Biology worksheet focusing on animal tissues, including definitions, identification, and functions of epithelial tissue.

Certainly! Below is the completed SHS Biology I Laboratory Worksheet on Animal Tissues: Structure and Functions, with answers and explanations for each question.

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SHS BIOLOGY I LABORATORY WORKSHEET

Animal Tissues: Structure and Functions

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#### 1. Define tissue.
Answer:
A tissue is a group of similar cells that work together to perform a specific function in an organism.

Explanation:
Tissues are formed when cells with similar structures and functions unite to carry out specialized tasks, such as protection, support, contraction, or signaling.

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#### 2. Use the key choices to identify the major tissue types described below.
Key: connective, epithelium, muscular, nervous

| Description | Tissue Type |
|------------|-------------|
| 1. lines body cavities and covers the body's external surface | epithelium |
| 2. pumps blood, flushes urine out of the body, allows one to swing a bat | muscular |
| 3. transmits waves of excitation | nervous |
| 4. anchors and packages body organs | connective |
| 5. cells may absorb, protect, or form a filtering membrane | epithelium |
| 6. most involved in regulating body functions quickly | nervous |
| 7. major function is to contract | muscular |
| 8. the most durable tissue type | connective |
| 9. abundant nonliving extracellular matrix | connective |
| 10. forms nerves | nervous |

Explanation of Answers:
- Epithelium: Covers body surfaces and lines cavities; involved in absorption, protection, secretion, and filtration.
- Muscular: Responsible for movement (e.g., heart pumping, voluntary motion).
- Nervous: Conducts electrical impulses for communication and control.
- Connective: Supports, binds, and protects tissues; includes bone, blood, fat, etc., with large amounts of extracellular matrix.

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#### 3. On what bases are epithelial tissues classified?
Answer:
Epithelial tissues are classified based on:
- Number of cell layers: Simple (one layer) or stratified (multiple layers).
- Shape of the cells: Squamous (flat), cuboidal (cube-shaped), or columnar (tall and column-like).

Explanation:
This classification helps determine the function of the epithelium. For example:
- Simple squamous → thin, for diffusion (e.g., alveoli).
- Stratified squamous → protective (e.g., skin).
- Ciliated pseudostratified columnar → secretion and movement (e.g., respiratory tract).

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#### 4. How is the function of an epithelium reflected in its arrangement?
Answer:
The structure of epithelial tissue directly reflects its function:
- Simple epithelium (single layer): Allows rapid exchange (e.g., absorption in intestines, filtration in kidneys).
- Stratified epithelium (multiple layers): Provides protection against abrasion (e.g., skin, mouth lining).
- Ciliated epithelium: Moves mucus or fluids (e.g., in trachea).
- Glandular epithelium: Secretes substances (e.g., sweat glands, liver cells).

Explanation:
This principle follows the biological concept: "structure determines function." The shape, number of layers, and presence of cilia or microvilli all adapt the tissue to its role.

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✔ Final Notes:
This worksheet reinforces understanding of the four main tissue types and emphasizes how form follows function in biology—especially in epithelial tissues.

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