Biology: Quiz 4: Human Genetics
What would be a female bleeder's genotype? (Let X B stand for the normal condition for clotting and X b stand for the recessive hemophilia allele.)
Xb Xb
The extra chromosome which produces Down's syndrome is:
an autosome
What genotype produces voices?
bass and soprano is SS, of baritone and mezzo-soprano SA, and of tenor and alto AA.
Why would it be wise for a woman carrying the hemophilia gene to keep her son from being circumcised?
because the probability of hemophilia would be 1:2
The factors that are responsible for the ABO blood type, or the Rh, are located on the surface of the
erythrocyte
Some scientists believe that sickle-cell anemia is a beneficial mutation because it:
increases resistence to malaria
Nutrition affects development of the physical brain therefore:
nutrition is related to intelligence
The Rh ______ condition occurs in most of the world population.
positive
The traits for blood type and Rh are the result of the presence or absence of particular ______ on the erythrocytes.
proteins
Sex-linked inheritance refers to
recessive hereditary alleles usually being passed on the X chromosome.
In the ABO series, the gene for blood type O is______, while A and B are______genes, and AB is ______.
recessive, dominant, codominany
When using data from population genetics research:
the sample must have a high probability of representing the population
Why do identical twins have the same set of genes?
they were born of one fertilized ovum
A female can be susceptible to expressing hemophilia.
true
In general, the "Y" sex chromosome does not appear to exert as much genetic influence as the "X" chromosome.
true
The blood type trait is controlled by more than two alleles for a given gene and therefore is called multiple alleles.
true
The presence of tight ligaments in the thumb is a recessive trait.
true
A pedigree is very helpful to a counselor when
when they are predicting the probability of a recessive gene being present and the chances for an offspring to receive the gene and express the trait.
The Talmud permitted a father with hemophilia to have his son circumcised. Would this preclude all possible problems?
yes-if the mother is not a possible carrier
The genotype of persons with the sickle-cell trait, but often not exhibiting sickle-cell, is
HbS HbS
Turner's syndrome
(XO) An abnormality where one of the sex chromosomes is missing leaving a total of 45
When does nondisjunction occur which affects inheritance?
meiosis
In a large population, approximately 65 percent are tasters and 35 percent are nontasters. Does the class compare favorably to the general population?
yes
Klinefelter syndrome
(XXY) An abnormality affecting males where there is an extra X chromosome
Each member of a class sampled a piece of PTC testing paper. Thirty people sampled the chemical. Twenty persons were tasters. How many had heterozygous genes?
0-20
Each member of a class sampled a piece of PTC testing paper. Thirty people sampled the chemical. Twenty persons were tasters. How many had homozygous recessive genes?
10
Each member of a class sampled a piece of PTC testing paper. Thirty people sampled the chemical. Twenty persons were tasters. How many had homozygous genes?
10-30
Down's syndrome is a condition where an extra chromosome is produced on the _____ chromosome.
21st
A normal human body contains:
23 pairs of chromosomes, 46 total chromosomes
holandric genes
A gene located on the Y chromosome in XY species
Hemophilia
A hereditary condition for bleeding due to the inability to clot properly
Rh factor
An inherited protein found on the surface of the red blood cell membrane
The genotype of the person with normal red blood cells in all environmental conditions is
HbA HbA
pedigree
The ancestral history of an individual; a chart showing the history of a trait in the family
population genetics
The study of a hereditary trait in a large population
Two of the risk factors for Down's syndrome include which of the following?
-increased age of female -infectious hepatitis
Choose from the following list of diseases those that are sex-linked.
-night blindness -rolling eyeballs -nonfunctional sweat glands -white forelock -muscular dystrophy -certain deafness -color blindness -diabetes
Down Syndrome
A condition caused by the presence of an extra chromosome 21
gene pool
All of the genes present in a specific population
Codominance
Both members of an allelic pair contribute equally to the phenotype
gene frequency
How common the gene is in the population
sickle cell trait
In conditions of low oxygen some cells sickle
The large number of potential gene ______ make it unlikely that any two people will be identical.
combinations
The hemoglobin of sickle cell anemia:
differs from the normal protein by one amino acid
A family pedigree is a chart of various patterns that shows a general trend.
false
Hemophilia is a condition where the blood clotting action is dangerously high.
false
A person with Klinefelter's syndrome possesses:
has a extra X chromosome
What is true about the heterozygous sickle-cell (HbA HbS) condition?
sickle-cell anemia is expressed under conditions of oxygen deficiency
sickle cell anemia
A hereditary form of anemia