Chapter 4: Section I: Pages What is Life?

The Characteristics of Living Things 6 Characteristics: 1.Made of Cells 2.Contain Similar chemicals 3.Use energy 4.Grow and develop 5.Respond to their Environment 6.Reproduce

Cellular Organization Cell –basic unit of structure and function –building blocks of life Think Legos = individual just a block, together you can create anything.

Cellular Organization Structure –How the cells come together to create something Think Blueprint for building a house.

Cellular Organization Function –The job or task that something does. Think, a hand’s function is to grab or hold things.

Cellular Organisms Unicellular –1 cell (Very Small) –Example: bacteria and ameba Multicellular –2 or more cells (Varies in size) –Example: people, muscles, nerves

The chemicals of life Carbohydrates –The cells main source of energy. Proteins and Lipids –The cells building materials Think wood and bricks of a house.

Energy Use Use energy to grow and repair injured parts. –Examples: Cells in stomach and intestines are used to digest food. Blood cells move chemicals throughout the body.

Growth and Development Growth = the process of becoming larger. Development = the process of change that occurs during and organisms life to produce a more complex organism. Think – acorn – seedling - tree

Response to Surroundings Stimulus (plural stimuli) –A change that causes an organism to react. External Stimuli – comes from outside the organism –Example: light, sound, and temperature of the environment Internal stimuli – comes from within the organism –Example: hunger and thirst

Response to Surroundings Response –How an organism reacts to a stimuli –Is a change in action or behavior Example: Stimulus = Friend jumps out and scares you Reaction = You jump and scream –Non-living things do not react to stimuli.

Reproduction Reproduce – produce offspring that are similar to the parents. –Example: Robins lay eggs, that develop into young robins that look like their parents.

Life Comes From Life Spontaneous Generation: –Idea that living things can arise (come from) nonliving sources Example: flies from rotting meat frogs from mud puddles

Dr. Francesco Redi

Dr. Louis Pasteur

The Needs of Living Things Living things must satisfy their basic needs. 1.Energy (food) 2.Water 3.Living Space 4.Stable Internal Conditions

1: Energy Autotrophs: makes own food –Auto = selftroph = feeder Example: plants –Solar Energy is directly related to food production.

1: Energy Heterotrophs: cannot make own food –Hetero = otherstroph = feeder Examples: animals, mushrooms, slime molds –Solar Energy is an indirect source of energy. Plants need the energy to survive, heterotrophs need the plants to survive.

2: Water ALL living things need water to survive. Most organisms can only live a couple of days without water.

2: Water Used for: –Obtaining chemicals from surroundings –Breaking down food –Growing –Moving substances within organism –Reproduction Fact: 92% of the liquid part of your blood is water.

3: Living Space Every organism needs a place to live. (Shelter) Limited resources cause competition. Plants are stationary and do not move locations to compete. Animals move around.

4: Stable internal Conditions Homeostasis: Stable inside despite changes in the surroundings Example: –Your body temperature stays at 98.6 degrees while the temperature outside is less than that. –A barnacle's ability to store water to maintain life outside the ocean water while in low tide.