Life on Planet Earth

cell

The basic structural and functional unit of all living organisms, smallest unit of life ex;muscle cell, nerve cell

organelle

a membrane enclosed structure with a specialized function within a eukaryotic cell such as mitochondria or chloroplasts.

molecule

a group of atoms bonded together by covalent(strong) bonds or hydrogen(weak) bonds

atom

the smallest unit of matter that retains the properties of an element

Dna is composed of…

Nucleotides

Biology

the scientific study of life

Fossils

imprints or remains of organisms that lived in the past (often found in sedimentary rock)

Biosphere

the entire portion of earth inhabited by life

Ecosystem

all of the organisms given area, along with the nonliving factors with which they interact

organ

a collection of tissues joined in a structural unit to serve a common function ex: heart,brain,liver

Peer Review

review of an article by experts before publication

organism

an individual living thing such as bacterium, fungus, plant or animal

tissue

a group of similar cells that together carry out a specific function ex: muscle tissue,nervous tissue

Prokaryotic cell

simpler and usually smaller characteristic of bacteria

Eukaryotic cell

subdivided by internal membranes into different functional compartments called organelles found in plants and animals.

Genome

the entire “book” of genetic instructions that an organism inherits

Taxanomy

the branch of biology that names and classifies species

Placebo

a fake treatment that mimics the experience of the experimental group (control group recieves)

Scientific Theory

science is a process

Parsimony analysis

a technique in which the simplest hypothesis is preferred

Sample Size

the number of experimental subjects

testable

supported by carefully designed experiments or non experimental studies

falsifiable

can be ruled out by data

Statistical Significance

a measure of confidence that the results obtained are “real” rather than due to random choice

Scientific Method

initial observations, study previous information, formulate hypothesis, hypothesis makes predictions, preform experiment, draw conclusions, publish results

Prospective study

looks forward in time to watch for outcomes

Retrospective studies

looking backward in time in relation to an outcome that is established at the start of the study

Epidemiology

the study of patterns of disease in population

Natural Selection

a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are individuals with other characteristics

population

a group of individuals of the same species living in the same place at the same time

evolutionary adaptation

a populations increase in the frequency of traits suited to the environment

Micro evolution

a change in genetic composition of a population over time

macroevolution

micro evolution occurring over very long spans of time (millions of years)

uniformitarianism

sculpted by gradual geological processes that continue today

Palentologists

scientist who study fossils

Biogeography

the study of geographic distribution species

Compartive anatomy

is the comparison of body structure between different species indicates evolution

Homology

the similarity in structures due to common ancestry

Analogy

the similarity in structures due to independent evolution

Vestigial structures

reminets of features that served important functions in an organisms ancestors

Allele

Each of two copies of a gene

Gene Pool

The total collection of alleles in a population at any one time

Genetic Drift

a change in the gene pool of a small population due to chance

Directional Selection

shifts the overall makeup of a population (=causes evolution) by selecting in favor of one extreme phenotype

Disruptive Selection

(=diversifying selection) can lead to a balance between two or more contrasting phenotypic forms in a population

Stabalizing selection

favors intermediate phenotypes (= prevents evolution), occurs in

relatively stable environments, and is the most common outcome.

anagenesis

change within a single species over time

cladogenesis

one species undergoes speciation which yields two species over time

speciation

the process in which one species splits in two

allopatric speciation

due to geographic isolation

sympatric speciation

without geographic isolation (but with ecological isolation)

Relative Dating

allows scientists to determine the age of the fossil from its position relative to layers of rocks or fossils of known age.

Absolute dating

technique used to date materials such as fossils found in igneous

rocks (relatively few fossils) or in sedimentary rock layers (most fossils) that are bracketed by igneous rock layers.