General Biology Chapter 15

General Biology The Chromosome Basis of Inheritance 

46 cards   |   Total Attempts: 182
  

Cards In This Set

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The chromosome theory of inheritance states:
– Mendelian genes have specific loci (positions)on chromosomes– Chromosomes undergo segregation andindependent assortment
The behavior of chromosomes during meiosiscan account for Mendel’s______________ and__________
Law of segregation and Independent assortment
Which characteristics make fruit flies aconvenient organism for genetic studies?
– They produce many offspring– A generation can be bred every two weeks– They have only four pairs of chromosomes
What is wild type?
Normal, phenotypes that are common
In humans and some other animals, there is achromosomal basis of ____________
Sex determination
In humans and other mammals, there are twovarieties of sex chromosomes:
A larger X chromosome and a smaller Y chromosome
Only the ends of the _____ chromosome haveregions that are homologous with correspondingregions of the ___ chromosome
Y, X
The______ gene on the Y chromosome codes fora protein that directs the development of maleanatomical features
SRY
A gene that is located on either sex chromosomeis called a__________
Sex linked gene
Genes on the X chromosome are called _________
X-linked
Genes on the Y chromosome are called_____________
Y-linked genes; there are few of these
A _____ frequency of recombination is observedfor any two genes on different chromosomes
50%
__________ have genes for many characters unrelated to sex, whereas the _________ mainly encodes genes relatedto sex determination
X chromosomeY chromosome
For a recessive X-linked trait to be expressed:
A female needs two copies of the allele(homozygous)– A male needs only one copy of the allele(hemizygous)
In _____________, one of the two Xchromosomes in each cell is randomlyinactivated during embryonic development
Mammalian females