14.1 Human Chromosomes Flashcards
Genome
the full set of genetic information that an organism/species carries in it DNA
Kartyotype
a micrograph that shows the complete diploid set of chromosomes, grouped together in homologous chromosomes, arranged in order of decreasing size
Sex chromosomes
2 of the 46 chromosomes in the human genome that determine the sex of the organism – 2 types
The study of any genome starts with
Chromosomes
How many chromosomes (arranged in pairs) are in a typical human karyotype
46
What are the 2 types of sex chromosomes
X and Y
What are the sex chromosomes of females?
X and X
What are the sex chromosomes of males?
X and Y
The chance of having a male/female offspring is 50:50 because
The sperm cells have a 50:50 chance of carrying the X or Y chromosome
All human egg cells carry __ ____ chromosome
1 X
___ of sperm cells carry a _ chromosome and the other __ chromosome
half, X, Y
There are more than _____ genes found on the X chromosome
1200
What is smaller the X or Y chromosome
Y
The Y chromosome contains about ____ genes
140
What are most of the genes of the Y chromosome for
male sex determination and sperm development
Autosomal Chromosomes are also know as
autosomes
autosomal chromosomes
remaining chromosomes (not sex )
how many autosomal chromosomes are there
44
Mendelian patterns of Inheritance show
how human genes are inherited
How many ways are human traits transferred
3
What are the three methods of transmission of human traits
simple dominance
codominance
sex-linked
Simple dominance
follow recessive and dominant allele rules
What are some examples of traits that follow simple dominance
Hair/skin color, Rh blood group, Cleft chin, widow’s peak
Rh blood group is aka
Rhesus factor
How many forms does Rh have
2
What are the two forms of Rh
Rh+ and Rh-
Which form of Rh is dominant and which is recessive?
Rh+ is dominant and Rh- is recessive
What are some examples of traits that follow codominant inheritance
ABO blood group
ABO blood group is determined by
a gene with three alleles (IA, IB, and i)
What alleles in the ABO blood group gene are codominant
IA and IB
Because IA and IB are codominant what do they produce
Blood type AB, in which both A and B antigens are produced on the surface of red blood cells
Antigens
proteins that are antibody generators that tell white blood cells what to do and create antibodies
The i allele is
recessive
What antigens does Type A blood produce?
A
What antigens does Type B blood produce?
B
What antigens does Type O blood produce?
None
What antigens does Type AB blood produce?
A and b
What antibodies are present for Type A blood
Anti B
What antibodies are present for Type B blood
Anti A
What antibodies are present for Type AB blood
None
What antibodies are present for Type O blood
Anti A and Anti B
What blood type is the universal acceptor?
AB+
What blood type is the Universal Donor
O-
Can positive blood receive negative blood?
yes
Can negative blood receive positive blood?
no
What are some examples of traits that follow sex linkage
Red-GreenColor Blindness and Hemophilia
Sex linked gene
gene located on a sex chromosome (X or Y)
Red-Green Color Blindness and Hemophilia are more common in
males
Why is red-green color blindness more common in males
bc the color vision genes are located on the X chromosome
Barr Body
(methylated X chromosome) A dense region in the nucleus that is formed when one of the X chromosomes of a female is randomly turned off during X-Chromosome inactivation
Why are Barr Bodies created?
bc females have an extra X chromosome
X-Chromosome Inactivation
the process of randomly switching off one of the X chromosomes of females because they have an extra
How does X Chromosome Inactivation happen?
Covering the nucleotides of the sex chromosome with molecules, so RNA polymerase cannot get to it
X Chromosome inactivation only occurs in
females
What is an example of how X Chromosome Inactivation is shown phenotypically?
Female Calico cats generally have more colorful coats
Why do female calico cats generally have more colorful coats?
the gene that controls the color of coat spots is located on the X chromosome. If a female cat is already heterozygous for coat spot color it will have two different coat spot colors. Then, during X Chromosome Inactivation the other chromosome is turned on and off which may or may not give the cat a third coat spot color
Pedigree
a chart that shows whether a trait is caused by a dominant or recessive allele. Shows the presence or absence of a trait according to the relationship between parents, siblings, and offspring
What organisms can use pedigrees
all
In pedigrees, circles represent
females
In pedigrees, squares represent
males
In pedigrees, a vertical line and a bracket connects
parents to children/siblings
In pedigrees, non shaded shapes represent
no expression of trait
In pedigrees, shaded shapes represent
expression of trait
In pedigrees, horizontal lines between males and females represent
mating
In pedigrees, half shaded, half not shaded shapes represent
Heterozygous for trait or could be one of two genotypes - no way of knowing for sure
In pedigrees people are determined with
Roman numerals
How do Roman numerals determine people in a pedigree
Upper case Roman numeral of row - lower case roman numeral of person in row
Pedigrees allow us to infer _____ of family members
genotypes
B lymphocyte
(B-cell) cells that recognize an antigen and clump the blood up if it is not compatible to the blood type
Who discovered sex linked genes
Thomas Morgan
What did Thomas Morgan study
fruit flies
How did Thomas Morgan discover sex linked gene
He realized that there are no F2 females with white-eye color
