Biology COLT Test

8 Characteristics of Life

1. Order

2. Sensitivty or response to stimuli

3. Reproduction

4. Adaptation

5. Growth and development

6. Regulation/homostasis

7. Energy processing

8. Evolutionary

Order

Highly organized, coordinated structures that consist of one or more cells

Sensitivty or response to stimuli

All organisms respond to diverse stimuli

Reproduction

• Single-celled organisms reproduce by duplicating DNA, and then dividing it equally as the cell prepares to divide to form 2 new cells

• Multicellurlar organisms often produce specialized reproductive cells-gametes (oocyte and sperm cells)

Adaptation

All living organisms exhibit a “fit” to their environment

Growth and development

Organisms grow/develop as a result of genes providing specific instructions that will direct cellular growth (increase in size/mass) and development (transformation as it goes through growth process)

Regulation/homostasis

Organisms aere able to maintain internal conditions within a narrow range almost constantly, despite environmental changes

Energy processing

All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy in food (photosynthesis). Others use chemical energy in molecules they take in as food (metabolism).

Evolutionary

The diversity of life on Earth is a result of mutations, or random changes in hereditary material over time. These mutations allow the possibility for organisms to adapt to a changing environment

Level of Organizations

(starts with organelles on test)

1. Atoms

2. Molecules

3. Macromolecules

4. Organelles

5. Cells

6. Tissues

7. Organs and organ systems

8. Organisms, populations, and communtities

9. Ecosystems

10. Biosphere

Phylogenetic Tree

• Constructed by microbiologist Carl Woese using data obtained from sequencing ribosomal RNA genes

• Shows seperation of living organisms into three domains: Bacteria, Archaea, and Eukarya

• (eu)Bacteria and archaea are prokaryotes, eukarya are eukaryotes

Prokaryotes

• Oldest cell type

• Small and simple

• Lack nucleus

• Lack organelles

• Single celled

• Bacteria

Eukaryotes

• Evolved from prokaryotes

• Larger and more complex, single or multicellular

• Contain a nucleus

• Contain organelles

Both Prokaryotes and Eukaryotes

Have DNA, Ribosomes, Cytoplasm, and Membrane

Eubacteria

• Standard bacteria

• No peptidoglycan in cell walls

• Cannot survive in extreme environments

• Bacteria and cyanobacteria

• Have a cell walls that protects the cell and determines its shape

Archaebacteria

• Peptidoglycan in cell walls

• Live in extreme envrionments

• DNA shows a closer evolutioanry relationship to eukaryotes

• Extremeophiles: Thermophiles, Halophiles, Methanogens

Methanogens

Live in oxygen free environment (thick mud, animal digestive tracks)

Halophiles

Live in salty environments

Thermophile

Live in hot environments (hot springs)

Both Archaebacteria and Eubacteria

• Are prokaryotes

• No nucleus

• Single celled

• Have ribosomes

• No membrane bound organelles

Identifying prokaryotes

• Gram positive bacteria have thick cell walls with large amounts of peptidoglycan (archaebacteria/extrem.)

• Gram negative bacteria have thinner cells walls inside an outer lipid layer

Areas of Biological Study

• Neurobiology—Biology of nervous system (neuroscience)

• Zoology—study of animals

• Botany—study of plants

• Molecularbiology—biological processes at the molecular level

• Biochemistry—biological processes at the chemical level

• Microbiology—study of microorganisms, single celled organisms

• Paleontology—use of fossils to study life’s history

Organelles

Small structures that exist within cells, contain aggregates of macrmolecules surrounded by membranes

Cell

Smallest fundamental unit of structure and function in lving organisms

Tissues

Groups of similar cells carrying out similar or related functions

Organs

Collections of tissues grouped together perfroming a common function. Present in animals/plants

Organ system

Higher level of organization that consists of functionally related organisms

Organisms

Indivdual living entities

Population

All the individuals of a species living within a specific area

Community

The sum of populations inhabitating a particular area

Ecosystem

Consists of all the living things in a particular area together with the abiotic, nonliving parts of that environment

Biosphere

The collections of all ecosystems, represents zone of life on Earth