General Biology 2: Structure and Function

Study Notes

Structure and Function in Animals

The correlation between structure and function is one of biology's most fundamental concepts, and it is observed at each level in the structural hierarchy of an animal's body.

Hierarchy of Structural Organization

The hierarchy of structural organization in an animal's body consists of five levels: cellular, tissue, organ, organ system, and organism.
Each level builds upon the previous one to form a complex system.

Types of Tissues

There are four major categories of tissues in animals: epithelial, connective, muscle, and nervous tissues.
Each type of tissue has a specific structure and function that allows it to perform a particular role in the body.

Epithelial Tissue

Epithelial tissue occurs as sheets of closely packed cells that cover surfaces and line internal organs and cavities.
The structure of each type of epithelium fits its function, and it has several subtypes, including:
- Simple squamous epithelium (lining the air sacs of the lung)
- Simple cuboidal epithelium (forming a tube in the kidney)
- Simple columnar epithelium (lining the intestine)
- Stratified squamous epithelium (lining the esophagus)

Connective Tissue

Connective tissue is characterized by sparse cells that manufacture and secrete an extracellular matrix.
The matrix is composed of fibers embedded in a liquid, solid, or gel, and it binds and supports other tissues.
There are six major types of connective tissue, including:
- Loose connective tissue (under the skin)
- Adipose tissue (fat)
- Blood
- Fibrous connective tissue (forming a ligament)
- Cartilage (at the end of a bone)
- Bone

Muscle Tissue

Muscle tissue is responsible for movement and consists of three types:
- Skeletal muscle (responsible for voluntary body movements)
- Cardiac muscle (pumps blood)
- Smooth muscle (moves the walls of internal organs such as the stomach)

Nervous Tissue

Nervous tissue is responsible for transmitting nerve signals that help control body activities.
It is composed of branching neurons that form a communication network.

Organ Structure

Each organ is made of several tissues that cooperate to perform specific functions.
The structure of an organ is composed of different tissues, including epithelial, connective, muscle, and nervous tissues.

Description

Explore the fundamental concepts of biology, including the correlation between structure and function, and compare reproduction, development, and nutrition in plants and animals. This quiz covers the basics of biology, including the hierarchy of structures in the animal body.