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172 Cards in this Set

  • Front
  • Back
a cell's endowment of DNA, its gentic informtion.
DNA molecules are packaged into these
somatic cells
all body cells except the reproductive cells
Reproductive cells
Sister Chromatids
Replicatef forms of a chromosome joined together by the centromere and eventually separateed during mitosis or meiosis II
cell cycle
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
a complex of DNA and associated protein molecules that make up eukaryotic chromosomes
The centralized region joining two sister chromatids
the division of the nucleus
the division of the cytoplasm
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
mitotic spindle
the structure that consists of fibers made of microtubules and associated proteins
a nonmenbranous organelle that fuctions thoughout the cell cycle to organize the cell's microtubules, the assembly of spindle microtubles start here
a radial array of short microtubles, ectends from each centrosome
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
metaphase plate
the imginary place where the cetomeres of the duplicated chromosomes are on between the spindles two poles.
cytokinesis occurs by this in animal cells
cleavage furrow
a shallow groove in the cell surface near the old metaphase plate
cell plate
a double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.
binary fission
means "division in half", Prokaryotes reproduce by this type of cell division
cell cycle control system
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
checkpoint of the cell cycle
a critical control point where stop and go-ahead signals can regulate the cycle
a protein that gets its name from its cyclically fluctuating concentration in the cell.
growth factor
is a protein released by certain cells that stimulates other cells to divide
density-dependent inhibition
a phenomenon in which crowded cells stop dividing
anchorage dependence
to divide cells must be attached to a substratum, such as the inside of a culture jar of the extracellular matrix of a tissue.
the process that converts a normal cell to a cancer cell
benign tumor
if teh abnormal cells remain at the origial site
malignant tumor
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
The spread of cancer cells to locations distant from their original site.
the transmission of traits from one generation t othe next
offspring differ somewhat in appearance from parents and siblings
the scientific study of heredity and hereditary variation
reproductive cells, vehicles that transmit genes from one generation to the next.
a gene's specific location along the length of a chromosome
asexual reproduction
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.
a group of genetically idnetical individuals, these are produced by asexual reproduction
sexual reproduction
two parents give rise to offspring that have unique combinations of genes inherited from the two parents
life cycle
the generation-to-generation sequecne of stages in the reporductive history of an organism, from conception to productionof its own offspring
an ordered display of chromosomes
homologous chromosomes
The pairs of chromosomes that match
sex chromosomes
the X and Y chromosomes
all the chromosomes except for the sex chromosomes
diploid cell
cell that has a diploid number (2 chromosome sets) of chromosomes, abbreviated 2n
haploid cell
cells with one chromosome set. abbreviated n
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.
the result of fertilization. It is a diploid cell because it contains two haploid sets of chromosomes.
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.
alternation of generations
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.
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
unlike a gamete, these give rise to a multicellular individual without fusing with another cell.
in organisms undergoing alternation of generations the multicellular haploid form that mitotically produces haploid gametes that unite and grow into the sporophyte generation
Meiosis I
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.
Meiosis II
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
duplicated homologous chromosomes line u and become physcially connected along their lenths by a zipper like protein structure
crossing over
Genetic rearrangement between nonsister chromatids
recombinant chromsomes
crossing over produces these, they are individual chromosmes that carry genes (DNA) derived from two different parents
natural selection
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.
evolutionary adaptation
an accumulation of inheritd characteristics that enhance organisms ability to survie and reproduce in specific environments
a change over time in the genetic composition of a population
the branch of biology concerned with naming and classifying organisms that was founded by Linnaeus. Includes naming by Genus species
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.
the study of fossils
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
the idea that profound change can take place through the cumulative effect of slow but continuous processes.
the same geological processes are operating today as in the past and at the same rate.
descent with modification
the way darwin expressed his ideas on evolution instead of using the word evolution
artificial selection
selecting and breeding individuals that posses desired traits
similarity resulting from common ancestry.
homologous structures
represent variations on a structural theme that was present in their common ancestors. Ex. mammalian forelimbs
vestigial organs
structures of margianal, if any, importance to the organism. They are remnants of structures that served important function in the organisms ancestors.
the geographic distribution of species
refering to animals that are only found in one place in the world
origin of new species
changes confined to a single gene pool
such evolutionary chabe about the species level. For example, the apprearance of feathers druing the evolution of birds from one group of dinosaurs.
Latin word meain kind or appearances
biological species concept
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
reproductive isolation
the existence of bilogical factors, that impede members of two species from producing viable, fertile hybrids.
Prezygotic barriers
impede mating b/w species or hinder the fertilization of ova if member of different species attempt to make
Postzygotic barriers
often prevent the hybrid zygote from developing into a vaible fertile adult
morphological species concept
characterizes a species by its body shape, size and toher structural features
Paleontological species concept
focuses on morphologically discrete species known only from the fossil record
ecological speices concept
view a species in terms of its ecological niche (where it lives) and its role in a bilogical community
phylogenetic speices concept
defines a species as a set of organisms with a unique gentic history
allopatric speciation
gene flow is interruped when a poplution is dived into geographically isolated subpopulations
sympatric speciation
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
a mutational change in which some plant species have their origins in accidnets during cell division that result in extra sets of chromosomes
a individal that has more than two chromosome sets, all derived from a single species.
various mechanisms can change a sterile gybrid int a fertile polyploid know as this
Adaptive Radiation
The evolution of many diversely adapted species from a common ancestor upon introductions to various new environmental opportunities and challenges
Punctuated equilibrium
periods of apparent stasis punctuated by sudden change in an evolving species
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.
allometric growth
The proportioning that helps give a body its specific form
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
homeotic genes
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
species selection (end of ch 24)
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.
phylogeny (start of ch 25)
the evolutionary history of a species or group of species
an analytical approach to understanding the diversity and relationships or organisms, both present day and extinct
molecular systematics
uses comparison of DNA, RNA and other molecules to infer evolutionary relationships b/w individual genes and even b/s entire genomes.
fossil record
based on the sequence in which fossils have accumulated in such strata
a potential red herring in constructing a phylogeny is similarity due to convergent evolution rather than to shared ancestry (homology).
analogous structures that have evolved independently
an ordered division of organisms into catergories based on a set of characteristics used to assess similarities ad differences
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 the genus
phylogenetic trees
Branching diagrams that depict hypotheses about evolutionary relationships
patterns of shared characteristics that are depicted in a diamgram
a group of species that includes an ancestral species and all its descendants.
the analysis of how species may be grouped into clades
a valid clade, signifying that it consists of the ancestral species and all of its descendants.
lacks information about some members of a clade so the grouping consists of an ancestral species and some, but not all, of the descendants.
grouping of several species that lack a common ancestor.
shared primitive character
a character that is shared beyond the taxon we are trying to define
shared derived character
an evolutionary novelty unique to a particular clade.
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
the various species we are studying
the length of a branch reflects the number of changes that have taken place in a particular DNA sequence in the lineage
ultrametric tree
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
maximum parsimony
a principle that states we should first investigate the simplest explanations that is consistent with the facts
maximum likelihood
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
orthologous genes
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.
Paralogous genes
result from gene duplication, so they are found in more than one copy in the same genome
molecular clock
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.
neutral theory
that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection
horizontal gene transfer
genes are transferred from one genome to another through mechanisms such as transposable elements, and perhaps through fusions of different organisms.
Start of Ch 26
An aggregate of abiotically produced molecules surrounded by a membrane or membrane-like structure. These aided in reproductions and metabolism in early organic soup.
RNA catalysts- RNA can carry out a number of enzyme-like catalytic functions.
radiometric dating
common technique to date fossils, which is based on the decay of radioactive isotopes.
the number of years it takes for 50% of the original sample to decay. This is used in radiometric dating.
magnetic reversals
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.
geologic record
the geological history of earth, which is divided into three eons. Which include Archaean, Proterozoic and Precambrian.
The oldest known fossils from 3.5 byo which are rocklike structures composed of many layers of bacteria and sediment.
serial endosymbiosis
a sequence of endosymbiotic events, it is a hypothesis that supposes that mitochondria evolved before plastids
genetic annealing
The genome of eukaryotic cells may be the product of this, in which horizontal gene transfer occurred between many different bacterial and archaean lineages.
Snowball Earth Hypothesis
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.
The first multicellular organisms, they were collections of autonomously replicating cells.
About 250 m.y.a near the end of the paleozoic era, plate movements brought all the previously separated landmasses together into a supercontinent.
three-domain system
Includes Bacteria, Archaea and Eukarya- which are essentially superkingdoms
Start of Ch 27
This is in most bacterial cell walls, and it is a network of modified-sugar polymers cross-linked by short polypeptides.
Gram Stain
A technique used to classify many bacterial species into two groups based on differences in cell wall composition.
This bacteria have simpler walls with a relatively large amount of peptidoglycan.
This bacteria has less peptidoglycan and are structurally more complex, with an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids)
The cell wall of many prokaryotes is covered by this, it is a sticky later of polysaccharide of protein.
Some prokaryotes stick to their substrate or to one another by means of these hair-like appendages- these are numerous and short.
Some prokaryotes stick to their substrate or to one another by means of hairlike appendages called pili. These are less numerous and longer
movement towards or away from a stimulus, such as movement toward oxygen or movement away from a toxic substance.
nucleoid region
This is where the prokaryotic chromosome is located, it is part of the cytoplasm that appears lighter than the surrounding cytoplasm in electron micrographs.
small rings of DNA that consist of only a few genes found in a typical prokaryotic cell.
A cell that is in a dormant stage (because the environment is lacking essential nutrient) that is very resistant to harsh environments.
photosynthetic organisms- synthesize CO2 as its source for carbon.
Uses CO2 as carbon source and oxidize inorganic substances as a mode of nutrition.
LIght for energy but obtains carbon in an organic from
must consuem organic molecules for both energy and carbon
Obligate aerobes
us O2 for cellular repirations and connot grow without it
Faculative Anaerobes
use O2 if it is present but can also grow by fermentation in an anaerobic environment.
Obligate anaerobes
are poisoned by O2. Some of these live exclusively by fermentation and others extract energy by anaerobic respiration.
Anaerobic respirations
substances other than O2, such are nitrate ions or sulfate ions, accept electrons at the downhill end of electron transport chains.
surface coating colonies that use metabolic cooperation. Cells in a colony secrete signaling molecules that recruit nearby cells, causing the colony to grow.
speices that live in environments so extreme that few other orgnaism can survive there.
Extreme thermophiles
prokaryotes that thrive in very hot environments
Extreme halophiles
prokaryontes that live in highly saline environments
Prokaryotes that use Co2 to oxidize H2, and releasing methane as a waste product.
prokaryotic decomposers
chemoheterotrphic prokaryotes that break down corpses, dead vegetation, and waste products, thereby unlocking supplies of carbon, nitrogen and other elements.
an ecological relationship b/w organisms of different species that are in direct contact
the larger of organisms in a symbiotic relationship
the smaller of organisms in a symbiotic relationship
both symbiotic organisms benefit
one organism benefits while neither harming nor helping the other in any significant way
one organisms called the parasite, benefits at the expense of the host
preteins secreted by prokaryotes
Lipopolysaccharide componets of teh outer membrane of gram-negative bacteria. They are released only when the bacteria die and their cell walls break down.
the use of organisms to remove pollutants from soil, air or water