Unit 1 Science

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Lesson 1: Introduction to Living Things

5 characteristics of all living things

Living Things are Made of Cells

cell: membrane covered structure that contains all of the materials necessary for life

Living Things Respond to Their Environment:

all living things have the ability to sense change and to respond to the change

stimulus: a change that affects the activity of an organism

Living Things Reproduce:

DNA: genetic material that controls the structure and function of cells

sexual reproduction: two parents produce offspring and it gets DNA from each parent

asexual: single parent produces offspring that is identical

binary fission= organism splits into two parts

budding= new organism grows on parents until it is ready to separate

Living Things Use Energy

Living Things Grow and Mature

What do living things need to survive?

water, air, food, and a place to live

cells are made of water and cell reactions require water

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Lesson 2: Theory of Evolution By Natural Selection

What did Darwin observe?

formed idea on how evolution could happen

evolution: process by which organisms change over time

he observed differences among species

What other ideas influenced Darwin?

organisms pass traits onto offspring

organisms acquire traits- Jean Baptiste Lamarck

earth changes over time

a struggle for survival exists

What are the four parts of natural selection?

-natural selection is the process by which organisms that inherit advantageous traits tend to reproduce more successfully than other organisms do

Overproduction

-when plants or animals reproduce, it usually makes more than the environment can support

Genetic Variation

-variations: naturally occurring differences

-mutation: change in genetic material

-greater genetic variation in a population increases the chance that some individuals will have traits that can help them survive environmental changes or diseases

-traits that enhance an individual's ability to reproduce will also increase the probability of survival of a species

Selection:

- individuals with a particular trait are more likely to survive long enough to reproduce. As a common result, the trait is "selected" for becoming more common in the next generation

Adaptation

- adaptation: an inherited trait that helps an organism survive and reproduce

- as natural selection continues, adaptations grow more common in populations over successive generations

-over time, the population becomes better adapted to the environment

How do species change over time?

- Over Generations, Adaptions Become More Common

-Genetic Differences Add Up

What happens to species as the environment changes?

- Adaptations Can Allow a Species to Survive

- Some Species May Become Extinct

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Lesson 3: Evidence of Evolution

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Lesson 4: The History of Life on Earth

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Lesson 5: Classification of Living Things