BIO100 Ch1

Biology

The study of living things

Key Characteristics of biology

• Order

• responds to stimuli

• Reproduction

• Growth and Development

• adaptation

• Homeostasis

• regulation

• Energy processing

Order

Living things are very organized, from smaller structures that make up the bigger structures.

Order of structures

Atoms > molecules > organelles > cells > tissues > organs > systems

An example of responding to stimuli

Sunflowers facing the sun, pupil dilation in response to light conditions, leaves drooping when touched

Reproduction

The ability to create offspring; single cell organisms clone themselves, multicellular organisms have reproductive cells that contain DNA and passed on to the offspring.

Adaptation

“Fit” in to their environment EX: Heat resistant Archaea, Neck length in girrafes

Growth and development

genes that determine growth and development in living organisms, Grow characteristics to the of their parents

Regulation

internal processes that keep the organism functional EX: transport of nutrients

Homeostasis

Maintaining ideal internal conditions even with extreme environmental changes

Positive feedbaack loop

when stimuli is increased in response to change, driving the system further away from its original state EX: Labor contractions, sneezing

Negative feedback loop

reversing or reducing the magnitude of a change in response to a change EX: sweating, shivering

Energy processing

source of energy to run metabolic systems, chemical energy from food, solar energy from the sun

Diversity

variability in living things due to evolution

Evolution

a process of gradual change over a long period of time where new species come from old species

Taxonomy

A system used to organize and classify organisms by how similar they are

Levels of Taxonomy in Order

• Domain

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

Phylogeny

The study of relationships between organisms, traces the evolutionary history of organism

Phylogenetic Tree

A diagram the shows the evolutionary relationships between organisms based on similarities and differences

Three domains of life

• Archaea: Unicellular Microorganism

• Bacteria: Unicellular microorganism that are extremophiles

• Eukarya: complex cellular organization, unicellular or multicellular

Nature of science

Knowledge about the natural world, concerns itself with material phenomena (matter and energy)

Scientific Method

Used to answer questions informed by science and reason using the following steps:

• Observation

• Question

• Testable, falsifiable Hypothesis

• Experimentation

• Analysis

• Reporting/summary

Independent Variable

the factor that is manipulated/changed in an experiment to observe its effects

Dependent Variable

the outcome/effect that is measured in response to changes in the independent variable

Consitancy

results are consistent when study is repeated under similar conditions

Representative Sample

A sample population that accurately reflects a large population, is diverse.

Control of variables

a other variables in an experiment that is minimized/controlled to minimize skewed results.

repeatability

a study that other researchers can replicate and can produce the same or similar results from.

Probability value (p value)

statistical measure of the results to see if they are significant or not

small p value

less than or equal to 0.05, significant effect or difference

large p value

more than 0.05, suggests there is no significance,