bio 1001 ch 10

what are genes
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Terms in this set (51)
what are genes
sequences of nucleotides at specific locations on chromosomes
whats inheritance
the process by which the characteristics are passed on to offspring
whats a gene
a unit of DNA that encodes information needed to produce proteins, cells, and entire organisms
whats a locus
the location of a gene on a chromosome
what type of cells of organisms have chromosomes occur in pairs
ordinary body cells(not sperm of eggs)
human cells contain how many chromosomes
46 chromosomes, 23 pairs
what are autosomes
non-sex chromosomes
what are homologous chromosomes
chromosomes that carry the same kinds of genes for the same characteristics
what are alternative versions of genes found at the same gene locus?
alleles
how are alleles formed?
mutations
IF a mutation occurs in _______, the cells that become sperm of eggs, then the mutation can be passed on from parent to offspringgameteseach cell carries how many allelels per characteristic?2 alleles per characteristic, one on each o the two homologous chromosomesIf both homologous chromosomes carry the same allele(gene form) at a given gene locus, the organism is ___________at that locus.homozygousif two homologous chromosomes carry different alleles at a given locus, the organism is ____________ at that locus, also called__________heterozygous ...also called hybriddiscovered patterns of inheritance and many essential facts about genes, alleles, and the distribution of alles in gametes during sexual reproduction. -he chose edible pea plants for his experiments -Allowed him to see patterns in the way plant characteristics were inheritedGregor Mendel (austrian monk in a monastery in late 1800's)why did mendel choose pea plants?it had stames(produce sperm) and carpels(produce eggs) so it could have sex with itself and prevent entry of pollen from another pea planthow do pea plants naturally self-fertilizebecause of their structuremendel used another pea plants pollen to fertilze another pea plant. this was called what?cross-fertilizationwhat was the key to mendels successhe chose a simple experimental designwhat are individual characteristics?traitsHow did mendel analyze inheritence in pea plants?by following inheritance of traits for several generations, counting numbers of offspring w/ ea. type of trait.plants that are homozygous for a characteristic are described astrue-breedinghow are single traits inheritedpea plants that are homozygous for a particular characteristic always produce the same phenotypewhat is the mating of pollen and eggs(from same or different parents)Genetic crosswhats the particular combination of the two alleles carried by an individual calledgenotypewhats the physical expression of the genotype?phenotypeis phenotype determined by genotype or is genotype dtermined by phenotypeobviously the phenotype is determined by genotype. the phenotype simply physically shows the data from what the genotype gave it.what type of method predicts offspring genotypes and phenotypes from combinations of parental gametes?The Punnett square methodwhat is used to deduce whether an oganism with a dominant phenotype is homozygous or heterozygoustest crosshow is sex dtermined in offspringmammals have a set of sex chromosomes that dictate genderwhats the combination of sex chromosomes that females have?two X chromosomeswhats the combination of sex chromosomes that males have?males have an X chromosome and a Y chromosomenon sex chromosomes that occur in iddentical pairs are called whatautosomesif a female egg is fertalized with a Y chromosome what gender results...also what are the results for an X chromosomefertilization with a Y - male results(XY) fertilization with an X - female results(XX)do all traits follow simple Mendelian rules of inheritance?NOT/F not all traits are completelyk controlled by a single geneTrueT/F A trait may not be completely dominant to anotherTrueWhen the heterozygous phenotype is intermediate between the two homozygous phenotypes, the pattern of inheritance is called what?incomplete dominancewhats human hair texture an example of?incomplete dominancean individual may have ______ different gene alleles A species may have _______ for a given characteristicmay have at most two different gene alleles may have multiple alleles for a given characteristicWhen heterozygotes express the phenotypes of both of the homozygotes, the pattern of inheritance is called whatcodominance...ex: AB type bloodpeople make antibodies to the type of glycoproteins they_____.they lack.for the bloodtypes, what are the antibodies to them? type A blood type B blood type o blood type AB bloodtype A blood makes B antibodies type B blood makes A antibodies type o blood makes A & B antibodies type AB blood doesnt make antibodiesthese cause red blood cells that bear foreign glycoproteins to clump together and ruptureantibodies cause thiswhich type of blood doesnt have any sugars attached to ittype oThe ___________ influences the expression of genesThe environmentsome human genetic disorders are linked to whatthey are sex-linked the X chromosome contains many genes that have no counterpart ont he Y chromosomesex-linked diseases, such as hemophilia, tend to occur more often in (male or female)males.The incorrect separation of chromosomes in meiosis is known as:nondisjunctionthis causes gametes to have too many and too few chromosomesnondisjunctionTrisomy 21 ( has 3 copies of chromosome 21) is also known asDown syndrome.