Bio Test 5

clairebear2018's version from 2018-05-03 13:56

Section 1

Question Answer
The continuity of life is based on the reproduction of cellscell division
Cell division is an integral part of the _____, the life of a cell from formation to its own divisioncell cycle
All the DNA in a cell constitutes the cell’sgenome
DNA molecules in a cell are packaged into chromosomes
Eukaryotic chromosomes consist of ______, a complex of DNA and protein that condenses during cell divisionchromatin
Somatic Cells(nonreproductive cells) have two sets of chromosomes
Gametes(reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells
Each duplicated chromosome has two ______ (joined copies of the original chromosome), attached along their lengths by cohesinssister chromatids
The _____ is the narrow “waist” of the duplicated chromosome, where the two chromatids are most closely attachedcentromere
Mitosisthe division of the genetic material in the nucleus
Cytokenesisthe division of the cytoplasm
Mitosis is conventionally broken down into five stagesprophase, prometaphase, metaphase, anaphase, telophase
The _____ is a structure made of microtubules that controls chromosome movement during mitosismitotic spindle
In animal cells, assembly of spindle microtubules begins in the _____, the microtubule-organizing centercentrosome
Kinetochoresare protein complexes associated with centromeres
At metaphase, the chromosomes are all lined up at the _____, a plane midway between the spindle’s two polesmetaphase plate
In animal cells, cytokinesis occurs by a process known as _____, forming a _____cleavage ; cleavage furrow
In plant cells, a _____ forms during cytokinesiscell plate
Prokaryotes (bacteria and archaea) reproduce by a type of cell division called binary fission

Section 2

Question Answer
In binary fission, the chromosome replicates (beginning at the _____), and the two daughter chromosomes actively move apartorigin of replication
The sequential events of the cell cycle are directed by a distinct _____, which is similar to a clockcell cycle control system
The clock has specific ____ where the cell cycle stops until a go-ahead signal is receivedcheckpoints
Two types of regulatory proteins are involved in cell cycle controlcyclins ; cyclin-dependent kinases
Maturation-Promoting Factoris a cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into the M phase
If the cell does not receive the go-ahead signal, it will exit the cycle, switching into a nondividing state called theG0 Phase
Growth Factorsare released by certain cells and stimulate other cells to divide
Cells that acquire the ability to divide indefinitely are undergoingtransformation
If abnormal cells remain only at the original site, the lump is called abenign tumor
____ invade surrounding tissues and can undergo _____, the spread of cancer cells to other parts of the body, where they may form additional tumorsmalignant tumors ; metastasis
Heredity is the transmission of traits from one generation to the next
Variationis demonstrated by the differences in appearance that offspring show from parents and siblings
Geneticsis the scientific study of heredity and variation
Genesare the units of heredity and are made up of segments of DNA
A gene’s specific position along a chromosome is called itslocus
ASexual Reproductiona single individual passes all of its genes to its offspring without the fusion of gametes
Cloneis a group of genetically identical individuals from the same parent
Sexual Reproductiontwo parents give rise to offspring that have unique combinations of genes inherited from the two parents

Section 3

Question Answer
_____ is the union of gametes (the sperm and the egg)fertilization
The fertilized egg is called a _____ and has one set of chromosomes from each parentzygote
Meiosis takes place in two consecutive cell divisions, called _____ and _____meiosis I ; meiosis II
In early prophase I, each chromosome pairs with its homolog and _____ occurscrossing over
X-shaped regions called _____ are sites of crossoverschiasmata
A zipper-like structure called the _____ holds the homologs together tightlysynaptonemal complex
During _____, DNA breaks are repaired, joining DNA from one nonsister chromatid to the corresponding segment of anothersynapsis
Crossing over produces ______, which combine DNA inherited from each parentrecombinant chromosomes
A heritable feature that varies among individuals (such as flower color) is called acharacter
Each variant for a character, such as purple or white color for flowers, is called atrait
True Breedingplants that produce offspring of the same variety when they self-pollinate
In a typical experiment, Mendel mated two contrasting, true-breeding varieties, a process calledhybridization
Possible combinations of sperm and egg can be shown using a _____, a capital letter represents a dominant allele, and a lowercase letter represents a recessive allelepunnett square
An organism with two identical alleles for a character is called a _____homozygote
To determine the genotype we can carry out a _____, breeding the mystery individual with a homozygous recessive individualtestcross
The F1 offspring produced in this cross were _____, heterozygous for one charactermonohybrids
Crossing two true-breeding parents differing in two characters produces _____ in the F1 generation, heterozygous for both charactersdihybrids
Using a dihybrid cross, Mendel developed the _____, it states that each pair of alleles segregates independently of any other pair of alleles during gamete formationlaw of independent assortment
The _____ states that the probability that two or more independent events will occur together is the product of their individual probabilitiesmultiplication rule

Section 4

Question Answer
The _____ states that the probability that any one of two or more mutually exclusive events will occur is calculated by adding together their individual probabilitiesaddition rule
Occurs when phenotypes of the heterozygote and dominant homozygote are identicalcomplete dominence
In _____, the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varietiesincomplete dominence
In _____, two dominant alleles affect the phenotype in separate, distinguishable wayscodominence
Tay-Sache Diseasea dysfunctional enzyme causes an accumulation of lipids in the brain
Most genes have multiple phenotypic effects, a property calledpleiotropy
In _____, expression of a gene at one locus alters the phenotypic expression of a gene at a second locusepistasis
Quantitative charactersare those that vary in the population along a continuum
Quantitative variation usually indicates _____, an additive effect of two or more genes on a single phenotypepolygenic inheritance
Traits that depend on multiple genes combined with environmental influences are calledmultifactorial
A _____ is a family tree that describes the interrelationships of parents and children across generationspedigree
Carriersheterozygous individuals who carry the recessive allele but are phenotypically normal
Cystic fibrosisthe most common lethal genetic disease in the United States, striking one out of every 2,500 people of European descent
Huntington’s diseasea degenerative disease of the nervous system
In _____, the liquid that bathes the fetus is removed and testedamniocentesis
In _____, a sample of the placenta is removed and testedchorionic villus sampling (cvs)
A gene that is located on either sex chromosome is called asex-linked gene
Genes on the X chromosome are called ____, the human X chromosome contains about 1,100 genesx-linked genes
Genes that are located on the same chromosome tend to be inherited together and are calledlinked genes
Genetic Recombinationthe production of offspring with combinations of traits differing from either parent

Section 5

Question Answer
Offspring with a phenotype matching one of the parental (P) phenotypes are calledparental types
Offspring with nonparental phenotypes (new combinations of traits) are called ______, or ______recombinant types ; recombinants
Alfred Sturtevant, one of Morgan’s students, constructed a ______, an ordered list of the genetic loci along a particular chromosomegenetic map
Distances between genes can be expressed as map _____, one _____ represents a 1% recombination frequencymap unit
In _____, pairs of homologous chromosomes do not separate normally during meiosisnondisjunction
Aneuploidy results from the fertilization of gametes in which nondisjunction occurred
Monosomyhas only one chromosome of a particular pair
Trisomyhas three chromosomes of a particular pair
Polyploidyis a condition in which an organism has more than two complete sets of chromosomes
Triploidy(3n) is three sets of chromosomes
Tetraploidy(4n) is four sets of chromosomes
Deletionremoves a chromosomal fragment
Duplicationrepeats a segment
Inversionreverses orientation of a segment within a chromosome
Translocationmoves a segment from one chromosome to another
Down syndromean aneuploid condition that results from three copies of chromosome 21

Section 6

Question Answer
Chromatingranulated uncondensed DNA
Chromosomecondensed DNA molecule
Somatic Cellnormal body cell (2n)
Gametesex cell (n)
Mitosiscell division of somatic cells
Genomecomplete genetic makeup of a cell
Sister Chromatidone half of a chromosome pair
An example of asexual reproduction seen in unicellular organisms isbinary fission
The process of cell division that produces 4 haploid gametes is calledmeiosis
The 23 pairs of inherited chromosomes, one maternal and one paternal are calledhomologs
An orderly arranged display of the 23 pairs of chromosomes is called akaryotype
Differences found meiosis I and not in mitosis include the synapse of ______ and _____tetrads ; crossing over
In humans, chromosomes pairs 1-22 are ______, while pair 23 are ______autosomes ; sex chromosomes
Mendels study of hereditary and inherited variation is known asgenetics
The set of chromosomes you inherit is your _____, while the expression of these genes is your ______genotype ; phenotype
Traits that are fully expressed are called _____ , while traits that are masked are called _____dominant ; recessive
Traits that are a blend of dominant and recessive genes exhibitincomplete dominance
When two different alleles each effect the phenotype (MN or AB) it is calledcodominance
The ABO blood group in humans that have 3 possible alleles is an example ofmultiple alleles