Exam 1 Biology

Biology

the scientific study of life

science

a body of knowledge (data) about the natural world

scientific method

the practices that produce scientific knowledge

Scientific Method

Observation → record of information using senses or tools

Question → scientific inquiry designed to address a specific gap in knowledge

Hypothesis → testable explanation for a set of observations based on the available data and guided by inductive reasoning.

Prediction → a forecast that fallows logically from a hypothesis

Experiment → procedure carried out to support, refute, or validate a hypothesis

Results → outcome of an experiment

Conclusion → determination of whether the hypothesis should be supported or rejected

\

Falsifiable

must be possibility of a negative answer

Statistics

quantitative/numeric summary of data

Taxonomy

science of classifying living things

Nomenclature

assignment of scientific names to the various taxonomic categories and to individual organisms

Classification

orderly arrangement of organisms into a hierarchy

Taxonomic Hierarchy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species, Strains

“Do Keep Pond Clean or Frogs Get Sick”

Three Domains of Life

* Bacteria
* Archaea
* Eukarya

Null Hypothesis

negative statements proposing that no relationship exists between two factors

alternative hypothesis

impossible to prove that a hypothesis is absolutely and permanently true

experiment

procedure carried out to support, refute, or validate a hypothesis

variables

factors within an experiment

Independent Variable

factor that is manipulated

Dependent Variable

factor that is affected by the manipulation of the independent variable

Controlled experiment

all extraneous variables are held constant so that they can't influence the results

Control Group

group that remains unmanipulated

Treatment group

manipulated group within the experiment

Data

information that is generally quantitative

Peer Review

evaluation of work by one or more people with similar competencies as the producers of the work

Emergent properties

result from the arrangement and interaction of parts within a system

Systems biology

the exploratory of a biological system by analyzing the interactions among its parts

cell

smallest unit of life that can perform all activities required for life

Gene expression

process of converting information from a gene to its cellular product

Descriptive Observations

reporting data found in nature

Analytical Observations

looking for patterns in the data and addressing how or why they came to exist

Theory

\n explanation that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence

Fact

\n piece of information that is correct based on all current information

Law

basic principle, generalization, regularity or rule that holds true universally under particular conditions

Biological Levels of Organization

Molecules, Organelles, Cells, Tissues, Organs, Organisms, Populations, Communities, Ecosystems, Biosphere

Prokaryotic

Bacteria: single-celled, no true nucleus

Eukaryotic

have a true nucleus

Chromosomes

contain a cell’s genetic material in the form of DNA

Genes

units of inheritance that transmit information from parents to offspring

Evolution

change over time, change in allele frequencies in populations through generations

Characteristics shared by all living organisms and living systems

1. complex, ordered organization consisting of one or more cells
2. use and transformation of energy to perform work
3. sensitivity and responsiveness to the external environment
4. regulation and homeostasis
5. growth, development, and reproduction


1. evolutionary adaptation where traits in populations change over time

Where do humans fall on the 3 domains of life?

Eukarya

Scientific name

combination of the genus and species names

Element

a substance that cannot be broken down to other substances by chemical rxns

Homeostasis

a roughly constant internal environment

matter

anything that takes up space and has mass

compound

substance consisting of two or more elements in a fixed ratio

molecule

two or more atoms of an element chemically joined together

atom

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

neutron

no electrical charge

in middle

protons

positive charge

in middle

electrons

negative charge

outside rings

atomic mass

total mass of one atom

\# of ps + ns

atomic number

number of protons

radioactive

nucleus that breaks down spontaneously releasing tiny, high-speed particles that carry energy

isotope

two or more atomic forms of an element that differ in number of neutrons

valence shell

the outmost energy shell of an atom

valence electron

an electron that occupies the valence shell

valence

corresponds to the number of electrons required to complete the atom

electronegativity

atom’s attraction for the electrons of a covalent bond

ions

atoms or molecules that care charge as a result of gaining or losing electrons

cation

a positively charged ion

anion

a negatively charged ion

Chemical equilibrium

reached when the forward and reverse rxn rates are equal

solution

liquid consisting of a homogeneous mixture of two or more substances

Solvent

the dissolving agent in a solution

pH scale

represents conc of H+ bonds

Acids

lose H+ ions to an aqueous solution

Bases/Alkaline

accept H+ ions from an aqueous solution

Covalent

two atoms share electrons and are surrounded by an electron cloud (1)

Ionic bond

attraction between two ions with opposite electrical charge (2)

Hydrogen Bonds

bond molecules together forms slights +H atom and - atom in other (3)

Van Der Waals Bonds

occurs only when the atoms or molecules are very close together (4)

What percentage of natural elements are considered essential?

20-25%

What are the four most dominant essential elements in human bodies?

Oxygen (65%)

Carbon (18.5%)

Hydrogen (9.5%)

Nitrogen (3%)

What are the four water properties that help make life possible on Earth?

1. Cohesion → surface tension
2. Ability to moderate temp → regulates temperature
3. Low density as a solid → expansion upon freezing
4. good solvent

pH Scale

represents conc of H+ ions

\-log\[H+\]

Hydrocarbon

organic molecules consisting of only carbon and hydrogen

functional groups

Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, methyl

polymers

long strands of repeating units of small molecules called monomers

monomers

small molecules

bioinformatics

use of computer software and other \n tools to analyze the data

genomics

approach used to analyze large sets of \n genes or compare the genomes of different species

preteomics

Similar analysis of proteins

human genome project

Example of evolution of tolerance to toxic elements

sunflowers used to detoxify contaminated soils

Helpful uses of Radioactive isotopes

determining the age of fossils, medical imaging, cancer treatment, generating energy

Harmful uses of radioactive isotopes

can damage cells/DNA

Reactivity of an atom

presence of one or more unpaired electrons in the valence shell

Valence

pt

chemical bonds formed?

transferring or sharing of electrons

polar covalent bonds

if electronegative element is involved

nonpolar covalent bonds

if electronegative element is not involved

Electronegativity

all roads lead to fluorine

What are the keys to a molecule’s function in a cell?

size and shape

Magnification

lenses refract the light, so that the image is magnified

Resolution

Contrast

Organelles

specialized structures

cell

smallest unit of life that can function independently

Robert Hooke

1st person to observe cells in dead cork tissue

Electron Microscopy

more resolution, more magnification

Light Microscopy

less resolution, less magn., most subcellular structures are too small to be resolved by, can view while alive