Unit 2 Biology Book Vocab

Front 1

Genome

Back 1

a cell's endowment of DNA, its gentic informtion.

Front 2

Chromosome

Back 2

DNA molecules are packaged into these

Front 3

somatic cells

Back 3

all body cells except the reproductive cells

Front 4

gametes

Back 4

Reproductive cells

Front 5

Sister Chromatids

Back 5

Replicatef forms of a chromosome joined together by the centromere and eventually separateed during mitosis or meiosis II

Front 6

cell cycle

Back 6

the life of a cell from the time it is first formed from a dividing parent cell until its own division into two cells, cell division process is an integral part of this

Front 7

chromtin

Back 7

a complex of DNA and associated protein molecules that make up eukaryotic chromosomes

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centomere

Back 8

The centralized region joining two sister chromatids

Front 9

Mitosis

Back 9

the division of the nucleus

Front 10

cytokinesis

Back 10

the division of the cytoplasm

Front 11

meiosis

Back 11

a two-stage type of cell division in sexually reproducing organisms that results in cells with half of the chromosome number of the original cell

Front 12

mitotic spindle

Back 12

the structure that consists of fibers made of microtubules and associated proteins

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centrosome

Back 13

a nonmenbranous organelle that fuctions thoughout the cell cycle to organize the cell's microtubules, the assembly of spindle microtubles start here

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aster

Back 14

a radial array of short microtubles, ectends from each centrosome

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kinetochore

Back 15

a structure of proteins associated with specific sections of chromosomal DNA a the centromere, Each of the two sister chromatids of a chromosome has one of these

Front 16

metaphase plate

Back 16

the imginary place where the cetomeres of the duplicated chromosomes are on between the spindles two poles.

Front 17

cleavage

Back 17

cytokinesis occurs by this in animal cells

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cleavage furrow

Back 18

a shallow groove in the cell surface near the old metaphase plate

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cell plate

Back 19

a double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

Front 20

binary fission

Back 20

means "division in half", Prokaryotes reproduce by this type of cell division

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cell cycle control system

Back 21

the sequential events of the cell cycle are dircted by this distint system, a cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle

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checkpoint of the cell cycle

Back 22

a critical control point where stop and go-ahead signals can regulate the cycle

Front 23

cyclin

Back 23

a protein that gets its name from its cyclically fluctuating concentration in the cell.

Front 24

growth factor

Back 24

is a protein released by certain cells that stimulates other cells to divide

Front 25

density-dependent inhibition

Back 25

a phenomenon in which crowded cells stop dividing

Front 26

anchorage dependence

Back 26

to divide cells must be attached to a substratum, such as the inside of a culture jar of the extracellular matrix of a tissue.

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transformation

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the process that converts a normal cell to a cancer cell

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benign tumor

Back 28

if teh abnormal cells remain at the origial site

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malignant tumor

Back 29

cancer cells become invasive enough to impair the functions of one or omre organs, if you have this kind of tumor it is said that you have cancer

Front 30

metastasis

Back 30

The spread of cancer cells to locations distant from their original site.

Front 31

Heredity

Back 31

the transmission of traits from one generation t othe next

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Variation

Back 32

offspring differ somewhat in appearance from parents and siblings

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Genetics

Back 33

the scientific study of heredity and hereditary variation

Front 34

Gametes

Back 34

reproductive cells, vehicles that transmit genes from one generation to the next.

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locus

Back 35

a gene's specific location along the length of a chromosome

Front 36

asexual reproduction

Back 36

reproducing offspring that are exact copies. In this a single individual is the sole parent and passes copies of all its genes to its offspring.

Front 37

clone

Back 37

a group of genetically idnetical individuals, these are produced by asexual reproduction

Front 38

sexual reproduction

Back 38

two parents give rise to offspring that have unique combinations of genes inherited from the two parents

Front 39

life cycle

Back 39

the generation-to-generation sequecne of stages in the reporductive history of an organism, from conception to productionof its own offspring

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karyotype

Back 40

an ordered display of chromosomes

Front 41

homologous chromosomes

Back 41

The pairs of chromosomes that match

Front 42

sex chromosomes

Back 42

the X and Y chromosomes

Front 43

autosomes

Back 43

all the chromosomes except for the sex chromosomes

Front 44

diploid cell

Back 44

cell that has a diploid number (2 chromosome sets) of chromosomes, abbreviated 2n

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haploid cell

Back 45

cells with one chromosome set. abbreviated n

Front 46

fertilization

Back 46

a haploid sperm cell from the father fuses with a haploid ovum from the mother. this a union of gametes, culminating in fusion of their nuclei.

Front 47

zygote

Back 47

the result of fertilization. It is a diploid cell because it contains two haploid sets of chromosomes.

Front 48

meiosis

Back 48

A type of cell division that reduces the number of sets of chromosomes from two to one in the gamets. This occurs only in the ovaries or testes and produce haploid cells.

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alternation of generations

Back 49

a type of life cycle that includes both diploid and haploid multicellular stages. One stage called sporophyte and the other called gametophyte.. This occurs in some species of algae and plants.

Front 50

sporophyte

Back 50

a diploiIn organisms undergoing alternations of generations, the multicelular diploid from that results from a union of gamestes and that meiotically produces haploid spores that grow into the gametophyte generation

Front 51

spores

Back 51

unlike a gamete, these give rise to a multicellular individual without fusing with another cell.

Front 52

gametophyte

Back 52

in organisms undergoing alternation of generations the multicellular haploid form that mitotically produces haploid gametes that unite and grow into the sporophyte generation

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Meiosis I

Back 53

The first division of a two-stage process of cell division in secually reproducing organisms that resultes in cells with half the chromsome number of the original cell.

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Meiosis II

Back 54

The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the chromsome number of the original cell

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synapsis

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duplicated homologous chromosomes line u and become physcially connected along their lenths by a zipper like protein structure

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crossing over

Back 56

Genetic rearrangement between nonsister chromatids

Front 57

recombinant chromsomes

Back 57

crossing over produces these, they are individual chromosmes that carry genes (DNA) derived from two different parents

Front 58

natural selection

Back 58

a mechanisms for evolutionary process. The basic idea is that a population can change over generations if individuals that posses certain hertiable traits leave more offspring than other individuals.

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evolutionary adaptation

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an accumulation of inheritd characteristics that enhance organisms ability to survie and reproduce in specific environments

Front 60

evolution

Back 60

a change over time in the genetic composition of a population

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taxonomy

Back 61

the branch of biology concerned with naming and classifying organisms that was founded by Linnaeus. Includes naming by Genus species

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Fossils

Back 62

remains or traces of organisms from the past. Most are found in sedimentary rocks formed from the sand and mud that settle to the botton of seas, lakes and marshes.

Front 63

Paleontology

Back 63

the study of fossils

Front 64

catastrophism

Back 64

the speculatoin that each boundary between strat represent a catastrophe that destroyed many of the species living at that time, rather than because of evolutionary change

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gradualism

Back 65

the idea that profound change can take place through the cumulative effect of slow but continuous processes.

Front 66

uniformitarianism

Back 66

the same geological processes are operating today as in the past and at the same rate.

Front 67

descent with modification

Back 67

the way darwin expressed his ideas on evolution instead of using the word evolution

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artificial selection

Back 68

selecting and breeding individuals that posses desired traits

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homology

Back 69

similarity resulting from common ancestry.

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homologous structures

Back 70

represent variations on a structural theme that was present in their common ancestors. Ex. mammalian forelimbs

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vestigial organs

Back 71

structures of margianal, if any, importance to the organism. They are remnants of structures that served important function in the organisms ancestors.

Front 72

biogeography

Back 72

the geographic distribution of species

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endemic

Back 73

refering to animals that are only found in one place in the world

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speciation

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origin of new species

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microevolution

Back 75

changes confined to a single gene pool

Front 76

macroevolution

Back 76

such evolutionary chabe about the species level. For example, the apprearance of feathers druing the evolution of birds from one group of dinosaurs.

Front 77

species

Back 77

Latin word meain kind or appearances

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biological species concept

Back 78

defines a species as a population or group of [opluations whose members have the potential to interbreed in nature and produce viable, fertile offspring with members of other populations

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reproductive isolation

Back 79

the existence of bilogical factors, that impede members of two species from producing viable, fertile hybrids.

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Prezygotic barriers

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impede mating b/w species or hinder the fertilization of ova if member of different species attempt to make

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Postzygotic barriers

Back 81

often prevent the hybrid zygote from developing into a vaible fertile adult

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morphological species concept

Back 82

characterizes a species by its body shape, size and toher structural features

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Paleontological species concept

Back 83

focuses on morphologically discrete species known only from the fossil record

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ecological speices concept

Back 84

view a species in terms of its ecological niche (where it lives) and its role in a bilogical community

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phylogenetic speices concept

Back 85

defines a species as a set of organisms with a unique gentic history

Front 86

allopatric speciation

Back 86

gene flow is interruped when a poplution is dived into geographically isolated subpopulations

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sympatric speciation

Back 87

a mode of speciation occurring as a result of a radical change in the genome of a subpopulation, reproductively isolating the subpopulation from the parent population

Front 88

polyploidy

Back 88

a mutational change in which some plant species have their origins in accidnets during cell division that result in extra sets of chromosomes

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autopolyploid

Back 89

a individal that has more than two chromosome sets, all derived from a single species.

Front 90

allopolyploid

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various mechanisms can change a sterile gybrid int a fertile polyploid know as this

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Adaptive Radiation

Back 91

The evolution of many diversely adapted species from a common ancestor upon introductions to various new environmental opportunities and challenges

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Punctuated equilibrium

Back 92

periods of apparent stasis punctuated by sudden change in an evolving species

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heterochrony

Back 93

an evolutionary change in the rate or timing of developmental events. Ex: an organisms shape depends in part on the relative growth rates of different body parts during development.

Front 94

allometric growth

Back 94

The proportioning that helps give a body its specific form

Front 95

paedomorphosis

Back 95

a condition that causes reproductive development accelerates compared to somatic development, the sexually mature stage of species may retain body features that were juvenile structures in an ancestral species

Front 96

homeotic genes

Back 96

determine such basic features as where a pair of wings and a pair of legs will develop on a bird or how a plant's flower parts are arranged

Front 97

species selection (end of ch 24)

Back 97

just as individual organisms undergo natural selection, species undergo this, in which the species that endure the longest and generate the most new offspring species determine the direction of major evolutionary trends.

Front 98

phylogeny (start of ch 25)

Back 98

the evolutionary history of a species or group of species

Front 99

systematics

Back 99

an analytical approach to understanding the diversity and relationships or organisms, both present day and extinct

Front 100

molecular systematics

Back 100

uses comparison of DNA, RNA and other molecules to infer evolutionary relationships b/w individual genes and even b/s entire genomes.

Front 101

fossil record

Back 101

based on the sequence in which fossils have accumulated in such strata

Front 102

analogy

Back 102

a potential red herring in constructing a phylogeny is similarity due to convergent evolution rather than to shared ancestry (homology).

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homoplasies

Back 103

analogous structures that have evolved independently

Front 104

Taxonomy

Back 104

an ordered division of organisms into catergories based on a set of characteristics used to assess similarities ad differences

Front 105

binomial

Back 105

the two part format of the scientific name, includes first the genus and the second is the specific epithet which is unique for each species w.in the genus

Front 106

phylogenetic trees

Back 106

Branching diagrams that depict hypotheses about evolutionary relationships

Front 107

cladogram

Back 107

patterns of shared characteristics that are depicted in a diamgram

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clade

Back 108

a group of species that includes an ancestral species and all its descendants.

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cladistics

Back 109

the analysis of how species may be grouped into clades

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monophyletic

Back 110

a valid clade, signifying that it consists of the ancestral species and all of its descendants.

Front 111

paraphyletic

Back 111

lacks information about some members of a clade so the grouping consists of an ancestral species and some, but not all, of the descendants.

Front 112

polyphyletic

Back 112

grouping of several species that lack a common ancestor.

Front 113

shared primitive character

Back 113

a character that is shared beyond the taxon we are trying to define

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shared derived character

Back 114

an evolutionary novelty unique to a particular clade.

Front 115

outgroup

Back 115

a species or group of species that is closely related to the ingroup but is less closely related than any of the ingroup members are to each other based on other evidence

Front 116

ingroup

Back 116

the various species we are studying

Front 117

phylogram

Back 117

the length of a branch reflects the number of changes that have taken place in a particular DNA sequence in the lineage

Front 118

ultrametric tree

Back 118

the branching pattern is the same as a hylogram but all the brances that can be traced from the common ancestor to the present are of equal length

Front 119

maximum parsimony

Back 119

a principle that states we should first investigate the simplest explanations that is consistent with the facts

Front 120

maximum likelihood

Back 120

a principle that states that given certain rules about how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events

Front 121

orthologous genes

Back 121

refers to homologous genes that are passed in a straight line from one generation to the next but have ended up in different gene pools because of speciation.

Front 122

Paralogous genes

Back 122

result from gene duplication, so they are found in more than one copy in the same genome

Front 123

molecular clock

Back 123

a yardstick for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates.

Front 124

neutral theory

Back 124

that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection

Front 125

horizontal gene transfer

Back 125

genes are transferred from one genome to another through mechanisms such as transposable elements, and perhaps through fusions of different organisms.

Front 126

protobionts
Start of Ch 26

Back 126

An aggregate of abiotically produced molecules surrounded by a membrane or membrane-like structure. These aided in reproductions and metabolism in early organic soup.

Front 127

ribozymes

Back 127

RNA catalysts- RNA can carry out a number of enzyme-like catalytic functions.

Front 128

radiometric dating

Back 128

common technique to date fossils, which is based on the decay of radioactive isotopes.

Front 129

Half-life

Back 129

the number of years it takes for 50% of the original sample to decay. This is used in radiometric dating.

Front 130

magnetic reversals

Back 130

Earth's north and south magnetic poles have reversed repeatedly in the past. They affect the entire plant and have left their record on rocks throughout the world.

Front 131

geologic record

Back 131

the geological history of earth, which is divided into three eons. Which include Archaean, Proterozoic and Precambrian.

Front 132

stromatolites

Back 132

The oldest known fossils from 3.5 byo which are rocklike structures composed of many layers of bacteria and sediment.

Front 133

serial endosymbiosis

Back 133

a sequence of endosymbiotic events, it is a hypothesis that supposes that mitochondria evolved before plastids

Front 134

genetic annealing

Back 134

The genome of eukaryotic cells may be the product of this, in which horizontal gene transfer occurred between many different bacterial and archaean lineages.

Front 135

Snowball Earth Hypothesis

Back 135

most life would have been confined to areas near deep-sea vents and hot springs or to those sparse regions of the ocean where enough ice had melted for sunlight to penetrate the surface waters.

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colonies

Back 136

The first multicellular organisms, they were collections of autonomously replicating cells.

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Pangaea

Back 137

About 250 m.y.a near the end of the paleozoic era, plate movements brought all the previously separated landmasses together into a supercontinent.

Front 138

three-domain system

Back 138

Includes Bacteria, Archaea and Eukarya- which are essentially superkingdoms

Front 139

Peptidoglycan
Start of Ch 27

Back 139

This is in most bacterial cell walls, and it is a network of modified-sugar polymers cross-linked by short polypeptides.

Front 140

Gram Stain

Back 140

A technique used to classify many bacterial species into two groups based on differences in cell wall composition.

Front 141

Gram-Positive

Back 141

This bacteria have simpler walls with a relatively large amount of peptidoglycan.

Front 142

Gram-negative

Back 142

This bacteria has less peptidoglycan and are structurally more complex, with an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids)

Front 143

capsule

Back 143

The cell wall of many prokaryotes is covered by this, it is a sticky later of polysaccharide of protein.

Front 144

Fimbriae

Back 144

Some prokaryotes stick to their substrate or to one another by means of these hair-like appendages- these are numerous and short.

Front 145

Pili

Back 145

Some prokaryotes stick to their substrate or to one another by means of hairlike appendages called pili. These are less numerous and longer

Front 146

Taxis

Back 146

movement towards or away from a stimulus, such as movement toward oxygen or movement away from a toxic substance.

Front 147

nucleoid region

Back 147

This is where the prokaryotic chromosome is located, it is part of the cytoplasm that appears lighter than the surrounding cytoplasm in electron micrographs.

Front 148

plasmids

Back 148

small rings of DNA that consist of only a few genes found in a typical prokaryotic cell.

Front 149

endospores

Back 149

A cell that is in a dormant stage (because the environment is lacking essential nutrient) that is very resistant to harsh environments.

Front 150

Photoautotrophs

Back 150

photosynthetic organisms- synthesize CO2 as its source for carbon.

Front 151

Chemoautotrophs

Back 151

Uses CO2 as carbon source and oxidize inorganic substances as a mode of nutrition.

Front 152

Photoheterotrophs

Back 152

LIght for energy but obtains carbon in an organic from

Front 153

Chemoheterotrophs

Back 153

must consuem organic molecules for both energy and carbon

Front 154

Obligate aerobes

Back 154

us O2 for cellular repirations and connot grow without it

Front 155

Faculative Anaerobes

Back 155

use O2 if it is present but can also grow by fermentation in an anaerobic environment.

Front 156

Obligate anaerobes

Back 156

are poisoned by O2. Some of these live exclusively by fermentation and others extract energy by anaerobic respiration.

Front 157

Anaerobic respirations

Back 157

substances other than O2, such are nitrate ions or sulfate ions, accept electrons at the downhill end of electron transport chains.

Front 158

biofilms

Back 158

surface coating colonies that use metabolic cooperation. Cells in a colony secrete signaling molecules that recruit nearby cells, causing the colony to grow.

Front 159

extremophiles

Back 159

speices that live in environments so extreme that few other orgnaism can survive there.

Front 160

Extreme thermophiles

Back 160

prokaryotes that thrive in very hot environments

Front 161

Extreme halophiles

Back 161

prokaryontes that live in highly saline environments

Front 162

Methanogens

Back 162

Prokaryotes that use Co2 to oxidize H2, and releasing methane as a waste product.

Front 163

prokaryotic decomposers

Back 163

chemoheterotrphic prokaryotes that break down corpses, dead vegetation, and waste products, thereby unlocking supplies of carbon, nitrogen and other elements.

Front 164

symbiosis

Back 164

an ecological relationship b/w organisms of different species that are in direct contact

Front 165

host

Back 165

the larger of organisms in a symbiotic relationship

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symbiont

Back 166

the smaller of organisms in a symbiotic relationship

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mutualism

Back 167

both symbiotic organisms benefit

Front 168

commensalism

Back 168

one organism benefits while neither harming nor helping the other in any significant way

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parasitism

Back 169

one organisms called the parasite, benefits at the expense of the host

Front 170

Exotoxins

Back 170

preteins secreted by prokaryotes

Front 171

Endotoxins

Back 171

Lipopolysaccharide componets of teh outer membrane of gram-negative bacteria. They are released only when the bacteria die and their cell walls break down.

Front 172

bioremediation

Back 172

the use of organisms to remove pollutants from soil, air or water