Biology as the Study of Life

Biology

AS THE STUDY OF L IFE

SOME THINGS YOU NEED TO KNOW

Key Words

Cell

Basic structural and functional unit of living organisms

Prokaryotic vs. Eukaryotic Prokaryotes don’t have a real nucleus Eukaryotes have a nucleus with a double membrane

Plant vs. Animal Plant cells have a rigid cell wall and chloroplasts Animal cells have lysosomes

Regulation & Feed Back

Regulation The adaptation of form or

behavior of an organism to changed conditions.

Feedback A cause and effect chain

that loops back to the beginning.

Reproduction

The creation of a new organism from a “parent.”

The known methods of reproduction are broadly grouped into two main types: sexual and  asexual.

Enzymes

Catalyst in chemical reactions

The purpose of an enzyme in a cell is to allow the cell to carry out chemical reactions very quickly.

Emergent Property & Homeostasis

Emergent Property The emergence of

properties at each step of the levels of organization.

Homeostasis The tendency of a

system to stay under stable conditions.

Deoxyribonucleic Acid

Contains the genetic information used in the development and growth of an organism.

Made up of nucleotides which are formed from a 5-carbon sugar, a phosphate group, and one of 4 nitrogen bases (Adenine, Thymine, Guanine, and Cytosine.)

Metabolism

A set of chemical reactions that occur to

sustain life.

Catabolism A set of metabolic reactions that break down big,

complex molecules.Anabolism

A set of metabolic reactions that synthesize larger, more complex compounds.

Biodiversity

The degree of variety of organisms in a given specific area or location.

Biodiversity includes genetic variation within species and the variety of habitat types

Evolution

Any change between successive generations in the inherited traits of populations.

Open System & Stimuli

Open System A system that exchanges energy and materials with its

outside environment.Stimuli

A change that elicits or causes a response.

Taxonomy

The science of identifying, naming, and classifying organisms.

Uses Binomial Nomenclature Uses two names

Taxa:

WHAT MAKES L IFE , L IFE .

Characteristics of Life

Cellular and Organized

Single-cell organisms have everything they need to be self-sufficient.

In multicellular organisms, specialization increases until some cells do only certain things.

Reproduces

Reproduction is not essential for the survival of individual organisms, but must occur for a species to survive.

All living things reproduce in one of the following ways: Asexual reproduction - Producing offspring without

the use of gametes. Sexual reproduction - Producing offspring by the

joining of sex cells.

Genetic Code

Offspring resemble parents because they inherit their traits.

Nucleic acids is life’s manual, its blueprint to make an organism.

Grows and Develops

An organism develops when it matures.Cell division is the orderly formation of new

cells.Cell enlargement is the increase in size of a

cell. Cells grow to a certain size and then divide.An organism gets larger as the number of its

cells and size of its cells increases.

Energy

Living things take in energy and use it for maintenance and growth.

Responds

Living things will make changes in response to a stimulus in their environment.

A behavior is a complex set of responses.

Adapts and Evolves

Adaptations are traits giving an organism an advantage in a certain environment.

Variation of individuals is important for a healthy species.

Homeostasis

The ability of a system or living organism to adjust its  internal  environment  to maintain a stable  equilibrium.

“CHARRGED”

C – Cellular and OrganizedH – HomeostasisA – Adapts and EvolvesR – RespondsR – ReproducesG – Grows and DevelopsE – EnergyD – DNA, Genetic Code

THE MAIN POINTS

Themes of Biology

Cell

Cells are every organism’s basic units of structure and function. The two main types of cells are Prokaryotic cells (in Bacteria and Archaea) and Eukaryotic cells (in Protists, Plants, Fungi, and Animals).

Heritable Information

The continuity of life depends on the inheritance of biological information in the form of DNA molecules. This genetic information is encoded in the nucleotide sequences of the DNA.

Emergent Properties

The living world has a hierarchical organization, extending from molecules to the biosphere. With each step upward in level, system properties emerge as a result of interactions among components at the lower levels.

Regulation

Feedback mechanisms regulate biological systems. In some cases, the regulation maintains a relatively steady state for internal factors such as body temperature.

Interaction with the Environment

Organisms are open systems that exchange materials and energy with their surroundings. An organism’s environment includes other organisms as well as nonliving factors.

Energy and Life

All organisms must perform work, which requires energy. Energy flows from sunlight to producers to consumers.

Unity and Diversity

Biologists group the diversity of life into three domains: Bacteria, Archaea, and Eukarya. As diverse as life is, we can also find unity, such as a universal genetic code.

The more closely related two species are, the more characteristics they share.

Evolution

Evolution, biology’s core theme, explains both the unity and diversity of life. The Darwinian theory of natural selection accounts for adaptation of populations to their environment through the differential reproductive success of varying

individuals.

Structure and Function

Form and function are correlated at all levels of biological organization

Scientific Inquiry

The process of science includes observation- based discovery and the testing of explanations through hypothesis-based inquiry. Scientific credibility depends on the repeatability of observations and experiments.

“LUDEECRISS”

L – Life and EnergyU – Unity and DiversityD – DNAE – EvolutionE – Emergent PropertyC – CellR – RegulationI – Interacts with its EnvironmentS – Structure and FunctionS – Scientific Inquiry

MICRO TO MACRO

Levels of Organization

MoleculesCellsTissuesOrgansOrgan SystemsOrganismPopulation, same species, area, & timeCommunityEcosystemBiosphereCosmos