2A2 Levels of Biological Organization Flashcards
Learn about levels of biological organization: cells, tissues, organs, and systems.
What is tissue?
A group of specialized cells that perform the same function and have a similar structure.
What is the study of tissues commonly known as?
Histology
Involves the study of tissues, involving their preparation, analysis, and examination under a microscope.
What are the four basic tissues in an animal body?
- Epithelial tissue
- Connective tissue
- Muscular tissue
- Nervous tissue
Each tissue type has distinct structures and functions, for example, epithelial tissue covers surfaces, while nervous tissue transmits signals.
What is epithelial tissue comprised of?
Sheets of epithelial cells that are in contact with each other.
What are the functions of epithelial tissue in the body?
- Covering the external surfaces of the body.
- Lining the internal cavities.
- Forming and lining various organs and glands.
How are epithelial cells categorized based on their shape and layers?
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Shape:
- Simple squamous (single layer, flat cells)
- Cuboidal (cube-shaped)
- Columnar (taller than wide)
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Layers:
- Simple (one layer)
- Stratified (multiple layers)
What is connective tissue made up of?
A matrix comprised of cells and extracellular material.
The extracellular material, also known as the extracellular matrix, includes fibers like collagen and elastic fibers, and a ground substance that can be fluid, gel-like, or solid.
What are the two types of connective tissue?
- Dense connective tissue: thick, densely packed collagen fibers.
- Loose connective tissue: loose, irregularly arranged fibers.
What are the three types of muscle tissues in animals?
- Skeletal muscle (voluntary)
- Cardiac muscle (involuntary)
- Smooth muscle (involuntary)
What are the muscle fibers comprised of?
Two contractile protein filaments: actin and myosin.
These filaments interact to cause muscle contraction through a process called the sliding filament theory.
What type of control are smooth and cardiac muscle fibers under?
Involuntary control.
What are the two main parts of nervous tissue?
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
What are the two contractile protein filaments found in myofibrils?
- Actin
- Myosin
What are the two major tissues in plants?
- Meristematic tissue
- Permanent tissue
Meristematic tissue is involved in plant growth.
Permanent tissue includes differentiated cells that perform specific functions.
What are the two categories of permanent tissues in plants?
- Simple tissues
- Complex tissues
What are the three tissue systems in plant permanent tissue?
- Dermal tissue
- Ground tissue
- Vascular tissue
What is the function of phloem in plants?
Transport food in a process called translocation.
Phloem primarily transports sugars and other metabolic products downward from the leaves.
What is the function of xylem in plants?
Transports water in a process known as transpiration.
Xylem also transports mineral ions from the soil to the rest of the plant and provides structural support.
What is an organ system?
A collection of organs working together toward a common goal.
Organ systems include multiple organs, but organs may be involved in more than one organ system.
E.g. The digestive system.
What does the integumentary system include and what is its main function?
- Includes: skin, nails, and hair.
- Main function: Protect the body.
What are the main components and functions of the skeletal system?
- Components: bones, joints, and cartilage.
- Functions: Provides structure, support, and facilitates movement.
Bones also produce blood cells and store minerals like calcium and phosphorus.
What are the main components and functions of the circulatory system?
- Components: heart, blood vessels, and blood.
- Functions: Transport oxygen, nutrients, and remove waste.
The heart pumps blood through the blood vessels to the body.
What is the main function of the respiratory system?
To carry out gas exchange.
Air enters the lungs through the nose and mouth and travels to the alveoli for gas exchange.
What are the main components and function of the nervous system?
- Components: brain, spinal cord, and nerves.
- Function: Facilitates communication throughout the body.
The nervous system is divided into the central nervous system (CNS) and peripheral nervous system (PNS), with the CNS processing information and the PNS transmitting signals.
