Cells & Systems

Unit 2

What Does it Mean to be Living?• What do all of these things have in common?

Characteristics and Functions of all Living Things

• All living things:– Need energy– Respond and adapt to their environment– Reproduce– Grow– Produce waste

* All organisms share these functions…

Levels of Organization

• Organisms have very specialized structures to carry out their various functions.

• When scientists study anything, they try to find similarities as a way of organizing their knowledge.

• Over many years of study, they have come to understand that most organisms have systems that perform certain functions to keep the organism alive.

Cells and Systems

• These functions are performed by systems in the organism.

• Systems are made up of organsEx: The heart is an organ of the circulatory system

• Organs are made up of tissuesEx: Muscle tissue make up the heart

• Cells make up all tissues

Functions and Systems• Plants and animals perform many of the same functions

– the systems that perform these functions may differ.Examples:• Gas exchange:

- Plant exchanges gas …- Animals exchange gas…

• Circulatory system:- Plants circulate…- Animals circulate…

• Digestive system:- Plants get there nutrients…- Animals get there nutrients…

Functions and Structures

1. Energy – Animals get energy from food and Plants from the sun (to help make their own food). 2. Environment – Plants need light to make food so they will bend towards the light. Raccoons feed at night/deer feed during the day. They both use their eyes under very different conditions. 3. Reproduction – living organisms reproduce so life will continue. A wolf has pups/a watermelon has seeds. They have different structures to carry out the same process. 4. Growth – Different organisms have different structures which allow them to grow. 5. Wastes – Animals and plants both need to excrete waste. (Ex: gas exchange)