or workbook, specifically Chapter 3 titled "Cells and Tissues". It contains an introductory section on cells and a set of questions with blanks to be filled in. You’ve already filled in the answers, so I’ll now verify and explain each answer, ensuring accuracy and providing context for better understanding.

---

✔ Section: CELLS – Overview

#### 1–4. Name the four elements that make up the bulk of living matter.
- 1. Hydrogen
- 2. Carbon
- 3. Oxygen
- 4. Nitrogen

✔ Correct!
These four elements—hydrogen (H), carbon (C), oxygen (O), and nitrogen (N)—make up about 96% of the mass of living organisms. They are the primary building blocks of organic molecules like proteins, nucleic acids, carbohydrates, and lipids.

> 🔍 Why these?
> - Carbon forms the backbone of all organic molecules due to its ability to bond with many other atoms.
> - Hydrogen and Oxygen are key components of water and organic compounds.
> - Nitrogen is essential for amino acids and nucleic acids.

---

#### 5. Name the single most abundant material or substance in living matter.
- Answer: Oxygen

✘ Incorrect.
While oxygen is a major element, the most abundant *substance* (not just element) in living matter is water (H₂O).

✔ Correct Answer: Water

> 💡 Explanation:
> Water makes up approximately 60–70% of the human body and is the most abundant compound in living cells. It serves as a solvent, helps regulate temperature, and participates in metabolic reactions.

---

#### 6. Name the trace element most important for making bones hard.
- Answer: Calcium

✔ Correct!
Calcium (Ca²⁺) is the primary mineral responsible for giving bones their hardness and strength. It combines with phosphate to form hydroxyapatite, the mineral component of bone.

> 🧬 Bonus: Calcium also plays roles in muscle contraction, blood clotting, and nerve signaling.

---

#### 7. Name the element, found in small amounts in the body, that is needed to make hemoglobin for oxygen transport.
- Answer: Iron

✔ Correct!
Iron (Fe) is a critical component of hemoglobin, the protein in red blood cells that binds oxygen in the lungs and carries it to tissues.

> 🔬 Iron deficiency leads to anemia, which causes fatigue and reduced oxygen delivery.

---

#### 8–12. Name five functions common to all cells.
You provided:
- 8. Reproduction
- 9. Metabolism
- 10. Excretion
- 11. Growth
- 12. Responds to Stimuli

✔ All correct!

Let’s go over each:

| Function | Explanation |
|--------|-------------|
| Reproduction | Cells divide (via mitosis or meiosis) to produce new cells for growth, repair, and reproduction. |
| Metabolism | Cells carry out chemical reactions to obtain and use energy (e.g., cellular respiration). |
| Excretion | Cells remove waste products (like CO₂, urea) produced during metabolism. |
| Growth | Cells grow by increasing in size and synthesizing new organelles and macromolecules. |
| Responds to Stimuli | Cells react to changes in their environment (e.g., nerve cells respond to electrical signals). |

> These five are universal characteristics of life at the cellular level.

---

✔ Final Summary of Corrections & Confirmations

| Question | Your Answer | Correct? | Notes |
|--------|------------|---------|-------|
| 1–4 | H, C, O, N | ✔ Yes | Correct elements |
| 5 | Oxygen | ✘ No | Should be Water (most abundant *substance*) |
| 6 | Calcium | ✔ Yes | Correct |
| 7 | Iron | ✔ Yes | Correct |
| 8–12 | Reproduction, Metabolism, Excretion, Growth, Responds to Stimuli | ✔ Yes | All correct |

---

✔ Recommended Correction:

Change Question 5 from:
> Oxygen
to:
> Water

---

📘 Final Answer Key (Corrected):

1. Hydrogen
2. Carbon
3. Oxygen
4. Nitrogen
5. Water *(corrected)*
6. Calcium
7. Iron
8. Reproduction
9. Metabolism
10. Excretion
11. Growth
12. Responds to Stimuli

---

Let me know if you'd like this formatted as a printable worksheet or need help with the next section!