SSA Review 10 Organization & Development

Part 1 - Cell Theory Cell Theory - states that: 1 - all living organisms are composed of cells (single or multi-cellular), 2 - all cells come from pre-existing cells, and 3 - cells are the basic unit of life. http://www.youtube.com/watch?v=gFuEo2ccTPA

1 – All living things are composed of cells Unicellular – made of 1 cell only *Prokaryote (no nucleus)

1 – All living things are composed of cells Multi-cellular *Eukaryote (with a nucleus)

2 – All cells come from pre-existing cells *Asexual reproduction – single cell organism’s cell splits to form offspring *Sexual reproduction – parent cells (male and female) unite to create new offspring

2 – All cells come from pre-existing cells Mitosis- the process where the nucleus of a cell divides to create 2 new cells - each contains an identical copy of DNA

2 – All cells come from pre-existing cells Meiosis- the process where one cell divides into 4 different cells (each with different genetic material)

3 – Cells are the basic unit of life *In unicellular organisms, the cell is the organism. *In multi-cellular organisms, cells combine to form tissues, which combine to form organs, which combine to form organ systems, which combine to form the organism

Part 2 - Cell Structure & Function

Cell wall – Plant Cell ONLY *Provides extra support for the plant cell and gives it a shape *It's like taking a water balloon and putting it in a cardboard box (cell wall) Elodea Picture of Lily Parenchyma cell. The cell wall which provides a rigid structure is in green.

Cell membrane (Plant and Animal Cells) *Holds the cell organelles and fluid inside *Controls what materials enter and leave a cell. Animal Cell Plant Cell

Nucleus (Plant and Animal Cells) *Acts like the brain of the cell, directing activity, and making new cells *Contains the cell’s genetic material (DNA) including the chromosomes. Animal Cell Plant Cell

Mitochondria (Plant and Animal Cells) *Uses oxygen to transform the energy in food for the cell to use. *Sometimes called the “powerhouse” of the cell Animal Cell Plant Cell

Vacuoles (Plant and Animal Cells) *stores nutrients or waste. Animal Cell Plant Cell

Chloroplast- Plant Cell Only *Where photosynthesis takes place *They create sugars, and release oxygen into the air

Cytoplasm (Plant and Animal Cells) *Suspends the organelles inside the cell (jelly-like substance) Animal Cell Plant Cell

3. Organizational Structure

Levels of Organization in the Human Body Cells Tissues Organs Organ Systems Organism (Human body)

1. Cells – the smallest part of a living organism *function – tells parts of the body what they are and what to do Examples Blood Cells Skin Cells Nerve Cells

2. Tissue - A group of similar cells that work together to perform the same function. Types of Tissues

Eyes Brain Heart Stomach Lungs 3. Organ - Structures inside the body that perform a function (job) for the body. Eyes Brain Heart Stomach Lungs

Muscular System Skeletal System Digestive System Nervous System 4. Organ system - A group of organs that work together to perform a bodily function. Muscular System Skeletal System Digestive System Nervous System Circulatory System Excretory System Respiratory System Immune System Reproductive System

5. Organism – the entire person

*How do organ systems work together to make the body function properly?

*The muscles make the bones move, so the body is able to move

*The blood cells move food nutrients to all the cells throughout the body.

*The blood cells carry oxygen from the lungs to all cells in the body, and CO2 from the cells back to the lungs

*The nervous system/brain sends signals to the muscles that make them move the bones

Homeostasis *the ability of the body to maintain a stable internal environment despite changes in external conditions.  *all the body systems working together so the body functions with perfection