Boring Old Defintions
What are the 4 types of signaling molecules? Which is most important for its role in embryologic development?
Endocrine, paracrine, autocrine, juxtacrine. Paracrine is most important.
A homeotic mutation is one in which:
one body part is substituted for another during development.
Mutation in this signaling molecule expression results in an increased risk of colon cancer.
Wnt
What is the probability of 2 dice rolls resulting in a 6?
1/6 x 1/6 = 1/36
1
In which direction/order are HOX genes expressed?
3' genes are expressed earlier and expressed anteriorly compared to 5' genes
Which of the following is a condition associated with a missense mutation at the HOXD-13 loci?
A. Chronic Bradycardia
B. Synpolydactyly
C. Retinopathy
D. Polyps in the Colon
B. Synpolydactyly
1/36
If a population has the following genotype frequencies, AA = 0.30, Aa= 0.50, and aa= 0.20, what are the allele frequencies?
A = .55
a= .45
What is a teratogen? Which is the number 1 known teratogen in the US?
Teratogen = substance/drug capable of interfering with development of and embryo/fetus that leads to birth defects. #1 in US = alcohol
Which digit results from a high expression of SHH during embryologic development?
Which master control gene is involved in eye development?
PAX6
What is the probability two heterozygous individuals having a male offspring who is homozygous recessive?
1/2 x 1/4 = 1/8
In a population with two alleles, B and b, the allele frequency of b is 0.32. What would be the frequency of the homozygous dominant if the population is in Hardy-Weinberg Equilibrium?
Define "selection coefficient"
measure of relative fitness of a phenotype
Describe how FGFR3 plays a role in bone development.
Binding to FGFR3 = slowing of chondrocyte proliferation. The longer the chondrocytes persist, the longer it takes for osteocytes to take over. If FGFR3 is bound sooner, chondrocytes are slowed sooner, osteocytes take over sooner -> shorter bone length
What condition results from underactivity of FGFR3?
Apert Syndrome
In a bag of 100 skittles, 30 are green, 20 are red, 20 are orange, 20 are yellow, and 10 are purple. What is the probability of drawing a green or yellow skittle?
30/100 + 20/100 = 1/2
What does it mean if probability of something is mutually exclusive? What calculation method would you use?
Two or more events that cannot happen simultaneously. ADDITION
Describe the significance of the helix-turn-helix structural motif within which homeobox encodes a DNA-binding domain. (Hint: Major and minor grooves)
DNA can be bound in major groove or minor groove. Major groove provides access to bases. This allows for binding to the sequence in a specific way. The minor groove gives access to backbone.
What are two conditions that can result from mutations of CDMP1? (Hint: heterozygous and homozygous forms)
Heterozygous = brachydactyly type C
Homozygous recessive = Grebe dysplasia
A couple comes into your clinic for genetic/fertility counseling. The woman is concerned about passing on her autosomal recessive condition of babbling (bb) to her children. Her partner does not have the condition, but does have family history for it, and recently learned that he is a carrier for the allele. What is the probability that their child will not have the babbling condition?
1/2