Bellwork 10/13

• Get out a piece of paper and put your name on it Big and Clearly.

• Draw your name into a picture of anything• Make sure your heading is on there.

– Name– Hour– Date– Subject

TEXTBOOK: From Bacteria

to Plants

Chapter One: Living Things

Section 1 “What is Life.” Pg. 16-23

MOO

PASS Strand: Diversity and Adaptations of Organisms

Objectives:By classifying

organisms, biologists consider details of internal and external structure.

OINK

What is Life?A.      The Characteristics of Living Things

• Organisms— a living thing.All living things have• a.        cellular organization• b.       Contain similar chemicals• c.        Use energy• d.       Grow and Develop• e.        Respond to their surroundings• f.         Reproduce

Cellular Organization

a.       All organisms are made of tiny building blocks called cells.

b.       Fit a million cells on the period at the end of this sentence.

c.       Unicellular or MulticellularManyfunctions

Contain Similar Chemicalsa. Water—most abundant

chemical in cells.b. Carbohydrates—energy sourcec.Proteins and lipids—building

materials of the cell. (like wood and bricks for houses)

d. Nucleic acids—genetic material. Directs the cells activities.

Use Energya. Cells use energy to grow and

repair injured parts.b. Cells for digestion need

energy to digest food particlesc. Blood cells need energy to

move chemicals to your body.

Grow and Develop

a.      Growth—becoming larger• b.       Development—change that

produces a more complex organism.

• Ex. Acorn turns into an oak tree

Respond to their surroundings

React to changes in their environmentb.  Stimulus (plural stimuli)—a change in

an organism’s surroundings that causes the organism to react.

i.      Ex. Changes in temperature, light, sound

c.       Response—an action or change in behavior. An organism reacts to a stimulus with a response.

Ex. When someone scares you (change of environment)

you may

scream, faint, run

( your response)

Reproduce• Reproduce—the ability to produce

offspring similar to the parents.

•   Robins produce Robins produce eggseggs

•   Sunflowers produce seeds that develop into sunflowers

•  Bacteria produce bacteria just like themselves.

Life Comes From Life

• New organisms arise from reproduction.

• Spontaneous generation—The mistaken idea that living things arise from nonliving sources.

Ex. Experiments of Redi and Pasteur pg. 20,

Francesco Redi

Disproving Spontaneous

Generation

• People used to believe that frogs sprouted from mud in ponds.

What is Spontaneous Generation?

• People used to believe that flies came from rotted meat.

What is Spontaneous Generation?

• This was a strongly held belief.

What is Spontaneous Generation?

•It took hundreds of years of experiments to convince people that it does not occur.

What is Spontaneous Generation?

• Redi was one scientist who worked to disprove this idea (in the mid-1600’s).

What is Spontaneous Generation?

What did Francesco Redi do?

• Francesco Redi did a controlled experiment to prove that spontaneous generation does not happen.

What did Francesco Redi do?

• His experiment focused on whether or not flies come from rotting meat.

Redi’s Controlled Experiment

Set-up A• Meat in jar• Jar open

• Maggots on meat

Set-up B• Meat in jar• Jar closed with

cloth• No Maggots in

jar

How was this a “Controlled Experiment”?

It was controlled because…

• He had only one manipulated variable – whether or not the meat was covered.

How is this a “Controlled Experiment”?

It was controlled because…

• When he got his results, he knew what caused them, because there was only one difference between the set-ups.

Redi’s Conclusion• Redi concluded that flies

had laid eggs on the rotting meat that wasn’t covered, and the eggs hatched into maggots. …

Redi’s Conclusion• So, the meat didn’t produce

the maggots (young flies), the adult flies produced the young flies by laying eggs on the uncovered meat.

What we can learn…• All living things come only from other living things.

• Spontaneous generation doesn’t happen.

The Needs of Living Things

              All living things must All living things must satisfy their satisfy their basicbasic needs needs for energy, water, living for energy, water, living space, space,

and stable and stable

internal conditions.internal conditions.

Energy • Heterotroph—Animals need food as their energy source, cannot make

their own food.•      Sun is energy source indirectly

b/c they either eat autotrophs and obtain their energy or consume other heterotrophs that eat autotrophs.

EnergyAutotroph—organism which can make its own food.

Water All living things need water to survive.

It can dissolve more chemicals than any other substance on earth. Helps by:

• Obtain chemicals from surroundings• Break down food• Grow• Move substances within their bodies• Reproduce

Living Space • All organisms need a space to

live. A place to get food and water, and to find shelter.

• Competition. • Plants only have so much

space. Compete for sunlight/ space. Roots compete for water and nutrients.

• Animals can move but share living spaces with others or compete for area.

Stable Internal Conditions• Organisms must be able to keep

the conditions inside their bodies constant.

• Homeostasis—keeping the internal conditions stable despite the changes in an organism’s surroundings.

Review

• What do all living things have in common?

Review

• What do all living things have in common?

• a.        cellular organization• b.       Contain similar chemicals• c.        Use energy• d.       Grow and Develop• e.        Respond to their surroundings• f.         Reproduce

Review

• What did Francisco Redi Prove?

Review

• What did Francisco Redi Prove?

• That living things do not come from non living things. (Flies do not come from meat)

Review

• What do all living things need?

Review

• What do all living things need?

• Water

• Living Space

• Energy

• Stable Internal Conditions