Chapter 13: The Chromosomal Basis of Inheritance, and Human Genetics Flashcards
Who
1.first suggested the central role of chromosomes
2. authored one of the scientific papers announcing rediscovery of Mendel’s work
Carl Correns 1900
Who
1. had the chromosomal theory of inheritance
2. Based on observations that similar chromosomes paired with one another during meiosis
Walter Sutton 1902
T.H Morgan worked with fruit fly called ______ ________
drosophila melanogaster
T.H Morgan discovered a mutant male fly with _____ eyes instead of red
white
When T.H Morgan crossed the mutant white eye male fly with a normal red-eyed female what was the progeny of all F1?
red eye= dominant trait
When Morgan crossed the F1 females with the F1 males, the F2 generations contained what color eyed flies?
Both red and white
When F1 females in F1 males crossed in Morgan’s experiment, in the F2 generation all the white-eyed flies were _____
male
T.H morgan discovered with the fruit flies that the eye color gene resides on the __ chromosome
X
When Morgan testcrossed F1 females with a white eyed male it showed viability of white-eyed ______
females
Traits determined by sex chromosome genes are _____-______
sex-linked
____ chromosomes are a pair dissimilar chromosomes that still pair during meiosis and mitosis
sex
Sex determination in Drosophila is based on the number of ____ chromosomes
X
T or F: Sex chromosomes varies across organisms
True
In human sex determination is based on the presence of a ___ chromosome in humans
Y
In birds, the male has two __ chromosomes and females are ZW
ZZ
Some insects are either XX (female) or X__ in males
O (O indicating absence of a chromosome
In Honeybees, females are ______ and males are _______
diploid, haploid
Y chromosomes are highly ______
condensed
_______ are non-sex chromsomes
autosomes
_____ genes from Y chromosome are expressed
few
Recessive alleles on X chromosome have no active partner on ___
Y
______ _______ ensures equal expression of genes from sex chromosomes even though number of chromosomes is different between sexes
dosage compensation
In mammalian female cells, 1 X chromosome is randomly inactivated and is highly condensed into a ______ body
Barr
Females heterozygous for genes on the X chromosome are _____ ______
genetic mosaics
What are the chromosome theory exceptions?
Mitochondria and Chloroplasts contain genes
T or F: Traits controlled by Mitochondria and Chloroplast genes do follow the chromosomal theory of inheritance
FALSE
Mitochondria and chloroplast genes are passed by one offspring this is called ______ _______
maternal inheritance
Early geneticists realized that could obtain information about the ______ between genes on a chromosome
distance
If crossover occurs, parental alleles are recombined producing ________ ________
recombinant gametes
What was Creighton’s and McClinktock’s experiment’s hypothesis?
Crossing over involves a physical exchange of genetic material between two
Creighton’s and McClintock’s predication was that recombination of visible differences in a chromosome should correlate with genetic recombination of _______
alleles
Creighton and McClintock found that genetically recombinant progeny also have ________ _________ ________
physically recombinant chromosomes
What did Creighton and McClintock conclude about there experiment?
That a physical exchange of genetic material accompanied genetic recombination
___________ is the basis for genetic maps
Recombination
_______ _________ out Morgan’s observation that recombinant progeny reflected relevant location of genes in quantitative terms
Alfred Sturtevant
T or F: The physical distance on a chromosome and the probability of recombination (corssover) occurring between the gene loci are indirectly related
FALSE, as one increases so does the other
The distance between genes is proportional to the ________ of recombination events
frequency
What is the equation for the recombination frequency?
recombinant progeny/ total progeny
What is the unit for one map unit?
1 centimorgan
What is the unit for 1? recombination?
1 map unit (m.u)
If homologues undergo two crossovers between loci, then the parental combination is ______
restored
_____ number of crossover events produce recombinant gametes
odd
No crossover or even numbers of crossovers produce ______ gametes
parental
T or F: Relationship between true distance on a chromosome and the recombination frequency is not linear
TRUE
In the three-point testcross, the _____ gene allows tracking of recombination events on either side
middle
In a three-point cross, the class of offspring with two crossovers is the _______ frequent class (most or least)
least
Three-point testcross, uses _____ loci instead two to construct maps
three
Some human traits are controlled by a single _____
gene
Human traits can exhibit _______/_______ inheritance
dominant/ recessive
_______ analysis is used to track inheritance patterns in families
pedigree
Juvenile glaucoma is an example of ________ inheritance
dominant
albinism is an example of ________ inheritance
recessive
What disease causes degeneration of optic nerve leading to blindness
juvenile glaucoma
If a pedigree shows dominant inheritance than the trait appears in ________ generation
every
What condition causes the pigment melanin to not be produced
albinism
With what type of inheritance are:
-males and females affected equally
-most affected individuals have unaffected parents
autosomal recessive inheritance
What genetic disorders affect males more than females?
sex-linked
_______ is a disease that affects a single protein in a cascade involved in formation of blood clots
Hemophilia
T or F: A single amino acid change in a single protein can result in clinical syndrome
True
What disease is
- the first human disease shown to be the result of a mutation in a protein
- caused by a defect in the oxygen carrier molecule, hemoglobin
- leads to impaired oxygen delivery to tissues
sickle cell anemia
What type of allele is particularly prevalent in people of African descent and confers resistance to blood-borne parasite that causes malaria
sickle cell allele
Cystic Fibrosis, Sickle cell anemia, Tay-Sachs disease, and Phenylketonuria are genetic disorders that are ________ _________
autosomal recessive
Hemophilia and Muscular dystrophy are genetic disorders that are ___-____ _______
X-linked recessive
Huntington disease and Hypercholesterolemia are genetic disorders that are ______ _______
autosomal dominant
_______ is the failure of homologues or sister chromatids to separate properly during meiosis
nondisjunction
_________ is the gain or loss of a chromosome, the result of nondisjunction
aneuploidy
_______ is the loss of a chromosome
monosomy
________ is the gain of a chromosome
trisomy
Human embryos trisomic for _______ of the _______ autosomes can survive birth
five, smallest
Trisomy at which chromosomes can survive? (give numbers)
13, 15, 18, 21, and 22
Which trisomy at these chromosomes will cause severe defects and die within a few months?
13,15, and 18
Trisomy at which two chromosomes can survive to adulthood?
21 and 22
Down syndrome is trisomy at which chromosome?
21
What two things can cause down syndrome?
-full third 21st chromosome
-translocation of a part of chromosome 21
T or F: genetic defects can increase as the mother ages
true
T or F: Nondisjunction of sex chromosomes do not generally experience severe developmental abnormalities
True
What is caused when it is XXX
triple X
What is called when it is XXY
Klinefelter syndrome
What is it called when it is XO
turner syndrome
What is it called when it OY?
nonviable zygote
What is it called when it is XYY?
Jacob syndrome
