Chapter 11/12 Genetics Flashcards
Mendel’s theory of independent assortment states that…
Each hereditary unit is inherited separately from other hereditary units.
A. ⬜️——–⚫️
ww. | Ww
|
—————————-
|. |. |. |. |. |
B. ⚪️—◾️ ⚫️ ◾️—⚪️ ⬜️ ⬜️ ⬜️
|. |
C. ◾️. |
———–
D. ⚪️. ◽️. ◾️—–⚪️
ww= wooly hair. Ww=non wooly
2.) what’s the likelihood that the progeny of D-3 and D-4 will have wooly hair ?
3.) what is the genotype of Individual B-5
4.) what is the probability that individual C-1 is Ww?
- ) 50%
- ) ww
- ) 100%
Black fur in mice (B) is dominant to brown fur (b) Short Tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt x BBtt with have black fur and long tails?
1/2
If a study of several pedigrees demonstrates that two parents express a characteristic and none of their children express it, then the trait is controlled by…
Dominant gene
If nondisjunction occurs during meiosis …
One half of the resulting cells are n+1 and the other half are n-1
Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. They rarely love past their 20’s. How likely is it for a woman to have this condition?
A woman would rarely have this condition; it is rare that an affected male would mate with a carrier female
Which boxed area on the generalized karyotype illustration below represents a pair of autosomes?
|| ||
| | | |
(1).
|| ||
| | | |
(12)
|| ||
| | | |
(XX)
Both 1 and 12
I’m cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous offspring of red and white homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red: 2 roan: 1 white?
Roan x Roan
Which of the following is a test cross? (Y means the allele’s identity is unknown)
RyMy x rrmm
A small region of a protein from three species is sequenced and found to be as follows:
• species X is alanine, glycine, glycine, threonine, alanine
• species Y is alanine, glycine, threonine, alanine
• species Z is alanine, valine, glycine, threonine, alanine
The difference in the amino acid sequence of species Y is most likely due to…
A deletion
Homologous sets of genes ABCDEF and aBCdEF are located on nonhomologous chromosomes. Crossing between them is suppressed because their locations are the result of….
A translocation
Homologous sets of genes ABCDEF and AEDCBF are located on homologous chromosomes. Crossing is suppressed because of….
An inversion
The nucleotide sequences of homologous regions of DNA of two species are AATGCCCCGTTA and AATGCCCCGCTTA. If this isn’t the result of a nucleotide base-pair addition, then is it due to…
A gene duplication
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you except from the cross of a black female and an orange male?
Tortoiseshell female; black male
What is the mechanism for the production of genetic recombinants?
Crossing over and independent assortment.
You are a genetic counselor, and a couple comes to you with condemns that if they have a child together it could have hemophilia. Neither one of them had hemophilia, but the woman’s biological father did have an X-linked recessive form of hemophilia. What’s correct to tell them?
Each of their male offspring will have a 50% chance to have hemophilia, and while the females shouldn’t have it, they will each have a 50% chance to be carriers
D= dark leaves (dominant) d= light leaves (recessive)
D. d.
D--------
|1. 2. |
| |
d 3. 4.|
---------
Which plant(s) are true bred?
Which boxes correspond to plants with dark leaves?
- ) 1 and 4
2. ) 1,2,3
Some dogs have erect ears; others have dropping ears. Some dogs bark when following a scent; others are silent. Erect ears and marking are due to dominate alleles located on different chromosomes. If two don’t rids are crossed…
All droopy-eared, silent offspring are pure-bred
An obstetrician knows that one of her patients is a pregnant woman whose fetus is at risk for a serious disorder that is detectable biochemically in fetus cells. The obstetrician would most reasonably offer what procedure to her patient?
Amniocentesis or CVS
A sexually reproducing animal had two unlinked genes, one for head shape, (H) and one for tail length, (T). It’s Genotype is HhTt. Which of the following genotype a is possible in a gamete from this organism?
HT
What is the genetic cross between an individual showing a dominant phenotype (but unknown genotype) and a homozygous recessive individual called?
A testcross
A woman who has blood type A, has a daughter who is blood type O positive and a son who is B negative. Rh positive is a dominate trait over Rh negative.
What is a phenotype for the father?
What is a probable genotype for the mother?
What is a possible genotype for the mother?
- ) B
- ) I(A)irr
- ) I(A)i
Mendel’s second law of independent assortment has its basis in what events of meiosis 1?
Alignment of tetrads as the equator
Suppose that a hemophilic male (X-linked recessive allele) and a female carrier have a no hemophilic daughter with Turner syndrome. Nondisjunction could have occurred in…
The father only
Genes are…
- Located on chromosomes
- Inherited in the same way as chromosomes
- Arranged in a linear sequence on chromosomes.
Males tend to be affected in greater numbers by X-linked recessive genetic disorders than are females because…
Males only have one X chromosome
Feather color in budgies is determined by two different genes Y and B. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white.
- ) two blue budgies were crossed and made 22 offspring, 5 were white. What’s the genotype a for the parents?
- ) what type of allele interaction is being shown here?
- ) yyBb and yyBb
2. ) epistasis
◾️---⚪️
|
------------
◽️. ⚫️. ⚫️---◽️
|. ^
--------------------------
⚫️. ◾️---⚪️. ◽️---⚪️
|. |
--------- ◽
◽️. ⚫️️
What’s the correct inheritance pattern for this condition?
X-Linked dominant
Mendel’s observation of the segregation of alleles in gamete formation has its basis in what phases of cell division?
Anaphase 1 of meiosis
Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that…
Traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in F1
An individual who is a carrier of a genetically inherited disease…
Doesn’t have the disease, but may have offspring with the disease
What are punnett squares Used for?
Predicting the results of genetic crosses between organisms of known genotypes
The role of environmental factors on gene expression is illustrated by the…
- Varying plant height of genetically identical yarrow plants when grows at different elevations
- Flower color of hydrangeas grown in soils of differing pH
- Depression response that some persons make to very stressful situations
- Fur pattern of Himalayan rabbits
In humans, clear gender differentiation occurs, not at fertilization, but after the second month of development. What’s the first event of this differentiation?
Activation of SRY in male embryos and masculinization of the gonads (testes)
An achondroplastic male dwarf with normal vision marries a color-blind woman of normal height. The man’s father was six-feet tall and both the woman’s parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive.
- ) how many daughters might be expected to be color-blind dwarfs?
- ) they have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?
- ) none
2. ) 100%
Epistasis vs Pleiotropy
- E: two or more genes affect one phenotype. Ex: color color of labs. One gene for pigment, one for depositing the pigment.
- P: one gene affects more than one phenotype. Ex: Marfan syndrome, one gene that affects connective tissue can have multiple effects on the body such as a weaker heart, taller stature, nearsightedness.
Complete dominance
- Occurs when phenotype a of the heterozygote and dominant homozygote are identical. Ex: Eye color
- Only one allele in the genotype is seen in the phenotype!
Incomplete dominance
- Blended traits. Two birds, one blue, one yellow, make green color.
- The phenotype of F1 hybrids is somewhere between the phenotype of the two parents
- a mixture of the alleles in the genotype is seen in the phenotype
Co-dominance
- Two dominant alleles affect the phenotype in separate, distinguishable ways. Ex: blood types,
- Both alleles in the genotype are seen in the phenotype
Autosomal recessive
- Skips generations.
- Effects males and females equally
- Ex: Cystic fibrosis, sickle cell anemia
Autosomal dominant
- common
- every generation
- affected peeps transmit it to half of children
X-linked recessive
- rare
- skips gens
- affected fathers DONT pass to sons
X-linked Dominant
- common
- affected fathers pass on to all daughters
- equally likely to get it, though is lethal to males, and most die before birth
