BIO 120 Exam 1 WKU

organism

is a life form- a living entity made up of one or more cells.

1. Cells

2. Replication

3. Evolution

4. information

5. energy

5 Fundamental traits of cells

A theory

an explanation of an idea that is broad in scope and supported by a large body of evidence

Cell Theory

The theory that all organisms are made of cells and that all cells come from preexisting cells.

Hypothesis

A testable statement that explains a phenomenon or a set of observations.

experimental prediction

A measurable or observable result of an experiment based on a particular hypothesis. A correct prediction provides support for the hypothesis being tested.

chemical evolution

The theory that simple chemical compounds in the early atmosphere and ocean combined via chemical reactions to form larger, more complex substances, eventually leading to the origin of life and the start of biological evolution.

species

An evolutionarily independent population or group of populations. Generally distinct from other species in appearance, behavior, habitat, ecology, genetic characteristics, and so on.

evolution

The theory that all organisms on Earth are related by common ancestry and that they have changed over time, and continue to change, via natural selection and other processes.

population

A group of individuals of the same species living in the same geographic area at the same time.

natural selection

The process by which individuals with certain heritable traits tend to produce more surviving offspring than do individuals without those traits, often leading to a change in the genetic makeup of the population.

Heritable

Referring to traits that can be transmitted from one generation to the next.

speciation

The evolution of two or more distinct species from a single ancestral species.

Robert Hooke

First rudimentary microscope allowed him to visualize cork tissue to see chambers or “cells”

Anton van Leeuwenhoeks

His more powerful microscope could see microbes in pond water. He termed these “animalcules”

Robert Hooke, Anton van Leeuwenhoek

______ and ______ were the first to observe cells

James Watson and Francis Crick

proposed that DNA is a double-stranded helix

A, T, C, and G

What are the four building blocks of the double helix

DNA

Carries, or encodes, information needed for an organism’s growth and reproduction

RNA

is read to determine what building blocks to use to make a protein

Natural Selection

What is Charles Darwin famous for?

True

T/F: All cells come from preexisting cells

individuals

populations

Natural selection occurs in _____

Evolution occurs in _____

True

T/F: All organisms are made of cells

Fungi, animals

______ and _____ are more closely related to each other than either is to plants

Eukaryotic

______ cells have a membrane-bound nucleus

Prokaryotic

_______ cells do not have a membrane-bound nucleus

Sexual competition hypothesis

Why do Giraffe’s have long necks?

fitness

Ability of an organism to survive and reproduce in its environment

adaptation

Any heritable trait that increases the fitness of an individual with that trait, compared with individuals without that trait, in a particular environment.

chromosome

Gene-carrying structure consisting of a single long molecule of double-stranded DNA and associated proteins.

protein

A macromolecule consisting of one or more polypeptide chains composed of 50 or more amino acids linked together.

adenine triphosphate(ATP)

A molecule consisting of an adenine base, a sugar, and three phosphate groups that are linked together with covalent bonds that have high potential energy. Universally used by cells as a monomer for RNA synthesis and to store and transfer chemical energy.

tree of life

the phylogenetic tree that includes all organisms

phylogeny

The evolutionary history of a group of organisms.

phylogenetic tree

A branching diagram that depicts the evolutionary relationships among species or other taxa.

phylum

eukaryote

A member of the domain Eukarya; an organism whose cells contain a nucleus, numerous membrane-bound organelles, and an extensive cytoskeleton.

prokaryote

A member of the domain Bacteria or Archaea; a unicellular organism lacking a nucleus and containing relatively few organelles or cytoskeletal components.

taxonomy

The branch of biology concerned with the classification and naming of organisms.

scientific name

The unique, two-part name given to each species, with a genus name followed by a species name—as in Homo sapiens.

chemical evolution

The theory that simple chemical compounds in the early atmosphere and ocean combined via chemical reactions to form larger, more complex substances, eventually leading to the origin of life and the start of biological evolution.

Hydrogen, Carbon, Nitrogen, Oxygen

4 atoms that make up 96 percent of all matter found in organisms today.

protons

Positively charged particles

electrons

Negatively charged particles

element

A substance consisting of atoms with a specific number of protons.

atomic number

the number of protons in the nucleus of an atom

mass number

the total number of protons and neutrons in the nucleus of an atom

isotope

Any of several forms of an element that differ in the number of neutrons contained in their nuclei.

atomic weight

The average mass of an element that is based on the relative proportions of all its naturally occurring isotopes.

radioactive isotope

A version of an element that has an unstable nucleus, which will release radiation energy as it decays to a more stable form.

C, H, N, O, P, S (carbon, hydrogen, nitrogen, oxygen, and sulfur)

Make up over 99 percent of the atoms in your body

valence shell

outermost shell in an electron

valence electrons

An electron in the outermost electron shell, the valence shell of an atom.

chemical bonds

An attractive force binding two atoms together.

covalent bonds

A type of chemical bond in which two atoms share one or more pairs of electrons.

molecule

two or more atoms held together by covalent bonds

compounds

Any substance that consists of more than one element chemically bonded together.

electronegativity

A measure of the how strongly an atom pulls shared electrons toward itself in a bond.

non polar covalent bonds

A covalent bond in which electrons are equally shared between two atoms of the same or similar electronegativity.

polar covalent bonds

A covalent bond in which electrons are shared unequally between atoms differing in electronegativity, resulting in the more electronegative atom having a partial negative charge and the other atom having a partial positive charge.

ionic bonds

A chemical bond that is formed when an electron is completely transferred from one atom to another.

ion

An atom or a molecule that has lost or gained electrons and thus carries a full electric charge, either positive (cation) or negative (anion), respectively.

cation

A positively charged ion

anion

A negatively charged ion

oxygen & nitrogen

always form polar covalent bonds

water is a chemical solvent

What is the reason we are able to exist is because

water

the universal solvent

solvent

Any liquid in which one or more solids or gases can dissolve.

solution

A liquid containing one or more dissolved solids or gases in a homogeneous mixture.

solutes

Any substance that is dissolved in a liquid.

cohesion

The tendency of certain like molecules (e.g., water molecules) to cling together due to attractive forces.

hydrogen, covalent

it is easier to break a ______ bond than a ______ bond

True

T/F: covalent bonds only exist single molecules

adhesion

The tendency of certain dissimilar molecules to cling together due to attractive forces.

surface tension

The cohesive force that causes molecules at the surface of a liquid to stick together, thereby resisting deformation of the liquid's surface and minimizing its surface area.

specific heat

The amount of energy required to raise the temperature of 1 gram of a substance by 1°C; a measure of the capacity of a substance to absorb energy.

heat vaporization

The energy required to change 1 gram of a liquid into a gas.

chemical reaction

Any process in which substances combine or are broken down into other substances; involves the making and/or breaking of chemical bonds.

reactant

Any of the starting materials in a chemical reaction.

product

Any of the final materials formed in a chemical reaction.

acids

Any compound that gives up protons or accepts electrons during a chemical reaction or that releases hydrogen ions when dissolved in water.

bases

Any compound that acquires protons or gives up electrons during a chemical reaction or accepts hydrogen ions when dissolved in water.

buffers

A substance that, in solution, acts to minimize changes in the pH of that solution when acid or base is added.

endothermic

a chemical reaction that absorbs heat

exothermic

a chemical reaction that produced heat

potential energy

stored energy

chemical energy

The potential energy stored in chemical bonds between atoms.

organic compounds

A group of molecules that include at least one carbon atom; most have carbon-hydrogen bonds and carbon-carbon bonds.

amino acids

A small organic molecule with a central carbon atom bonded to an amino group (—NH3), a carboxyl group (—COOH), a hydrogen atom, and a side chain; are linked together to form proteins, they are referred to as residues.

organic

contains carbons

R-group

Part of an amino acid's core structure that varies from a single hydrogen atom to large structures containing carbon rings; a variable “side chain”

NH2

an amino function group

COOH

a carboxyl functional group

Function

Form follows _____

peptide bond

The ______ is formed between amino acids

Hydrophilic

Interacting readily with water; typically are polar compounds containing partially or fully charged atoms.

Hydrophobic

Not readily interacting with water; compounds are typically nonpolar molecules.

Hydrophilic R groups

groups that dissolve easily in water

Hydrophobic R groups

groups that tend not to dissolve easily in water