Chapter 1: The Scientific Study of Life Study Guide

The Five Characteristics of Life

Organization, Energy, Homeostasis, Reproduction, Evolution

Biological levels of organization

Atoms, molecules, compounds, organelles, cells, tissues, organs, organ system, multicellular organism, population, community, ecosystem, biosphere

Autotroph

Producers that cannot produce their own food. They get energy through photosynthesis.

Example of an autotroph

Green algae

Heterotrophs

Consumers that get their energy by feeding on other organisms. They cannot produce their own food.

Example of a heterotroph

Animals

Decomposers

These feed on dead, organic material to help recycle nutrients back into the environment.

Example of a decomposer

Fungi

Stimuli

Any detectable change in the environment

Internal stimuli

pH, oxygen, CO2, hormones, water, pain

External stimuli

Temperature, light, sound, smell, and pain

Asexual Reproduction

Any form of reproduction that does not involve the fusion of gametes (Ex. Mitosis)

Sexual Reproduction

A form of reproduction involving the fusion of gametes (Ex. Fertilization and conjugation)

Evolution

The result of change in the genetic makeup of a population

Adaptation

Long-term heritable aspects of behavior, morphology, physiology, biochemistry, and coloration that improve an organism’s chances of survival and reproduction.

Taxonomic Hierarchy

Organisms are classified into progressively smaller groups based on shared characteristics. (Taxonomy is the science of naming and classifying organisms)

Domain

1st Taxon level, largest and most inclusive

Kingdom

2nd Taxon level

Phylum

3rd Taxon level

Class

4th Taxon level

Order

5th Taxon level

Family

6th Taxon level

Genus

7th Taxon level

Species

8th Taxon level, most specific and least inclusive

Kingdom Eubacteria

oldest group of bacteria; organisms in this group are composed of prokaryotic cells (lack a true nucleus and membrane-bound organelles)

Kingdom Archaebacteria

prokaryotic cells; bacteria love extreme environments (too hot, too salty, too acidic for other organisms to survive in).

Kingdom Protista

organisms in this kingdom are composed of eukaryotic cells (possess a true nucleus and membrane-bound organelles); very diverse group of organisms.

Kingdom Fungi

composed of eukaryotic cells; excellent decomposers.

Kingdom Plantae

organisms are composed of eukaryotic cells. Organisms are autotrophic and photosynthetic; possess cells walls of cellulose

Kingdom Animalia

organisms are composed of eukaryotic cells. These organisms are heterotrophic; do not possess cell walls; not photosynthetic.

Biology

the scientific study of life and living organisms

Organism

Any living structure

Cells

Basic structural functional units of life

Homeostasis

The body’s ability to maintain relatively stable internal environment in the presence of changing conditions

Organelles

Complex, cytoplasmic structures with characteristic shapes, that provide one or more specific function

Population

A group of organisms of the same species

Species

Groups of potentially interbreeding natural populations that are reproductively isolated from other such groups

Community

Groups of organisms of the same species

Ecosystem

A community of living organisms that interact with their physical environment

Scientific Method

The step-by-step method of approaching a problem by creating a hypothesis and testing it through experiments to support or not support.

Observations

The first step in the SM: Data is collected based on your observations

Data must be _______

Unbiased/collected objectively

Questions

The second step in the SM: Ask why the event you observe is occurring

Hypothesis

The third step in the SM: An educated guess on why the event is occurring. It must be testable but is never proven wrong or right, just supported.

Prediction

The fourth step in the SM: Based on the hypothesis and uses an “if, then” statement.

Experiment

The firth step in the SM: Tests the hypothesis and prediction.

Experimental Group

This group will receive the independent variable

Control group

This group does NOT receive the independent variable; helps to validate the experimental results.

Control variable

Variables that are the same between the control group and the experimental group (Example: the pot the plant is potted in)

Independent variable

The variable given to the experimental group and is expected to give the result from the hypothesis. (Ex. The amount of light given to a plant)

Dependent Variable

Variables that changed in response to the IV (Ex. The height of plants changing after bending towards the light ← the IV)

Science

The process of finding solutions or understanding events in nature, using the Scientific Method.