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Keystones Flashcards

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1
Q

science

A

organized way of gathering and analyzing evidence about the natural world

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2
Q

observations

A

the act of noticing and describing events or processes in a careful, orderly way

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3
Q

inference

A

logical interpretation based on what scientists already know

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4
Q

hypothesis

A

a scientific explanation for a set of observations that can be tested in ways that support or reject it

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5
Q

controlled experiment

A

an experiment that keeps track of various factors or variables that can change

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6
Q

independent variable

A

the variable that is deliberately changed

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7
Q

dependent variable

A

the variable that is observed and that changes in response to the independent variable

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8
Q

control group

A

a group exposed to the same conditions as the experimental group except for one independent variable

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9
Q

data

A

detailed records of experimental observations (gathering information)

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10
Q

theory

A

well tested explanation that unifies a broad range observations and hypothesis, and enables scientists to make accurate predictions about new situations

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11
Q

bias

A

a particular preference or point of view that is personal, rather than scientific

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12
Q

biology

A

the study of life

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13
Q

DNA

A

the complex information organisms need to live, grow, and reproduce in a genetic code written in a molecule

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14
Q

stimulus

A

a signal to which an organism responds

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15
Q

sexual reproduction

A

when cells form two parents unite to form the first cell of a new organism

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16
Q

asexual reproduction

A

when a single organism produces offspring identical to itself

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17
Q

homeostasis

A

relatively constant internal physical and chemical conditions that organisms maintain

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18
Q

metabolism

A

the combination of chemical reactions through which an organism builds up or breaks down materials

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19
Q

biosphere

A

part of earth in which life exists in luring land, water and air or atmosphere

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20
Q

atom

A

the basic unit of matter

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21
Q

nucleus

A

the center of an atom, where the protons and neutrons…

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22
Q

electron

A

a negatively charged particle

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23
Q

element

A

a pure substance that consists entirely of one type of atom

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24
Q

isotope

A

atoms of the same element that differ in the number of neutrons they contain

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25
Q

compound

A

a substance formed by the chemical combination of two or more elements in definite proportions

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26
Q

ionic bond

A

one or more electrons are transferred from one atom to another

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27
Q

ions

A

positively and negatively charged atoms

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28
Q

covalent bonds

A

moving electrons travel about the nuclei of both atoms

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29
Q

molecule

A

the smallest unit of most compounds

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30
Q

van der Waals forces

A

intermolecular forces of attraction

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31
Q

hydrogen bond

A

attraction between a hydrogen atom with a partical positive charge and another atom with a partical negative charge

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32
Q

cohesion

A

an attraction between molecules of the same substance

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33
Q

adhesion

A

an attraction between molecules of different substances

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34
Q

mixture

A

a material composed of two or more elements or compounds that are physically mixed together but not chemically combined

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35
Q

solution

A

type of mixture in which all the components are evenly distributed

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36
Q

solute

A

substance that is dissolved

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37
Q

suspensions

A

mixtures of water and nondissolved material

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38
Q

pH scale

A

scale with values from O-14, used to measure the concentration of H+ ions in a solution

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39
Q

acid

A

any compound that forms H+ ions in a solution

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40
Q

base

A

a compound that produces hydroxide ions in a solution

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41
Q

buffers

A

weak acids or bases that can react with strong acids or based to prevent sharp, sudden changes in pH

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42
Q

monomers

A

small chemical unit that makes up a polymer

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43
Q

polymer

A

molecules composed of many monomers; makes up macromolecules

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44
Q

carbohydrates

A

compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1:2:1

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45
Q

monosacchoricles

A

simple sugar molecules

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46
Q

lipids

A

a large and varied group of biological molecules that are generally not soluble in water

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47
Q

nucleic acids

A

macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus; polymers assembled from nucleotides

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48
Q

nucleotides

A

subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

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49
Q

proteins

A

macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen

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50
Q

amino acids

A

compounds with an amino group one end a carboxyl group on the other end

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51
Q

chemical reaction

A

a process that changes, or transforms, one set of chemical into another

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52
Q

reactants

A

the elements of compounds that enter into a chemical reaction

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53
Q

products

A

the elements of compounds produced by a chemical reaction

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54
Q

activation energy

A

the energy needed to get a reaction started

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55
Q

catalyst

A

a substance that speeds up the rate of a chemical reaction

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56
Q

enzymes

A

proteins that act as biological catalysts (speed up chemical reactions that take place in cells)

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57
Q

cells

A

the basic unit of life

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58
Q

cell theory

A

a fundamental concept of biology

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59
Q

cell membrane

A

thin flexible barrier that surrounds all cells, regulates what goes in and out

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60
Q

nucleus

A

a large membrane enclosed structure that contains genetic material in the form of DNA; controls many of the cell’s activities

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61
Q

eukaryotes

A

cells that enclose their DNA in nuclei

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62
Q

prokaryotes

A

cells that do not enclose DNA in nuclei

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63
Q

cytoplasm

A

the portion of the cell outside the nucleus

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64
Q

organelles

A

specialized structure that performs important cellular functions within a cell

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65
Q

vacuoles

A

large, saclike, membrane-enclosed structures that store materials like water, salts, proteins, and carbohydrates

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66
Q

lysosomes

A

small organelles filled with enzymes

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67
Q

cytoskeleton

A

a network of protein filaments in a eukaryotic cell that gives the cell it’s shape and internal organization and is involved in movement

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68
Q

centrioles

A

structures in an animal cell that helps to organize cell division

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69
Q

ribosomes

A

small particles of RNA and protein found throughout the cytoplasm in all cells

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70
Q

endoplasmic reticulum

A

internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled

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71
Q

Golgi apparatus

A

organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell

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72
Q

chloroplasts

A

the biological equivalents of solar power plants that capture the energy from sunlight and convert it into food that contains chemical energy in a process called photosynthesis

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73
Q

mitochondria

A

the power house of the cell; converts the chemical energy stored in food into compounds that are more convenient for the cell to use

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74
Q

cell wall

A

a strong supporting layer around the membrane

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75
Q

lipid bilayer

A

a double layered sheet that gives cell membranes a flexible structure that forms a strong barrier between the cell and its surroundings

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76
Q

selectively permeable

A

property of biological membranes that allows some substances to pass across it while others cannot

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77
Q

diffusion

A

the process by which particles move from an area of high concentration to an area of lower concentration

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78
Q

facilitated diffusion

A

the process in which molecules that cannot directly diffuse across the membrane pass through special protein channels

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79
Q

aquaporins

A

water channel proteins that allow water to pass right through them

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80
Q

osmosis

A

the diffusion of water through a selectively permeable membrane

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81
Q

isotonic

A

when the concentration of two solutions is the same

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82
Q

hypotonic

A

when comparing two solutions, the solution with the lesser concentration of solutes

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83
Q

osmotic pressure

A

the net movement of water out of or into a cell produces a force

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84
Q

tissue

A

a group of similar cells that performs a particular function

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85
Q

organ

A

group of tissues that work together to preform closely related functions

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86
Q

organ system

A

a group of organs that work together to preform a specific function

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87
Q

receptor

A

on or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone

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88
Q

hypertonic

A

when comparing two solutions, the solution with the greater concentration of solutes

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89
Q

adenosine triphosphate

A

(ATP) compound used by cells to store and release energy

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90
Q

heterotrophs

A

organisms that obtain food by consuming other living things

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91
Q

autotrophs

A

organisms that make their own food

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92
Q

photosynthesis

A

the process by which autotrophs use the energy of sunlight to produce high-energy carbohydrates -sugars and starches- that can be used as food

93
Q

pigment

A

light absorbing molecule used by plants to gather the sun’s energy

94
Q

chlorophyll

A

the plants’ principle pigment

95
Q

thykaloid

A

saclike photosynthetic membranes found in chloroplasts

96
Q

stroma

A

fluid portion of the chloroplast, outside the thykaloid

97
Q

NADP+

A

carrier molecule that transfers high-energy electrons from chlorophyll to other molecules

98
Q

light-dependent reactions

A

set of reactions in photosynthesis that use energy from light to produce ATP and NADPH

99
Q

light-independent reactions

A

set of reactions in photosynthesis that do not require light; energy from ATP and NADPH is used to build high-energy compounds such as sugar

100
Q

photosystems

A

clusters of chlorophyll and proteins found in thylakoids

101
Q

electron transport chain

A

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

102
Q

ATP synthase

A

cluster of proteins that span the cell membrane and allow hydrogen ions (H+) to pass through it

103
Q

Calvin cycle

A

light-independent reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugar

104
Q

calorie

A

the amount of energy needed to raise the temperature of 1 gram of water 1 degree celsius

105
Q

cellular respiration

A

the process that releases energy from food in the presence of oxygen

106
Q

aerobic

A

pathways of cellular respiration that requires oxygen

107
Q

anaerobic

A

pathways of cellular respiration that does not directly require oxygen, nor does it rely on an oxygen-requiring electron

108
Q

glycolysis

A

the first set of reactions in cellular respiration; during glycolysis, one molecule of glucose, a 6-carbon compound, is transformed into 2 molecules of pyruvic acid, a 3-carbon compound; literally means “sugar breaking”

109
Q

NAD+

A

an electron carrier; nicotinamide adenine dinucleotide; accepts a pair of high-energy electrons and becomes NADP

110
Q

Krebs Cycle

A

the second stage of cellular respiration; pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

111
Q

matrix

A

the innermost compartment of the mitochondrion and the site of the Krebs cycle reactions

112
Q

fermentation

A

the combined process of the pathway where oxygen is not present and glycolysis is followed by a pathway that make it possible to continue to produce ATP, and glycolysis; in the absence of oxygen, fermentation releases energy from food molecules by producing ATP

113
Q

cell division

A

the process by which a cell divides into two new daughter cells

114
Q

asexual reproduction

A

process of reproduction involving a single parent that results in offspring that are genetically identical to the parent

115
Q

sexual reproduction

A

type of reproduction in which cells from two parents unite to form the first cell of a new organism

116
Q

chromosome

A

threadlike structures of DNA and protein that contains genetic information; in eukaryotes, chromosomes are in the nucleus; in prokaryotes, chromosomes are in the cytoplasm

117
Q

chromatin

A

substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

118
Q

cell cycle

A

series of events in which a cell grows, prepares for division, and divides to form two daughter cells

119
Q

interphase

A

period of the cell cycle between cell divisions

120
Q

mitosis

A

part of eukaryotic cell division during which the cell nucleus divides

121
Q

cytokinesis

A

division of the cytoplasm to form two selects daughter cells

122
Q

prophase

A

first and longest phase of mitosis in which the genetic material inside the nucleus condenses and the chromosomes become visible

123
Q

centromere

A

region of a chromosome where the two sister chromatids attach

124
Q

chromatid

A

one of two identical “sister” parts of a duplicated chromosome

125
Q

centriole

A

structure in an animal cell that helps to organize cell division

126
Q

metaphase

A

phase of mitosis in which the chromosomes line up across the center of the cell

127
Q

anaphase

A

phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

128
Q

telophase

A

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin

129
Q

cyclin

A

one of a family of proteins that regulates the cell cycle in eukaryotic cells

130
Q

growth factor

A

on of a group of external regulatory proteins that stimulate the growth and division of cells

131
Q

apoptosis

A

process of programmed cell death

132
Q

cancer

A

disorder in which some of the body’s cells lose the ability to control growth

133
Q

tumor

A

mass of rapidly dividing cells that can damage surrounding tissue

134
Q

embryo

A

developing stage of a multicellular organism

135
Q

differentiation

A

process in which cells become specialized in structure and function

136
Q

totipotent

A

cells that are able to develop into any type of cell found in the body (including the cells tat make up the cells that make up the extra embryonic membranes and placenta)

137
Q

blastocyst

A

stage of early development in mammals that consists of a hollow ball of cells

138
Q

pluripotent

A

cells that are capable of developing into most, but not all, of the body’s cell types

139
Q

multipotent

A

cells with limited potential to develop into many types of differentiated cells

140
Q

stem cells

A

unspecialized cell that can give rise to one or more types of specialized cells

141
Q

genetics

A

scientific study of heredity

142
Q

fertilization

A

process in sexual reproduction in which male and female reproductive cells join to form a new cell

143
Q

trait

A

specific characteristics of an individual

144
Q

hybrid

A

offspring of crosses between parents with different traits

145
Q

gene

A

sequence of DNA that codes for a protein and thus determines a trait

146
Q

allele

A

one of a number of different forms of a gene

147
Q

principal of dominance

A

Mendel’s 2nd conclusion, which states that some alleles are dominant and others are recessive

148
Q

segregation

A

separation of alleles during gamete formation

149
Q

gamete

A

sex cell

150
Q

probability

A

likelyhood that a particular event will occur

151
Q

homozygous

A

having two identical alleles for a particular gene

152
Q

heterozygous

A

having two different alleles for a particular gene

153
Q

phenotype

A

physical characteristics of an organism

154
Q

genotype

A

genetic makeup of an organism

155
Q

punnet square

A

diagram that can be used to predict the genotype and phenotype combinations of a genetic cross

156
Q

independent assortment

A

one of Mendel’s principals that states genes for different traits can segregate independently during the formation of gametes

157
Q

imcomplete dominance

A

situation in which one allele is not completely dominant over another allele

158
Q

codominance

A

situation in which the phenotype produced by both alleles are completely expressed

159
Q

multiple alleles

A

a gene that has more than one allele

160
Q

polygenic trait

A

trait controlled by two or more genes

161
Q

homologous

A

term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent

162
Q

diploid

A

term used to refer to a cell that contains two sets of homologous chromosomes

163
Q

haploid

A

term used to refer to a cell that contains only a simple set of genes

164
Q

meiosis

A

process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

165
Q

tetrad

A

structure containing four chromatids that forms during meiosis

166
Q

crossing over

A

process in which homologous chromosomes exchange portions of their chromatids during meiosis

167
Q

zygote

A

fertilized egg

168
Q

transformation

A

process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria

169
Q

bacteriophage

A

kind of virus that infects bacteria

170
Q

base pairing

A

principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

171
Q

replication

A

process of copying DNA prior to cell division

172
Q

DNA polymerase

A

principal enzyme involved in DNA replication

173
Q

telomere

A

repetitive DNA at the end of a eukaryotic chromosome

174
Q

RNA

A

nucleic acid that consists of a long chain of nucleotides

175
Q

messenger RNA

A

type of RNA that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

176
Q

ribosomal RNA

A

type of RNA that combines with proteins to form ribosomes

177
Q

transfer RNA

A

type of RNA that carries each amino acid to a ribosome during protein synthesis

178
Q

transcription

A

synthesis of an RNA molecule from a DNA template

179
Q

RNA polymerase

A

enzyme that links together the growing chain of RNA nucleotides during transcription using a DNA strand as a template

180
Q

promoter

A

specific region of a gene where RNA polymerase can bind and begin transcription

181
Q

intron

A

sequence of DNA that is not involved in coding for a protein

182
Q

exon

A

expressed sequence of DNA, codes for a protein

183
Q

polypeptide

A

long chain of amino acids that makes proteins

184
Q

genetic code

A

collection of condons of mRNA, each of which directs the incorporation of a particular amino acid to be incorporated into a protein

185
Q

codon

A

group of three nucleotide bases in mRNA that specify a particular amino acid to be incorporated into a protein

186
Q

translation

A

process by which the sequence of bases of an mRNA is converted into the sequence of amino acids of a protein

187
Q

anticodon

A

group of three bases in a tRNA molecule that are complementary to the three bases of a codon of mRNA

188
Q

gene expression

A

process by which a gene produces its product and the product carries out its function

189
Q

mutation

A

change in the genetic material of a cell

190
Q

point mutation

A

gene mutation in which a single base pair in DNA has been changed

191
Q

frameshift mutation

A

mutation that shifts the “reading frame” of the genetic message by inserting or deleting a nucleotide

192
Q

mutagen

A

chemical or physical agents in the environment that interact with DNA and may cause a mutation

193
Q

polyploidy

A

condition in which an organism has extra sets of chromosomes

194
Q

operon

A

in prokaryotes, a group of adjacent genes that share a common operator and promoter and are transcribed into a single mRNA

195
Q

operator

A

short DNA region, adjacent to the promoter of a prokaryotic operon, that binds repressor proteins responsible for controlling the rate of transcription of the operon

196
Q

RNA interference

A

introduction of double stranded RNA into a cell to inhabit gene expression

197
Q

differentiation

A

process in which cells become specialized in structure and function

198
Q

homeotic gene

A

a class of regulatory genes that determine the identity of body parts and regions in an animal embryo. Mutations in these genes can transform one body part into another

199
Q

homeobox gene

A

the homeobox is a DNA sequence of approximately 130 base pairs, found in many homeotic genes that regulate development. Genes containing this sequence are known as homeobox genes, and they code for transcription factors, proteins that bind to DNA, and they also regulate the expression of other genes

200
Q

Hox gene

A

a group of homeotic genes clustered together that determine the head to tail identity of body parts in animals. All hox genes contain the homeobox DNA sequence

201
Q

evolution

A

change over time; the process by which modern organisms have descended from ancient organisms

202
Q

fossils

A

preserved remains or traces of ancient organisms

203
Q

artificial selection

A

selective breeding of plants and animals to promote the occurrence of desirable traits in offspring

204
Q

adaptation

A

heritable characteristics that increases an organism’s ability to survive and reproduce in an environment

205
Q

fitness

A

how well an organism can survive and reproduce in its environment

206
Q

natural selection

A

process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest

207
Q

biogeography

A

the study of past and present distribution of organisms

208
Q

homologous structures

A

structures that are similar in different species of common ancestry

209
Q

analogous structures

A

body parts that share a common function; but not structure

210
Q

vestigial structure

A

structure that is inherited from ancestors but has lost much of all of its original function

211
Q

extinct

A

term used to refer to a species that has no living members

212
Q

paleontologist

A

scientist who studies fossils

213
Q

relative dating

A

method of determining the age of a fossil by comparing its placement with that of fossils in other rock layers

214
Q

index fossil

A

distinctive fossil that is used to compare the relative ages of fossils

215
Q

radiometric dating

A

method for determining the age of a sample from the amount of a radioactive isotope to the nonradioactive isotope of the same element in a sample

216
Q

half-life

A

length of time required for half of the radioactive atoms in a sample to decay

217
Q

geologic time scale

A

timeline used to represent earth’s history

218
Q

era

A

major division of geologic time; usually divided into two or more periods

219
Q

period

A

division of geologic time into which eras are subdivided

220
Q

plate tectonics

A

geologic process, such as continental drift, volcanoes, and earthquakes, resulting from plate movement

221
Q

macroevolutionary patterns

A

changes in anatomy, phylogeny, ecology, and behavior that take place in clades larger than a single species

222
Q

background extinction

A

extinction caused by slow and steady process of natural selection

223
Q

mass extinction

A

event during which many species become extinct during a relatively short period of time

224
Q

gradualism

A

the evolution of a species by gradual accumulation of small genetic changes over long periods of time

225
Q

punctuated equilibrium

A

pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change

226
Q

adaptive radiation

A

process by which a single species of a small group of species evolves into several different forms

227
Q

convergent evolution

A

process by which unrelated organisms independently evolve similarities when adapting to similar environments

228
Q

coevolution

A

process by which two species evolve in response to changes in each other over time

229
Q

endosymbiotic theory

A

theory that proposes that eukaryotic cells formed from a symbiotic relationship among several different prokaryotic cells

Biology 9 (6 decks)

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