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Biology 102
1st Exam
294
Biology
Undergraduate 2
03/31/2010

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Term
Binary Fission
Definition
Prokaryotes carry out this simple form of splitting into two cells
Term
Chromosome
Definition
A molecule of DNA together with protein that help to organize
Term
Cytokinesis
Definition
This occurs with a cleavage furrow in animal cells and a cell plate in plant cells
Term
DNA
Definition
A molecule composed of a string of nucleotides(letters). Phosphates & Sugars serve as backbone. Hydrogen bonds between nucleotides
Term
Gene
Definition
The unit of heredity that specifies a particular trait. Provides the cell with information for building a particular trait. A gene is a segment of DNA that encodes the sequence of amino acids in a particular protein.
Term
Homologous Chromosomes
Definition
Two identical copies of the same chromosome, each coming from a different parent.
Term
Histones
Definition
Proteins with positive charges around which the DNA molecule coils.
Term
Metastases
Definition
The spread of cancer throughout the body
Term
Mitotic Cell Division
Definition
A cell cycle in which Eukaryotic cells divide consisting of
a) Mitosis- Nuclear division
b) Cytokinesis- cytoplasmic division
The end result is two daughter cells genetically identical to one another and to the parent cell
Term
What are the phases in the Eukaryotic Cell Cycle?
Definition
Interphase, G1, G0, S, G2. Mitosis; Prophase, Metaphase, Anaphase, Telophase. Cytokinesis
Term
What happens in the interphase?
Definition
Cell growth and replication of DNA
Term
What happens in the G1 phase?
Definition
Cell is sensitive to signals (will divide or not). Cells may also differentiate (become specialized).
Term
What happens in the S stage?
Definition
Synthesis of DNA, Chromosomes are replicated
Term
What happens in the G2 phase?
Definition
More cell growth, the organelles are replicated
Term
What happens in the G0 phase?
Definition
Resting Phase, No Cell division
Term
What are the four phases of Mitotic Cell Division?
Definition
Prophase, Metaphase, Anaphase, Telophase
Term
What happens in the Prophase?
Definition
DNA condenses into chromosomes. The mitotic spindle is formed. The nuclear envelope begins to break down
Term
What happens in the Metaphase?
Definition
Chromosomes align on a plane in the center of each cell. The kinotochore fibers connect to the center of each kinotochore from opposite sides of the centromeres
Term
What happens in the anaphase?
Definition
The centromeres replicate. The sister chromatids separate and move to different sides of the cell.
Term
What happens in the telophase?
Definition
The chromosomes decondense. The nuclear envelope reappears
Term
What happens in cytokinesis?
Definition
The cytoplasm divides. Two daughter cells are formed. Each are identical to each other and to the parent cell
Term
Describe Binary Fission
Definition
DNA replicates by "unzipping" the DNA and replacing the complementary nucleotides. After DNA has been copied the cell grows, resulting in elongation. The DNA molecules move towards each end of the cell and attaching to the membrane. The cell begins to split. New plasma membrane and cell wall are added to each of the DNA copies The plasma membrane pushes inward to divide the cell into two daughter cells.
Term
Describe a Prokaryotic Chromosome
Definition
Circular with double stranded DNA
Term
Describe a Eukaryotic Chromosome
Definition
Composed of DNA and protien. Chromosomes look as though they are a line with a ball in the center. The center is called a centromere. They are in pairs called homologues.
Term
What is P53?
Definition
Protein 53 triggers the repair of damaged DNA, and triggers the destruction of DNA damaged beyond repair. If P53 than it fails to repair DNA or destroy damaged DNA. The cell than reproduces regardless of the state of the cell.
Term
What are the checkpoints in the cell cycle?
Definition
G1, G2, and the M phase
Term
Gregor Mendel
Definition
in 1857, began to study the laws that govern the inheritance of traits and the existence of genes that carry traits from one generation to the next
Term
Frederick Griffith
Definition
1928, tested mice and found that hereditary information in dead cells can transform living cells
Term
Oswald Avery
Definition
1944 came up with the transformative principle
Term
Transformative Principle
Definition
A series of experiments that proved that the transforming substance was DNA
Term
Erwin Chargraff
Definition
1947, The amount of c=g and a=t in DNA
Term
Hershey- Chase Experiments
Definition
1952, Elucidated that genes are made of DNA, DNA structure still remained unknown
Term
Rosalind Franklin
Definition
1953, Using Maurice Wilkins crystalline DNA, photographs X Ray diffraction patterns
Term
Francis Crick and James Watson
Definition
1953, deduced structure of DNA and predicted that DNA replicated in a semi-conservative manner
Term
What is the structure of a nucleotide?
Definition
A phosphate group, Nitrogenous base, and a sugar group
Term
What are purines?
Definition
the large bases, Adenine & guanine
Term
What are pyridimines?
Definition
small bases, Thymine, Cytosine, and Uracil
Term
How are base pairs bonded?
Definition
hydrogen bonds
Term
What is conservative replication?
Definition
Mode of DNA replication in which an intact double helix acts as a template for a new double helix. In which the initial double helix splits, complementary strands are formed on each of the original strands, and than the original strand re-joins, and the newly formed strands come together to form daughter DNA
Term
What is semi-conservative replication?
Definition
Produces two copies that each contain one of the original strands and one new strand
Term
What is dispersive replication?
Definition
Produces two copies of the DNA, both containing distinct regions of DNA composed of either both original strands or both new strands
Term
What is the meselson- stahl experiment?
Definition
1958, using 14N and 15N, they found that after replication DNA contained an intermediate amount of the two isotopes, suggesting semi- conservative replication
Term
What are the critical enzymes for DNA replication?
Definition
DNA helicase, DNA polymerase, DNA ligase
Term
What does DNA helicase do?
Definition
seperates the strands of a DNA molecule, breaking the hydrogen bonds in the steps of the ladder. The DNA helix unwinds and a replication bubble forms
Term
DNA polymerase
Definition
helps to synthesize new pieces of DNA
Term
DNA ligase
Definition
Joins small DNA segments on the lagging strand
Term
Describe how DNA copies itself on the leading strand?
Definition
DNA replication starts at the replication site, replication moves towards the replication fork, helicase breaks hydrogen bonds to seperate DNA strands, single binding protein supports the seperated strands of DNA,RNA primase adds an RNA primer at the beginning of the DNA strand Polymerase initiates the process of replication, and adds nucleotides to preexisting nucleotides, Nucleotide replacement enzyme will replace RNA primer with the DNA
Term
Describe how DNA copies itself on the lagging strand
Definition
Built in segments,Replication moves away from the replication fork, RNA primase puts primers at each new section, Polymerase adds nucleotides to preexisting nucleotides, Nucleotide replacement enzyme will replace the RNA primer, DNA ligase joins the ends of the newly synthesized segments after primers have been removed
Term
What are the segments called in lagging strand replication?
Definition
Okazaki fragments
Term
In which way does DNA replicate?
Definition
from the 3 prine to 5 prine
Term
What is a mutation?
Definition
Change in base sequence of one or more genes
Term
What is recombination?
Definition
Change in the position of a portion of a gene
Term
What happens with there are mutations or recombination in germ line tissue?
Definition
Provides the raw material for evolution
Term
What happens with mutations in somatic tissue?
Definition
Can have an immediate impact if the genes affected alter the development or regulate cell division
Term
What is base substitution?
Definition
Substitution of one or a few bases
Term
What is insertion?
Definition
Additional copies of a repeated 3-base sequence
Term
What is deletion?
Definition
Loss of one or a few bases
Term
What is chromosomal rearrangement?
Definition
genes are rearranged on a chromosome
Term
What is insertional inactivation?
Definition
addition of a transposon within a gene
Term
Transformation
Definition
The griffith experiment showed how DNA can be passed from dead strains of pathogenic baterium to transform a non-virulent strain into one that is pathogenic, thus proving that DNA is the genetic material
Term
Nucleotides
Definition
The building blocks of the nucleic acids
Term
Carcinogen
Definition
Agents thought to cause cancer
Term
Base pairs
Definition
Hydrogen bonds form between the pairing bases inside the DNA molecule, keeping the molecule at a constant thickness
Term
Mutagen
Definition
An agent(usually radiation or chemical) that causes damage to DNA
Term
Germ Line
Definition
Possess genetic material that can be passed on, germline cells undergo mitosis to produce gametes
Term
Somatic Cells
Definition
Genetic information cannot be passed on, non reproductive cells
Term
Proof reading function of the DNA polymerase
Definition
3 exo-nuclease site catalyzes the removal of several nucleotides from the 3 prine end of the growing strand when a wrong base is added to DNA strand. A mutation is detected by the size of the nucleotides
Term
What are gametes?
Definition
A haploid reproductive cell. Upon fertilization its nucleus fuses with that of another gamete cell of the opposite sex
Term
what is a zygote?
Definition
The diploid cell resulting from the fusion of male and female gametes
Term
diploid
Definition
A cell with a double set of chromosomes
Term
what is a haploid cell?
Definition
a cell with only one set of chromosomes
Term
Syngamy
Definition
Fertilization, the union of male and female gametes
Term
Sexual reproduction
Definition
Alternation of meiosis and fertilization (germ line cells)
Term
Asexual reproduction
Definition
mitotic division(or binary fission) (somatic cells)
Term
Pierre- Joseph Van Beneden
Definition
1887; proposed that gametes are haploid and join to produce a zigote by fertilization or syngamy
Term
What are the disadvantages of sexual reproduction?
Definition
disruption of advantageous genes & recombination not likely to improve complex adaptions
Term
DNA repair hypothesis
Definition
Synapsis may have evolved as means to repair damaged DNA
Term
Muller's Ratchet
Definition
1965, as mutations accumulate in asexually reproducing species, sexual reproduction may have evolved to keep the number of mutations down
Term
The red queen hypothesis
Definition
Sexual reproduction allows alleles that may seem detrimental to exist until they have the possibility to be useful as species try to keep up with changing physical conditions and biological challenges
Term
What are the unique Characteristics of meiosis?
Definition
Crossing over, synapsis, & reduction division
Term
What is crossing over?
Definition
An essential element of meiosis occuring during prophase when nonsister chromatids exchange portions of DNA strands, because of crossing over no haploid cells are the same
Term
Synapsis
Definition
The close pairing of homologous chromosomes that occurs early in prophase 1 of meiosis. With the genes of chromosomes thus aligned, a DNA strandof one homologue can pair with the complementary DNA strand of another
Term
Reduction Division
Definition
The first cell division in meiosis, where germ line cells are formed. A unique event in which the chromosome number is reduced from diploid(46 chromosomes) to haploid (23 chromosomes)
Term
Independent Assortment
Definition
Occurs because the orientation of chromosomes on the metaphase plate is random. Each of the many possible orientations results in gametes with different combinations of parental chromosomes
Term
Random Fertilization
Definition
mechanism that produces genetic variation in the process of sexual reproduction
Term
What are the Evolutionary Consequences of sex?
Definition
Sexual reproduction has the capacity to generate new genetic combinations, Independent assortment, Crossing Over, Random Fertilization, Importance of generating diversity
Term
Meiosis
Definition
The type of cell division that happens only in germ cells and leads to the production of gametes
Term
In meiosis, what happens in prophase I?
Definition
Homologous chromosomes further condense and pair. Crossing Over occurs, spindle fibers form.
Term
In meiosis, What happens in Metaphase I?
Definition
Microtubule spindle apparatus attaches to chromosomes. Homologous pairs align along spindle equator.
Term
In meiosis, what happens in anaphase I?
Definition
Homologous pairs of chromosomes separate and move to opposite poles
Term
In meiosis, what happens in telophase I?
Definition
One set of paired chromosomes arrives at each pole, and nuclear division begins.
Term
In meiosis, What happens in prophase II?
Definition
Chromosomes recondense. Spindle fibers form between centrioles
Term
In meiosis, what happens in metaphase II?
Definition
Microtubule spindle apparatus attaches to chromosomes. Chromosomes align along the spindle.
Term
In meiosis, what happens in anaphase II?
Definition
Sister chromatids seperate and move to opposite poles
Term
In Meiosis, what happens in telophase II?
Definition
Chromatids arrive at each pole, and cell division begins
Term
What is the end result of meiosis
Definition
When cell division is complete, Each cell ends up with half the original number of chromosomes, four haploid daughter cells
Term
What is the central dogma of Molecular Biology?
Definition
DNA --> RNA --> Protein
The key organization used by cells to express their genes
Term
Transcription
Definition
The process whereby a messenger RNA molecule is synthesized from a portion of the DNA molecule in the nucleus, and is the first step in gene expression
Term
Translation
Definition
The second stage of gene expression in which a ribosome assembles a poly peptide, using the mRNA to specify the amino acids
Term
describe what happens in Transcription
Definition
RNA polymerase binds to one strand of a DNA double helix at a particular site called the promoter and then moves along the DNA strand, as it moves along it pairs each nucleotide with the complementary RNA version, building an mRNA chain in the 5' to 3' direction, the mRNA strand is then sent from the nucleus into the cytoplasm
Term
The protein making factory
Definition
Ribosomes use mRNA to direct the assembly of polypeptides
Term
Ribosomes
Definition
Ribosomes are composed of two subunits a large subunit(consisting of three sites E,P, &A) and a small subunit
Term
Describe what happens in translation
Definition
the large ribosomal subunit and the small ribosomal subunit attach to the mRNA, the mRNA will pass through the whole ribosomal unit three nucleotides at a time. A tRNA molecule first binds to the A site in the ribosome bringing a new amino acid to fit that codon. As each new tRNA brings in an amino acid to each new codon presented at the A site, the old tRNA paired with the previous codon is passed over to the P site where peptide bonds form between the incoming amino acid and the growing peptide chain. The tRNA in the P site eventually shifts to the E site ( the exit site), and the amino acid is attached to the end of a growing amino acid chain. The tRNA is then released. Translation continues unil a stop codon is encountered which signals the end of the polypeptide. The ribosome complex falls apart and the polypeptide is released into the cell
Term
what is tRNA?
Definition
transfer RNA, brings amino acids to the ribosome
Term
What is rRNA?
Definition
Ribosomal RNA ( the large subunit and small subunit)
Term
Exons
Definition
A section of a gene that contains a coding region, the exons provide the instructions for making a protein
Term
Intron
Definition
Extra nucleotide sequences in DNA that code for nothing
Term
Operon
Definition
A cluster of genes that is transcribed as a unit
Term
Genetic Code
Definition
Each three nucleotide block in a gene correspondes to a specific amino acid
Term
Codon
Definition
The three nucleotide sequence on mRNA that corresponds to an amino acid
Term
Promoter
Definition
The site on the DNA to which the RNA polymerase binds
Term
Repressor
Definition
The regulatory protein
Term
Enhancer
Definition
Help RNA polymerase find its binding site
Term
Anti Codon
Definition
The three nucleotide sequence on the tRNA molecule that is complementary to the mRNA codon
Term
Transposons
Definition
Jumping genes; can move from one chromosome to another
Term
Repressor
Definition
The regulatory protein
Term
Mature mRNA
Definition
contains only exons, RNA complexes exise out the introns and join the exons
Term
Primary RNA transcript
Definition
contains both introns and exons
Term
alternative splicing
Definition
By using different combinations of the same exons, different proteins can be created
Term
Multigene Families
Definition
Most eukaryotic genes exist in multiple copies called multigene families
Term
CAP (activator)
Definition
Required for RNA polymerase to operate correctly at the operon, binds to DNA when glucose and lactose levels are low, but transcripion only proceeds when lactose is present. Activators work with repressors to control transcription in the lac operon
Term
Mendels first law of heredity
Definition
Segregation: The two alleles of a trait separate from each other during the formation of gametes, so that half of the gametes will carry one copy and half will carry the other copy
Term
Dihybrid
Definition
the result of crossing two individuals who are true breeding for two different characters. F1 result
Term
Mendel's Second Law of Heredity
Definition
Independent Assortment: Genes located on different chromosomes are inherited independently of one another
Term
Continuous Variation
Definition
Characters can show a range of small differences when multiple genes act jointly to influence a character
Term
Pleiotropic effects
Definition
an allele that has more than one effect on a phenotype
Term
Incomplete Dominance
Definition
Not all alternative alleles are either fully dominant or fully recessive in heterozygotes
Term
Environmental Effects
Definition
The degree to which many alleles are expressed depends on the environment
Term
Epistasis
Definition
One gene modifies the phenotypic expression produced by the other
Term
Codominance
Definition
A gene may have more than two alleles in a population
Term
Linkage
Definition
the tendency of close together genes to segregate together
Term
Nondisjunction
Definition
the failure of chromosome to separate correctly during either meiosis one or meiosis two
Term
Aneuploidy
Definition
an abnormal chromosome number
Term
Down Syndrome
Definition
Down syndrome is caused by having an extra copy of chromosome 21
Term
Down Syndrome
Definition
Down syndrome is caused by having an extra copy of chromosome 21
Term
Cistic Fibrosis
Definition
Resessive genetic disorder
Term
Sickle Cell Anemia
Definition
Recessive heredity disorder, affected individuals are homozygous recessive and carry a mutated gene that produces a defective version of hemoglobin. Confers resistence to malaria
Term
Tay Sachs disease
Definition
disease caused by recessive allele, deteriorates the brain
Term
Huntingtons Disease
Definition
Dominant genetic disorder, deterioration of brain cells, every individual who carries the allele expresses the disorder
Term
amniocentesis & chorionic villus sampling
Definition
checking for chromosomal analysis
Term
Sexual Reproduction
Definition
occurs when a new individual is formed by the union of two cells
Term
Parthenogenesis
Definition
A special type of reproduction in which offspring are produced from unfertilized eggs
Term
Hermaphroditism
Definition
a reproductive strategy in which one individual has both testes and sperm and so can produce both sperm and eggs, most hermaphroditic organisms require another individual to reproduce
Term
Sequential hermaphroditism
Definition
A process in which individuals can change their sex
Term
protogyny
Definition
in sequential hermaphroditism, changing from female to male
Term
protandry
Definition
in sequential hermaphroditism, changes from male to female
Term
External fertilization
Definition
gametes are released into the water, common in amphibians and bony fish
Term
Internal Fertilization
Definition
male gametes are introduced into the female reproductive tract
Term
copulation
Definition
the introduction of sperm by the male into the female body
Term
Oviparity
Definition
The eggs are fertilized internally but complete development happens outside the mothers body; most reptiles, all birds
Term
ovoviviparity
Definition
the fertilized eggs complete development inside the mother and depend on yolk exclusively for nourishment before being born alive. Cartilaginous fish, some bony fish, and many reptiles
Term
viviparity
Definition
the young develop within the mother and obtain nourishment from their mothers blood before being born alive. Almost most mammals, some catilaginous fish, some amphibians and reptiles
Term
Marsupials
Definition
Give birth to fetuses that are incompletely developed, they complete their development in the pouch of their mothers skin
Term
Placental Mammals
Definition
Retain their young within the mothers uterus
Term
XY
Definition
The embryo is male and will carry a gene of the Y chromosome whose product converts gonads into testes
Term
XX
Definition
The embryo is a female and the gonads will become ovaries
Term
SRY
Definition
Gene on the Y chromosome that determines whether or not developing embryo is male. Once testes form in the embryo, they secrete testosterone that influences other male traits
Term
Estrus
Definition
Female mammals undergo cycles in which they are fertile
Term
Monotreme
Definition
Urinary, Defecatory, and reproductive systems all open into a single duct, Lay water tight eggs
Term
Induced ovulators
Definition
Females ovulate only after copulation as a result of a reflex stimulation of LH, Extremely fertile
Term
Estrous Cycle
Definition
Changes in the secretion of FSH and LH by the anterior pituitary causes changes in egg cell development and hormone secretion in the ovaries
Term
Estrous Cycle
Definition
Changes in the secretion of FSH and LH by the anterior pituitary causes changes in egg cell development and hormone secretion in the ovaries
Term
Estrous Cycle
Definition
Changes in the secretion of FSH and LH by the anterior pituitary causes changes in egg cell development and hormone secretion in the ovaries
Term
Ejaculation
Definition
The forceful ejection of 2 to 5 ml of semen, Males with fewer than 20 million sperm per ml are considered sterile
Term
Primary Oocytes
Definition
A females ovaries contain some 2 million oocytes, all of which have begun the first meiotic division, each oocytes waits to recieve the proper developmental signal to continue on with meiosis
Term
Ovulation
Definition
One or a few of these oocytes are initiated to continue their development, FSH is the signal. Only about 400 of the 2 million oocytes a woman is born with is actually ovulated
Term
endometrium
Definition
The uterus is lined with a stratified epithelial membrane, the surface of the endometrium is shed during menstration
Term
Follicular Phase
Definition
First phase in the menstrual cycle, In which an egg reaches maturation and is ovulated
Term
Luteal Phase
Definition
Second Phase in menstrual cycle, where the body prepares for pregnancy
Term
Hypothalamus
Definition
Controls the family of hormones that coordinates the phases of menstration
Term
Cleavage
Definition
Period of cell division immediately after fertilization, The zygote divides rapidly into a larger and larger number of smaller and smaller cells
Term
Morula
Definition
Resulting from cleavage, it is a mass of about 36 cells
Term
Blastomere
Definition
Each individual cell in the morula
Term
blastocyst
Definition
Hallow ball of 500- 2,000 cells, The embryonic stage that implants in the endometrium
Term
Blastocoel
Definition
Fluid filled cavity within the blastocyst, within the ball is an inner cell mass concentrated at one pole that goes on to form the developing embryo
Term
Trophoblast
Definition
The outer sphere of cells on the blastocyst, that releases hCG which maintains the corpus luteum and prevents menstration
Term
Amnion
Definition
Membrane which encloses the developing embryo
Term
Chorion
Definition
Forms from the trophoblast and interacts with the uterine tissue to form the placenta
Term
Placenta
Definition
Connects the developing embryo to the blood supply of the mother
Term
Why must fertilization occur in the fallopian tubes?
Definition
The ovum rapidly loses its ability to participate in development, but the zygote must be in the proper stage of development for implantation in the uterus
Term
Follicle
Definition
The oocyte and its surrounding mass of tissue
Term
Describe the Group that gave rise to the primates
Definition
About 65 million years ago a group of arboreal, nocturnal animals, called archonta underwent adaptive radiation and out of this group evolved the bats, tree shrews, and primates
Term
List the characteristics of the early primates
Definition
Grasping fingers and toes, and binocular vision
Term
Prosimians
Definition
Around 40 million years ago,the earliest primates split into two groups, one being the prosimians, they are nocturnal and eat plant material.Example: Tarsiers & Lemurs
Term
Anthropoids
Definition
also called higher primates, include monkeys, apes, and humans. Arose in Africa, gave rise to the monkeys,Old world and new world monkeys(SOuth America), About 25 million years ago anthropoids in Africa gave rise to the Old World Monkeys and to the hominids( the group leading to humans)
Term
Old World Monkeys
Definition
None of the old world monkeys have prehensile tails, and includes both have ground dwellers and arboreal species
Term
New World Monkeys
Definition
Originating in South America, are arboreal, and have prehensile tails
Term
Hominoids
Definition
Including, apes and hominids, humans and their ancestors. Evolved from Anthropoids.
Term
Characterize the living apes
Definition
Living apes include gibbon, orangutang, gorilla, and chimpanzee. Apes have larger brains than monkeys and lack a tail.
Term
Which ape is the closest living relative to humans?
Definition
Chimpanzee with 98.4% of the same nuclear DNA
Term
Origins of Bipedalism
Definition
The evolution of bipedalism marks the beginning of the hominids, but the origins of bipedalism is unknown for now. Evidence of bipedalism was found 4 million years ago
Term
Climatic Changes that favored evolutionary change in hominids
Definition
5 to 10 million years ago, the climate cooled, and the vast forests receeded, giving way to open savannahs, Bipedal hominids responded by moving out onto the savannah. The first line to adapt to this was Australopithecus
Term
Australopithecus
Definition
Walked upright, their dentition was hominid, but had small cranial capacity. Modern Humans appeared in Africa about 600K years ago
Term
Australopithecus anamensis
Definition
Slightly built individuals represent the true base of our family tree
Term
Ardipithecus ramidus
Definition
The oldest known hominid
Term
Australopithecus Africanus
Definition
Thought to be the first human ancestor, humans would have evolved from this 2 million years ago
Term
Homo habilis
Definition
Also dubbed handy man because of extensive tool use, this human is similar in build to the australopithecines, short stature
Term
Homo ergaster
Definition
This group had even larger brains and small teeth like more modern humans and is thought to be the most likely ancestor to the later species of homo
Term
Homo erectus
Definition
Without a doubt, this was an early human, nicknamed Peking man, or java man, this species survived over a million years, longer than any other species of human. Able to talk, social
Term
homo sapiens
Definition
The modern species of humans, arising from africa 600,000 years ago. We are the only surviving species of homo. Human Evolution has been characterized by increasing brain size, conceptual thought, and the development of symbolic language
Term
Identify traits of modern humans that make us unique among the animals
Definition
We attempt to modify and control the earth environment
Term
Neanderthals
Definition
Compared to humans, neanderthals were short, stalky, and powerfully built, their skulls were massive. About 130k neanderthals appeared in Europe. They did not interbreed with members of homosapiens. Common in europe and Asia 70 K years ago
Term
Cro- Magnons
Definition
Fossils of these early members of homo sapiens date back as late as 100k years ago in Europe. They appear to have completely replaced the neandethals around 34 k years ago
Term
Recently Out of Africa Model
Definition
The view of homo evolution states that homo sapiens evolved in Africa and then migrated to Europe and Asia. Fossils of Homo sapiens in Africa support this
Term
Multi Regional Hypothesis
Definition
This view of homo evolution states that the human races evolved independently from homo erectus in different parts of the world
Term
Origin of Life
Definition
Only Evolution can be tested to explain the origin of life
Term
Forming Lifes Building Blocks
Definition
The first organic molecules are believed to have formed spontaneously from building blocks subjected to lightening and UV radiation. Miller and Urey reconstructed the oxygen- free early atmosphere, and conducted experiments that confirmed these beliefs. Recent findings of even older fossils, however have refuted the findings of their experiments. Currently, a bubble model for the formation of early organic molecules is being examined
Term
How Cells Arose
Definition
Scientists now suspect that the first macromolecules were not proteins but RNA molecules
Term
The First Cells
Definition
Most scientists believe that the first cells aggregated spontaneously as microdrops that eventually were able to incorporate molecules and energy. It took millions of years for the first cell to develop
Term
Stanley Miller and Harold Urey Experiment
Definition
When subjected to levels of lightning and UV radiation, many organic building blocks formed spontaneously, called the "primordial soup", Critics of this idea have pointed out that without an ozone layer( Present only in an oxygen rich atmosphere), UV radiation would have broken down the ammonia and methane in the atmosphere. These gases contain precursors needed to make amino acids
Term
The bubble model of Louis Lerman
Definition
Volcanoes erupted under the sea, releasing gases enclosed in bubbles, The gases concentrated in bubbles reacted to produce simple organic molecules. When bubbles rose to the surface they popped releasing contents into the air, being bombarded with the suns UV rays, lightening, and other energy, The simple organic molecule reacted to form more complex organic molecules. The more complex molecules fell back into the sea as raindrops, where they could start the process over again.
Term
The Linnaean System
Definition
A much simpler system than the polynomial for the naming of organisms was developed by Carolus Linnaeus. Linnaeus assigned organisms a two- part name called a binomial. He also grouped similar organisms into higher level categories based on similar characteristics.
Term
Genus
Definition
The basic unit, used since the time of the greeks and romans. Used to classify organisms
Term
Species
Definition
A particular type of an organism
Term
Species Names
Definition
By convention, the first part of a binomial name identifies the genus to which the species belongs, and the second part distinguishes one species from others in a genus. The two names together are called the scientific name and are written in italics
Term
Higher Categoeries
Definition
The Linnaean System is a hierarchial system that uses groupings, which each one in succession smaller and more specific than the one before it. From largest to smallest, biologists use the groupings kingdom, phylum, class, order, family, genus, and species. In addition an eighth level of classification, called domains, is used.
Term
what are the 3 domains of life?
Definition
Bacteria, Archaea, & Eukarya
Term
What are the six kingdoms
Definition
Bacteria, Archaea, Protista, Plantae, fungi, animalia
Term
Phylogeny
Definition
The evolutionary history of an organism and its relationship to other species
Term
Clade
Definition
A group of organisms, related by decent, that share derived characteristics.
Term
Systematics
Definition
The study of and reconstruction of phylogenic trees. It also includes the naming and classifying of organisms
Term
Natural Selection
Definition
Unequal survival and reproduction of organisms due to environmental forces resulting in the preservation of favorable adaptations.
Term
The concept of natural Selection was refined by the observations that...
Definition
A populations growth is checked by differences in fitness ( or capacity to reproduce)
Differences among individuals determine their survival or fitness
And that some of these differences are passed from parent to offspring
Term
How do variations in natural populations occur?
Definition
Inheritance of traits, random mutations in DNA
Term
How does Natural Selection act?
Definition
it acts on individuals within a population, over generations population changes as the percentage of individuals inheriting favorable traits increases. Populations evolve, not individuals
Term
Macroevolution
Definition
Evolutionary Change of a grand scale
Term
Micro evolution
Definition
Evolutionary change at the level of a population, adaptation results from microevolutionary changes that increase likelihood of survival and reproduction of particular genetic traits within a population
Term
Jean Baptiste Lamarck
Definition
Proposed that evolution occurred by the inheritance of acquired characteristics
Term
Thomas Malthus
Definition
Wrote Essay on the Principle of Population in 1798, provided Darwin with key insight
Term
Paleontology
Definition
Studies the history and development of the earth, including that of ancient plants and animals, based on the fossil record. This includes the study of body fossils, tracks, burrows, cast off parts, fossilised faeces, palynomorphs, and chemical residue
Term
Geology
Definition
Provides information on the age of the earth
Term
Homologous Structures
Definition
Are structures with the same evolutionary origin despite differences in current function or appearances
Term
Vestigial Structures
Definition
Structures with no apparent purpose
Term
Convergent Evolution
Definition
Explains similarities arising not from a common ancestry, but as a result of natural selection of non-homologous structures that serves similar functions and resemble one another but have different internal anatomies (Analogous Structures)
Term
Embryology
Definition
Indicates Common Developmental Steps. Some Common Structures such as gills and tails form when the genes are active that direct its occurence becomes active, then when these genes are deactivated and these structures disappear
Term
Embryology
Definition
Indicates Common Developmental Steps. Some Common Structures such as gills and tails form when the genes are active that direct its occurence becomes active, then when these genes are deactivated and these structures disappear
Term
Population
Definition
A group of individuals of the same species within an ecosystem found at the same time and capable of interbreeding
Term
Evolution
Definition
The changes of allele frequencies in a gene pool over time, or the change in the genetic make up of populations over generations
Term
Hardy-Weinberg Equilibrium Model
Definition
Used to describe gene pool frequencies that under certain conditions are deemed as inherently stable. These conditions are:
No Mutations
No gene flow
Population must be very large
All mating is random
Natural Selection is not occuring
This model can be used to discover the probable genotype frequencies in a population, and to track their changes from one generation to another.
Term
Causes of Evolution
Definition
Mutations, Gene Flow, Chance Events and population size, Genetic Drift, Non random Mating, Natural Selection
Term
Mutations
Definition
The source of genetic variation because they are the source of new alleles, new varaitions on which other evolutionary process can work. Mutations happen but they are not goal directed or as a result of anticipation of external necessities
Term
Gene Flow
Definition
When individuals move from one population to another, and interbreed in the new locations, they alter the distribution of alleles among populations. The effects of gene flow are:
Gene flow carries new alleles to other populations
Gene flow prevents the development of large differences in allele frequencies and prevents speciation
Term
Chance Events and Population Size
Definition
Small populations can be exposed to chance events that may alter their genetic composition and eliminate alleles. In large populations, allele frequencies remain stable, whereas in small populations there is greater probability that a given allele with disappear in a short time.
Term
Genetic Drift
Definition
Is the change in allele frequencies in a small population as a result of chance events. Two causes of genetic drift are the population bottleneck, and the founder effect
Term
Non Random Mating
Definition
Choice of mates is not random. Non Random Mating affects the distribution of phenotypes and genotypes, and influences the direction of natural selection. Assertive mating is the preference for mates that are similar. Non random mating also takes place through competition and in some cases on sex controls mate selection.
Term
Palynomorph
Definition
Term used to describe a particle of a size between 5 and 500 micometers, found in rock deposits and composed of organic material
Term
Comparative Genomics
Definition
The study of relationships between the genomes of different species or strains
Term
Strains
Definition
The collective descendants of a common ancestor; a race, stock, line, or breed
Term
Speciation
Definition
The process of species formation, when a species splits into one or more different species
Term
Population Genetics
Definition
the study of the properties of genes in populations
Term
Gene pool
Definition
The sum of all the genes in a population, including all alleles in all individuals
Term
Stabilizing Selection
Definition
Genetic Diversity Decreases, Favors the norm, common, average traits in a population
Term
Disruptive Selection
Definition
Favors the extreme traits in a population. Variance increases as the population is divided into two distinct groups. Plays a role in speciation
Term
Directional Selection
Definition
Occurs when natural selection favors a single phenotype and therefore allele frequency continuously shifts in one direction
Term
Sexual Selection
Definition
Choosing a mate based on physical characteristics
Term
Non Random Mating
Definition
Occurs when individuals with certain genotypes mate with one another either more or less commonly than would be expected by chance
Term
Biological Species Concept
Definition
Groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups
Term
Geographic Isolation
Definition
Species occur in different areas, which are often separated by a physical barrier such as a river or mountain range
Term
Ecological Isolation
Definition
Species occur in the same area, but they occupy different habitats. Survival of hybrids is low because they are not adapted to either environment of their parents
Term
Temporal Isolation
Definition
Species reproduce in different seasons or at different times of the day
Term
Behavioral Isolation
Definition
Species differ in their mating rituals
Term
Mechanical Isolation
Definition
Structural Differences between species prevent mating
Term
Speciation two part process
Definition
First, Identical populations must converge
Second, Reproductive isolation must evolve to maintain these differences
Term
Allopatric Speciation
Definition
Geographically isolated populations become new species due to their evolving reproductive isolation
Term
Sympatric Speciation
Definition
One species splits into two at a single locality
Term
Adaptive Radiation
Definition
Cluster of species changes to occupy a series of different habitats within a region
Term
Genetic Engineering
Definition
Transferring Genes from one organism to another; major impact on medicine and agriculture
Term
Restriction Enzymes
Definition
Cleaving the DNA, Involves the use of restriction enzymes the bind specific sequences of nucleotides and split the DNA in that position. Since DNA is made up of complementary bases, both strands do not split at the same position. Instead, "Sticky Ends" result because the DNA is cleaved at an angle. These Sticky Ends can then be joined with any other complementary sequence using ligase, a sealing enzyme. Since only the ends are involved, the combining of DNA from different sources is possible
Term
The Four Stages of a Genetic Engineering Experiment
Definition
Cleaving DNA
Producing Recombinant DNA
Cloning
Screening
Term
Theory of irreversible determination
Definition
animals cells become irreversably committed after the first cell divisions
Term
Hans Spemann 1938
Definition
Cloning might be possible by removing the nucleus of an egg cell and replacing with a nucleus from another cell
Term
Neil, Campbell, and Ian
Definition
1994 and 1995 successfully cloned farm animals from advanced embroys, using cells at the G1 checkpoint to conduct transfers between cells that were at identical stages of the cell cycle
Term
Problems with Reproductive Cloning
Definition
Most embryos die in late pregnancy, large offspring syndrome
Development into adulthood goes haywire, most do not survive to live a normal life span
Term
Genomic Imprinting
Definition
Involves Chemical Changes to DNA that alters when genes are expressed without changing the sequences, Genes can be locked on or off, normal animal development depends on precise genomic imprinting
Term
Totipotent
Definition
Having the ability to form any body tissue, and even an adult animal. Embryonic Stem Cells are totipotent
Term
Embryonic Stem Cells
Definition
Cultures of cells derived from the epiblast tissue of the inner cell mass of a blastocyst or earlier morula stage embryo.
Term
Adult Stem Cells
Definition
Can be grown and transformed into specialized cells, and can be from a variety of sources including umbillical cord blood and bone marrow. These cells produce only one kind of tissue, The genes needed to produce other types of tissues are turned off
Term
Therapeutic Cloning
Definition
Using Embryonic Stem Cells to restore damaged tissue. DNA from adult cells are used to create an embro from an individual. Stem cells are then harvested from the embryo, which is then destroyed. The tissue developed from these stem cells can be injected into the damaged host. There is no issue of immunological tolerance because the donor and recipient of the stem cell therapy are the same individual
Term
Plasmids
Definition
Small, Circular, Extrachomosomal DNA molecules. They can replicate independently of the genome, and are found in numbers ranging from one per cell to hundreds per cell. Plasmids frequently carry genes for antibiotic resistance.
Term
Adenoviruses
Definition
Medium sized, non enveloped icosohedral viruses, containing double stranded DNA. Generally causing respiratory illnesses
Term
Adeno Associated Virus
Definition
Small Virus which infects humans and some other primate species. AAV is non currently known to cause disease and consequently the virus causes a very mild immune response.
Term
Polymerase Chain Reaction(PCR)
Definition
Technique to generate multiple copies of DNA.
Short sequences of DNA, called primers, are first synthesized
The primer sequences occur on either side of the DNA region to be amplified
The PCR technique is a way to generate a lot of DNA of interest quickly, rather than rely on bacteria to produce copies
Term
Working with DNA: PCR
Definition
The DNA target sequence, primers, polymerase, and a supply of all four nucleotides are first combined in a solution; the solution is heated to about 95 degrees celcius, The polymerase used is a special heat resistant variety called taq polymerase. The heat causes The DNA to denature into single strands
Term
STEPS of PCR
Definition
Denaturation; Heating the reaction
Primer Annealling; Lowering the reaction temperature, allowing annealling of the primers to the single stranded DNA template
Primer Extention; DNA polymerase synthesizes a new DNA strand complementary to the DNA template stand by adding dNTPs that are complementary to the template in a 5' to 3' direction
Term
cDNA
Definition
Complementary DNA, an intron free version of a eukaryotic gene for genetic engineering
Term
Restriction Enzymes to produce DNA
Definition
Restriction Enzyme cleaves the DNA, DNA from another source cut from the same restriction enzyme is added, DNA ligase joins the strands
Term
DNA fingerprinting
Definition
uses probes on DNA samples that have been cut with the same restriction endonucleases. The probes are unique DNA sequences found in non-coding regions of human DNA that are highly variable among individuals
Term
Cleaving
Definition
Enzymes cut the source DNA at specific sites, cleaving the two strands short distances apart
Term
Produce Recombinant DNA
Definition
A circular plasmid cut with the same enzyme is combined with the fragments of source DNA
Term
Cloning
Definition
A variety of recombinant plasmids are produced. Plasmids are mixed with the bacterial cells. Some cells take up plasmids, and some do not. Each cell reproduces and forms a clone of bacterial cells, each clone containing one type of plasmid. All the cells constitute a clone library
Term
Screening
Definition
Bacterial Cells that did not take up the plasmid are screened out using an antibiotic for which the plasmid contains a resistant gene. Then those plasmid containing cells that possess the recombinant DNA are identified. Lastly, those cells containing the gene of interest are found using a probe sequence complementary to that gene
Term
Gene Transfer Therapy
Definition
Involves transferring healthy versions of a gene into cells that lack them
Term
Beneficence Principle
Definition
Ethicists use this to weigh the risks verus the benefits when making decisions about potential therapy
Term
Respect for Persons Principle
Definition
Ethicists respect the right of persons affected by the procedure to make their own informed decisions
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