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199 Cards in this Set
- Front
- Back
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what are three things plant cells have that animal cells dont?
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chloroplast, vacuole, cell wall
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which three places in a plant cell contain genetic information?
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chloroplast, nucleous, and mitchondria
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what is the site of genetic processes?
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cytoplasm
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what is DNA wrapped around?
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histome chords
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what connects sister chromatids?
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centromere
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What happens in meiotic prophase 1: leptonema?
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condensation of chromosomes, replicated chromosomes visible, nucleolus visible at times
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What happens in meiotic prophase 1: zygonema?
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homologous chromosomes pair up and gather together
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What happens in meiotic prophase 1: pachynema?
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crossing over occurs, homologous chromosomes are fully paired
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What happens in meiotic prophase 1: diplonema?
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homologous chromosomes repel eachother, chiasmata become visible
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What happens in meiotic prophase 1: diakenisis?
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chromosomes continue to shorten and thicken, nuclear membranes dissolve, mictrotubules attach to kinetochore
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what are chiasmata?
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the physical manifestation sites of crossing over
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what is a dyad?
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when a cell does not split during meiosis after telophase 1
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how many nuclei does a megaspore mother cell contain?
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8
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how many nuclei does a microspore mother cell contain?
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3; generative cells and nucleus
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what are the four cell types in a megaspore mother cell?
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egg, antipodals, polar nuclei, and synergids
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sperm nucleus (n) + egg nucleus (n) =
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embryo (2n)
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sperm nucleus (n) + secondary endosperm (2n) =
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endosperm (3n)
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corn pericarp is genetically ---.
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maternal
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what are the two layers of a corn kernel that is 3n?
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aleurone and endosperm
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what is endoreduplication?
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DNA replication without division
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what is a locus?
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a location on a chromosome defined genetically or by sequence
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what is a monohybrid?
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a cross in which one gene is segregated
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what is homologous?
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containing 2 of the same alleles at a locus
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what is heterozygous?
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2 different alleles at a locus
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what is a self cross?
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fertilization of egg and sperm of one individual
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what is a sib cross?
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a cross made between 2 related offspring
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what is a backcross?
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a cross made between an offspring and the parent
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what is a testcross?
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a cross made with a homozygous recessive individual
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what is mendel's first law?
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in a heterozygote, one allele may conceal the existence of another
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what is medel's second law?
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in a heterozygote, two alleles seperate from eachother in the formation of a gamete
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what is the ratio of a dihybrid cross?
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9:3:3:1
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what is mendel's third law?
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independent assortment: alleles of different genes segregate seperately from eachother
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what is the multiplicative rule?
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the probability of evens a and b is the product of independent probabilities. P(a)xP(b)
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what is the additive rule?
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the probability of events a or b is the sum of independent probabilities minue the probalilty of both a and b. P(a)+P(b)- [ P(a)xP(b)]
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what is chiasma?
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the x shaped microscopically visible region representing homologous chromatids that have crossed over
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what is chromatid?
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in meiosis or mitosis, one of the two identical strands resulting from self-duplication of a chromosome
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what is chromatin?
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the complex of DNA, RNA, histones, and non-histone proteins that make up uncoiled chromosomes
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what is a dihybrid?
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produced by parents differing for two genes that control two different traits
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what is heterochromatin?
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nontranscribed eukaryotic chromatin that is so highly compact it is visible with a light microscope during interphase; thought to be devoid of structural genes
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what is a kinetochore?
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a proteinaceous structure associated with the centromere of a chromosome; the point at which microtubules attach to move the chromosome through the division process
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what is segretation?
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the seperation of paternal and maternal chromosomes from eachother at meiosis; OR the occurance of difference phenotypes among offspring resulting from parental allele seperation
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what is incomplete penetrance?
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an individual has the appropriate genotype to show a phenotype, but appears normal
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what is expressivity?
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individuals with the same genotype show varying degrees of phenotype
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what is epistasis?
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the interaction of genes to produce a phenotype
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what is pleiotropy?
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effect of a gene on multiple traits
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what is coupling phase?
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alleles of a certain type (dominant, favorable) are present on the same parental chromosome
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what is repulsion phase?
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alleles of a certain type are (dominant, favorable) are present on the same parental chromosomes
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what is a parental gamete?
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gamete with the parental allelic constitution
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what is a recombinant gamete?
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a gamete with the non parental allelic constitution
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what are additive allelic effects?
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genetic factors that raise or lower the value of a phenotype on a linear scale of measurement
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what is an allele?
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an alternate form of a gene
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what is an allopolyploid?
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a polyploid having chromosome sets from different species; a polyploid containing genetically different chromosome sets derived from two or more species
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what is an autopolyploid?
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a polyploid that has multiple and identical or nearly identical sets of chromosomes (genomes). A polyploidy species with genomes derived from the same original species
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what is a backcross?
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a cross of an F1 to either parent used to generate it
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what is a bivalent?
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a pair of synapsed or associated homologous chromosomes that have undergone the duplication process to form a group of four chromatids
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what is a centromere?
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a region on the chromosome that joins two sister chromatid.
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what is a chiasma?
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the X-shaped, microscopically visible region representing homologous chromatids that have exchanged genetic material through crossing over during meiosis
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what is chromosome banding?
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staining of chromosomes in such a way that light and dark areas occur along the length of the chromosomes. Lateral comparisons identify pairs.
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what is chromatiD?
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in meiosis or mitosis, one of the two identical strands resulting from self-duplication.
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what is chromatiN?
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the complex of DNA, RNA, histones, and nonhistone proteins that make up uncoiled chromosomes characteristic of the eukaryotic interphase nucleus
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what is co-dominance?
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condition where the phenotypic effects of a gene's alleles are fully and simultaneously expressed in the heterozygote
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what is the coefficient of coincidence?
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the ratio of the observed frequency of double cross overs to the expected frequency, where the expected frequency is calculated by assuming that the two crossover events occur independently of each other.
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what is coupling phase?
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alleles of the same type (dominant) are present on the same parental chromosome
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what is the complementation test?
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introduction of two recessive mutations into the same cell to determine whether they are alleles of the same gene; whether they affect the same genetic function.
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in the complementation test, what will the genotype exhibit if the mutation is allelic? non-allelic?
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the mutant phenotype; the wild phenotype
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what is diakinesis?
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a stage of meiosis just before metaphase I in which the bivalents are shortened and thickened
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what is a dihybrid?
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produced by parents differing for two genes that control two different traits
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what is a diploid?
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an organism or ell with two sets of chromosomes (2n) or two genomes
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what is dominant?
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condition where one member of an allele pair is manifested to the exclusion of the other; the phenotype of the heterozygote class is the same as the homozygote class.
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what is double fertilization?
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the fusion of egg and sperm resulting in a zygote and the simultaneous fusion of the second male gamete with the polar nuclei, resulting in the 3n endosperm
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what is endoreduplication?
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DNA replication without division
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what is epistasis?
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the interaction of genes to produce a phenotype; one gene alters the expression of another that is independently inherited
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what is a euploid?
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an organism or cell having a chromosome number that is an exact multiple on the haploid number. Terms used to identify different levels in an a euploid are diploid, triploid, etc.
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what is expressivity?
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the degree of expression of a trait controlled by a gene. a particular gene may produce degrees of expression in different individual of the same genotype.
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what is F1?
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the first filial generation
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what is a genetic map?
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a diagram of a chromosome with distances based on recombination frequencies. Units in centiMorgans.
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what is a genotype?
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the genetic makeup of an organism
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what is a haploid?
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an organism or cell having only one complete set of chromosomes or one genome; gametic chromosome number
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what is heterochromatin?
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nontranscribed eukaryotic chromatin that is so highly compact it is visible with a light microscope during interphase; though to be devoid of structural genes
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what is heterozygous?
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individual containing two different alleles at a locus
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what are homEologous chromosomes?
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partially indentical chromosomes but the don't pair during meiosis
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what are homologous chromosomes?
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chromosomes that pair during meisis. Chromosomes that are identical with respect to their genetic loci and centromere placement
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what is homozygous?
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individual containing two of the same allele as a locus.
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what is incomplete dominance?
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type of inheritance where F1 hybrids (heterozygotes) have an appearance that is intermediate between the phenotypes of the parental varieties.
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what is incomplete penetrance?
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an individual has the appropriate genotype to show a particular phenotype, but appears normal
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what is independent assortment?
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the random distribution of alleles to the gametes that occurs when geners are located in different chromosomes; the alleles of different genes assort randomly
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what is in situ hybridization?
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a method for determining the location of specific DNA sequences in chromosomes by hybridizing labeled DNA or RNA to denature DNA in chromosomes preparations and visualizing the hybridized probe bu autoradiography for flurescence in microscopy.
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what is interference?
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crossing over at one point that reduces the chance of another crossover nearby; detected by studying the pattern of crossing over with three or more linked genes.
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what is karyotype?
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a method of organizing the chromosomes of a cell in relation to number, size, and type
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what is a kinetochore?
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a proteinaceous structure associated with the centromere of chromosomes; where microtubules attach for division.
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what is linkage?
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a relationship among genes in the same chromosome. Such genes tend to be inherited together.
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what is a locus?
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a fixed position on a chromosome defined genetically or by sequence
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what is megasporogenesis?
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the formation of a haploid spore that develops into a female gametophyte
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what is microsporogenesis?
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the formation of a spore that develops into a male gametophyte
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what is a metacentric chromosome?
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a chromosome with a centrally located centromere, producing arms of equal length
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what is a monohybrid?
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cross between two parents who differ at a single gene locus that has two alleles.
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what is nullisomic?
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an otherwise diploid organism lacking both members of a chromosome pair (2n-2)
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what is monosomic?
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a diploid organism lacking one chromosome of its proper complement (2n-1); an aneuploid.
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what is paracentric inversion?
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an inversion including the centromere, hence involving both arms of a chromosome
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what is phenotype?
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the physical or observable characteristics of an organism
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what is ploidy?
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term referring to the basic chromosome set or to multiples of that set
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what is recessive?
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condition when one member of an allelic pair lacks the ability to manifest itself in the phenotype when the other or dominant member is present
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what is recombination?
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the production of gene combinations that are not found in the parents through the assortment of non homologous chromosomes and crossing-over during meiosis.
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For linked genes, the frequency of recombination can be used to estimate the ---.
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genetic map
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what is the repulsion phase?
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alleles of a certain type (dominant) are present on the opposite parental chromosomes.
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what is segregation?
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1. the separation of paternal and maternal chromosomes from each other at meiosis; 2. the occurence of different phenotypes among offspring
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what is a submetacentric chromosome?
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a chromosome with the centromere placed so that one arm of the chromosome is slightly longer than the other
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what is a telocentric chromosome?
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a chromosome in which the centromere is located at the end of the chromosome
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what is a test cross?
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a backcross to the recessive parental type or a cross between genetically unknown individuals with a fullly recessive tester to determine whether an individual in question is heterozygous or homozygous for a certain allele.
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what is tetrasomic?
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pertaining to a nucleus or an organism with four members of one of its chromosomes whereas the remainder of its chromosome complement is diploid (2n+2)
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what is translocation?
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change in position of a segment of a chromosome to another part of the same chromosome or a different chromosome
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what is trisomic?
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an otherwise diploid cell or organism that has an extra chromosome of one pair (2n +1)
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what is univalent?
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an unpaired chromosome at meiosis
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what are the three plant specific cell structures?
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chloroplast, vacuole, and cell wall
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what are the three organelles that contain genetic information in a plant?
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nucleus, chloroplast, mitochondria
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what happens in the G1 phase of the cell lifecycle?
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cells grow and carry out normal metabolism
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what happens in the S phase of the cell lifecycle?
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DNA replicates and chromosomes duplicate
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what happens in the G2 phase of the cell life cycle?
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the cell grows and prepares for mitosis
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if corn has 10 pairs of chromosomes, how many chromosomes and chromatids does it have in the G1 phase?
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20, 20
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if corn has 10 pairs of chromosomes, how many chromosomes and chromatids does it have in the G2 phase?
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20, 40
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if corn has 10 pairs of chromosomes, how many chromosomes and chromatids does it have in the S phase?
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20, 20-40
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what happens in prophase of mitosis?
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condensation of nucleus, nucleolus disperses
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what happens in early metaphase of mitosis?
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the nuclear envelope disperses, chromosomes move to metaphase plate.
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what happens in metaphase of mitosis?
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chromosomes align at the metaphase plate
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what happens in anaphase of mitosis?
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chromatids seperate and begin moving toward poles
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what happens in telophase of mitosis?
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chromatids reach poles, nuclear envelope reforms
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what happens in cytokinesis?
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cell membrane and wall separate daughter cells
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corn has 10 chromosome pairs. How many chromosomes and chromatids are present in metaphase of mitosis?
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20, 40
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corn has 10 chromosome pairs. How many chromosomes and chromatids are present in each newly divided cell following mitosis??
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20, 20
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how many kinetochores are aligned on the metaphase plate at mitosis for corn, which has 10 chromosome pairs?
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20, one for each chromosome
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what is a acronym for the stages of meiotic prophase?
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little zebras play daily double
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what happens in leptonema?
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replicated chromosomes become visible
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what happens in zygonema?
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homologous chromosomes pair
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what happens in pachynema?
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crossing over occurs. recombination.
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what happens in diplonema?
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homologous chromosomes begin to repel each other. Chromatids and chiasmata become visible.
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what happens in diakinesis?
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chromosomes continue to shorten and thicken. Nuclear membranes disappear. Chiasmata terminalize
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which meiosis cycle is called 'reductional division'?
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meiosis 1
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which meiosis cycle is called 'equational division'?
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meiosis 2
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what is a dyad stage?
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where cytokinesis doesnt occur in meiosis 1
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in corn with 10 pairs, how many chromosomes and chromatids are in mitotic metaphase?
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20, 40
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in corn with 10 pairs, how many chromosomes and chromatids are in meiotic metaphase 1?
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20, 40
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in corn with 10 pairs, how many chromosomes and chromatids are in meiotic metaphase 2
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10, 20
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in corn with 10 pairs, how many chromosomes and chromatids are in mitotic telophase?
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20, 20
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in corn with 10 pairs, how many chromosomes and chromatids are in meiotic telophase 1?
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10, 20
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in corn with 10 pairs, how many chromosomes and chromatids are in meiotic telophase 2?
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10, 10
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what are the layers (outside to inside) of a corn kernal?
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pericarp, aleurone, endosperm, embryo
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maternal aa, paternal A. what is the genotype of a pericarp?
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aa
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maternal aa, paternal A. what is the genotype of the aleurone?
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aaA
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maternal aa, paternal A. what is the genotype of the endosperm?
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aaA
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maternal aa, paternal A. what is the genotype of the embryo?
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aA
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what are a few examples of endoreduplication?
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monocot endosperm, cotyledons, leaf, root.
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what is the purpose of endoreduplication?
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storage (seeds), or to facilitate sufficient transcription of certain genes
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what is the principle of dominance?
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in a heterozygote, one allele may conceal the presence of another
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what is the principle of segregation?
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in a heterozygote, two alleles segregate from each other during the formation of gametes
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an ear is segregating 3/4 yellow and 1/4 white. what is the likely genotype of the parents?
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Yy
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an ear is segregating 3/4 yellow and 1/4 white. what are possible genotypes of the grandparents of those seeds?
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YY, Yy, yy
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an ear is segregating 3/4 yellow and 1/4 white. what would be the frequency of yellow and white seeds if the parent of this ear had been crossed to a yy genotype?
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1/2 yellow, 1/2 white
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what is the principle of independent assortment?
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the alleles of different genes segregate independently of each other.
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what is the multiplicative rule?
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the probability of events a AND b is the product of their independent probabilties
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what is the additive rule?
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the probability of events a OR b is the sum of the independent probabilities minus the probability of both
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what is the equation for chi-squared testing?
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chi-squared = E (observed-expected)^2/ expected
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in wheat, functional proteins at both Pina and Pinb are required to make --- grain.
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soft
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what are two ways to determine allelism for a lethal mutation?
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1. self and cross normal plants from the mutant and tester rows.
2. make multiple crosses of normal plants between the mutant and tester row |
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what is the equation for calculating linkage?
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recombinants/total = frequency of recombination
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what is the equation for parental gamete frequencies?
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(1-r)/2
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what is the equation for recombinant gamete frequencies?
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r/2
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what is the equation for interference?
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1-c = interference
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what is the equation for the coefficient of coincidence?
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observed DCO/ Expected DCO = c
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what is the equation for genetic distance (r)?
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recominants/total = r
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recombination is infrequent near the heterochromatic ---- and frequent in the gene-rich regions distal to the ----.
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centromere for both
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the dark area in chromosome banding typically indicate the ---.
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centromere
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recombination occurs in ---, not in heterochromatin.
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genes
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what is propidium iodide?
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stain for protein
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chromosome banding is more/less specific than in situ hybridization.
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more
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the suffix -ploid refers to what?
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sets of chromosomes
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the suffix -somic refers to what?
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number of chromosomes
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translocations result in semisterility in ---.
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heterozygotes
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inversions are --- in heterozygotes.
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paracentric
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what is the equation for genetic distance (r)?
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recominants/total = r
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recombination is infrequent near the heterochromatic ---- and frequent in the gene-rich regions distal to the ----.
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centromere for both
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the dark area in chromosome banding typically indicate the ---.
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centromere
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recombination occurs in ---, not in heterochromatin.
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genes
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what is propidium iodide?
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stain for protein
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chromosome banding is more/less specific than in situ hybridization.
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more
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the suffix -ploid refers to what?
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sets of chromosomes
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the suffix -somic refers to what?
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number of chromosomes
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translocations result in semisterility in ---.
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heterozygotes
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inversions are ---.
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paracentric
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polysomic inheritance has genes in different ratios because the same two chromosomes are not always -- to eachother.
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next
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what are two things that can lead to unreduced games and polyploidy?
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tripolar spindles and parallel spindle mutations
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most aneuploidy results in --- at the gametic stage in plants.
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gametic
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if wheat has 42 chromosomes, how many does monosomic wheat have?
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42
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which corn has 20 chromosomes, how many does trisomic corn have?
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21
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if corn has 20 chromosomes, how many does triploid corn have?
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30
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if wheat has 42 chromosomes, how many does nullisomic wheat have?
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40
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heterozygotes that translate adjacenty are --.
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sterile.
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what is an indel?
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an insertion or deletion
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what is a pericentric inversion?
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one that included the centromere, alters arm ratios, and does NOT effect fertility
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what is paracentric inversion?
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one that does not include the centromere, where heterozygotes have reduced fertility
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