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Bio 3 Test

Terms

undefined, object
copy deck
each gene makes a...
protein
a gene is a region of the DNA on a...
chromosome
Humans have about how many genes
30,000
Where a gene is located does not determine its...
function
Every gene's location on a chromosome is...
fixed
How many chromosomes do humans have?
46
Of the 46 chromosomes, 44 are in (22 pairs) of called...
autosomes
Autosomes do not determine...
SEX
humans have how many sex chromosomes?
Two
females have what kind of sex chromosomes?
Two Xs
A males sex chromosomes are...
One X and One Y
The Y chromosome has very few genes on it, but it has a critical gene on it called....
SRY
The SRY gene causes what to form on the embryo?
testes
What hormone do the testes secrete?
testosterone
What does testosterone cause the embryo to do?
develop a male
If there is no SRY gene or it is inactive, what forms in the embryo?
ovaries
Occasionally a female will have XY chromosomes because the SRY gene is what?
inactive
Sometimes a male will have two XX chromosomes because one X chromosome gained a...
SRY gene
Abnormally having whole extra sets of chromosomes is called
polyploidy
To have three extra sets of chromosomes instead of two
triploid
A human with three extra sets of chromosomes (triploid) will...
die (it's lethal for humans)
Species other than humans with three extra sets of chromosomes (triploid) cannot what?
reproduce (they are sterile or a source of seedless fruit)
if something is missing a single chromosome it is called
aneuploid
aneuploid (a missing single chromosome) is caused by...
meiosis problems
When two chromosomes go to the same pole instead of opposite poles during meiosis what is caused
aneuploidy
aneuploidy is bad because gene numbers are out of...
balance
The red and green color receptor genes are located on which chromosome?
X
When the red and green color receptor genes are inactivated what happens?
various forms of color blindness
The blue receptor is located on an ...
autosome chromosome
The blue receptor is rarely
affected
Hemophilia describes a problem when blood
does not clot
Normally blood clots when exposed to air due to...
clotting proteins
Genes for clotting proteins are located on which chromosome?
X
When genes for clotting proteins are inactivated, what happens?
blood doesn't clot and person can bleed to death.
list four examples of sex chromosome aneuploidies
1. XXY 2. XO 3. XYY 4. XXX
The XXY sex chromosome aneuploid is called...
Klinefelter's syndrome
Someone with Klinefelter's syndrome is...
male with feminized features
The XO sex chromosome aneuploid is called...
Turner's syndrome
Someone with Turner's syndrome is...
a female with no ovaries and is sterile
characteristics of an XYY sex chromosome aneuploidy include:
male, with slight problems: acne, reduced intelligence, tall
characteristics of an XXX sex chromosome aneuploidy include:
female, normal (but XXXX, etc is retarded)
autosomal (non-sex chromosomes)aneuploidies occur, but Most (those where one chromosome is missing) die when?
before birth
Down's Syndrome is a result of and
autosomal aneuploidy
an autosomal aneuploid that demonstrates 3 copies of chromosome 21 is...
Down syndrome
4 characteristics of a Down Syndrome individual
1 survives to adulthood 2. mentally retarded 3. heart defects 4. characteristic appearances
The most common form of mental retardation is ...
down syndrome
older mothers or fathers produce more aneuploid babies than their younger counterparts?
mothers
older males or females have no effect on reproducing aneuploid babies.
males
name two structural changes in chromosomes
inversions and translocations.
creating a structural change means breaking a chromosome, which often means destroying a gene necessary for...
life
chromosomes with structural changes often have trouble completing
meiosis
trouble with meiosis results in
aneuploid gametes
what kind of Down's Syndrome is inherited?
translocational Down's
what causes translocational Down Syndrome?
translocation involving chromosome 21
Genes on the X chromosome are sex-
linked
Genes on any chromosome other than the Xs are called...
autosomal
The X chromosomes have many genes like other chromosomes. The Y however, has...
few genes
Males with only one X chromosome express every allele on their
X chromosome, whether dominant or recessive
The Y chromosome has very few...
genes
Because females have two X chromosomes, recessive mutant alleles are usually covered up by
dominant normal alleles
Sex-linked traits are more common in males or females?
males
Name the 3 color receptors in our eyes
red, green, blue
If blood doesn't clot someone could...
bleed to death
Sons get their Y chromosome from their father and their X chromosome from their
mother
daughters get X chromosomes from which parent(s)?
both mother and father
sons do not get X chromosomes from which parent?
father
the offspring of a cross depend on the sexes of the mutant and normal...
parents
If a color blind male and normal female cross will offspring be colorblind?
no, they will all be normal but females will carry the trait
If females carry the colorblind trait they are called
heterozygotes
heterozygotes are carriers of
a recessive gene
if a normal male crosses with a colorblind female will the male offspring be colorblind?
yes
if a normal male and a colorblind female cross, will the female offspring be colorblind?
no, but they will be carriers (heterozygotes)
some traits are not sex-linked but rather sex-
influenced
sex- influenced traits are not located on this chromosome...
X
Male patern baldness is a sex-linked or sex influenced trait?
sex-influenced
If an offspring receives a bald allele from both the father and the mother, will it be bald?
Yes, no matter what sex. The offspring is homozygous
If an offspring is heterozygous for male pattern baldness will they be bald?
Only if the offspring is male. Females will have normal hair.

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