19. E) One-half of the offspring would be expected to have Down syndrome.
Explanation: Recombination during meiotic crossing over of a trisomic female with a normal male results in an offspring with two normal carrier females and two males with down syndrome. This happens only if the female parent contains the dominant allele on both X chromosomes.
20. D) A translocation between chromosome 21 and a member of D chromosome group.
Explanation: D group chromosomes are medium acrocentric (13-15). Individuals with familial Down syndrome have an extra part of chromosome 21 as the result of a translocation. If the normal chromosome 21 segregates with translocated chromosome, the gamete produced will have two copies of chromosome 21 and the offspring suffers from familial Down syndrome.
21. B) Various lengths of trinucleotide repeats.
Explanation: Fragile X-syndrome is caused due to variable expansions of CGG trinucleotide repeats in FMR1 gene whereas the variable expansions of CAG trinucleotide repeats in HTT gene results in Huntington's disease.
19) Trisomy 21, or Down syndrome, occurs when there is a nom complement but one (extra)...
Down syndrome, or trisomy 21, in humans is caused by an extra copy of the relatively small, acrocentric 21. Including only chromosome 21, the X chromosome (medium in size and somewhat metacentric) and the Y chromosome (small and acrocentric), draw one possible array of chromosomes in the four sperm cells produced by the complete meiosis of one primary spermatocyte in a male individual with Down syndrome. For the purposes of this question, assume that males with Down syndrome produce normal...
You are presented with a patient, named Gerry, who has Down syndrome (trisomy 21). You determine the nondisjunction event occurred in his mother, named Mary, during meiosis I. The TPTE gene is on chromosome 21. Mary has two different alleles of the TPTE gene (ex. T and t). Do Gerry's maternally-inherited chromosome 21s have the same or different alleles of the TPTE gene? Do not worry about recombination in this question. Same alleles Different alleles Not enough information to determine...
2. (5 PTS) You are presented with a patient, named Gerry, who has Down syndrome (trisomy 21). You determine that the nondisjunction event occurred in his mother, named Mary, during meiosis I. a. You are interested in the TPTE gene, which is near the centromere of chromosome 21. Virtually no recombination occurs between the centromere and the TPTE gene. Mary has two different alleles of the TPTE gene. Would Gerry's two chromosome 21s from his mother have the same or...
that individuals with Down Syndrome (caused by a triplet of genes at chromosome 21, Trisomy 4. It is seen 21) have a shortened life span. Some of this may be due to cardiovascular defects present in about 80% of individuals. A more modern theory is that the cell cycle of individuals with this condition is cycling faster than individuals without the condition. As such, Down Syndrome patients may have an accelerated epigenetic clock. Describe at least three biochemical/genetic/epigenetic factors that...
2 BIO 302 MIDTERM (CH 7-8) 1 Cause of familial Down syndrome is 2. Gain of single chromosome leads to 7 Cotton plant is an example of Triploidy B. Trisomy C.Translocation A Trisomy B. Allopolyploidy C. Amphidiploidy D. Pentaploidy A. Diploidy B.Triploidy C. Tetraploidy D. Trisomy E Monosomy What is "normal chromosome number? 18. What doesn't happen in endopolyploidy'or 3. Diploidy B. Triploidy C. Tetraploidy D. Trisomy EMonosomy 4. Multiple of same genome could be termed as A. Division of...
need help with correct answers. A 21-year-old soldier disappeared in Vietnam. Forty years later, bones are discovered that may include his remains. Which available living relative's mitochondrial DNA would be the most accurate sample to obtain for comparison to determine whether the bones belong to the soldier? Sister's son O Brother's son O Daughter O Father Question 55 1 pts Which of the following is a hereditary disease characterized by excessive intestinal absorption of a dietary iron resulting in a...
Which of the following is TRUE of incomplete penetrance? Select one: a. Epistatic interactions can result in incomplete penetrance in some cases. b. Environmental factors do not influence penetrance. c. Incomplete penetrance implies that some individuals will experience less severe forms of disease, such as cancer or Alzheimer's. d. Incomplete penetrance is never observed with Huntington's disease e. Incomplete penetrance refers to cases in which individuals developing a particular disease (e.g., cancer or Alzheimer's) lack the typical genotype for this...