UNIT B: CELLS AND SYSTEMS

1.0: Living things share certain characteristics and have structures to perform functions

Living things: What do all living things have in common?

Characteristics of living things: Most scientists agree on 6 characteristics of living things (Organisms): Made of cells Need energy Grow and develop Respond to the environment Reproduce Have adaptations of their environment

1. The Cell The cell is the basic unit of life They are usually microscopic (very tiny!) All living things have cells (even things that were alive but are now dead like tree bark)

2. Energy: All organisms need energy. Energy is the ability to make things move or change Organisms get energy from the environment and different organisms get energy in different ways. Plants get energy from the sun to make their own food Animals get energy from hunting and the environment around them Nutrients are substances that provide the energy and materials that organisms need to grow, develop and reproduce

There are many chemical processes that happen within a cell Some produce energy while some use energy There must be a balance for an organism to survive An organism’s Metabolism is the life processes that take place within their cells (the use and production of energy)

3. Responding to the Environment A Stimulus is anything that causes a response in an organism EG: the heat that you feel when you put your hand too close to fire A Response is a reaction to a stimulus EG: pulling your hand away from the heat WHAT ARE SOME STIMULUS AND RESPONSES?

4. Growth and Development Growth can be seen in change of size or change in structure As some organisms grow, they change their body shape and this is called development

5. Reproduction All living things come from other living things. This process is called reproduction Reproduction is not necessary for an organism to survive, but it is necessary for the survival for each type of organism.

6. Adaptations An adaptation is a characteristic that allows an organism to live in its environment Can you think of some type of adaptations?

1.2 Structure and Form

Structure: Structure is a part of an organism that performs specific tasks Structures can be body parts or organs: Eg: heart, nose, stomach, brain, kidney, bones, muscles, skin

Function: A purpose or a task EG: Transporting oxygen, moving your bones, breaking down food, protecting your internal organs.

Different Structures for Similar Functions & Variations in Structure Organisms have developed different structures for doing similar functions Animals need to move to find food…but all animals move differently! How does a plant move to find food? Often similar organisms have different variation's in their structures Birds with different beaks, snakes with different hides.

1.3 Organs and Organ Systems

Terms: Organ: a group of tissues that work together to perform a specific function Organ system: a group of organs that work together to perform a certain task, such as digestion or breathing.

Circulatory System

Respiratory System

Nervous System

Excretory System

Skeletal system

Muscular System

Integumentary System