Genetics Midterm Review Sheet (Sarah) Flashcards
Huntington disease is the result of a HAPLO-insufficient mutation.
False
Klinefelter syndrome (when an individual has GENOTYPE XXY) can be the result of non-disjunction in Meiosis 2 of the father. (Aka: father can only get XYY)
False
What is the difference between trisomy and triploidy? Give a short definition of each and indicate what each means in terms of “n”. (Remember “n” refers to the number of chromosomes)
Trisomy: Has one extra copy of chromosome, causing developmental abnormalities.
2n+1
Triploidy: Has an extra third copy of all chromosomes, and is often always fatal.
3n
Answer the following questions about a cell that is 2n=4 in mitosis.
How many chromatids are present in the metaphase plate?
8
Answer the following questions about a cell that is 2n=4 in mitosis.
How many bivalents (CHROMOSOMES) are present?
0 because there are no homologous in mitosis/tetrads
Answer the following questions about a cell that is 2n=4 in mitosis.
What are being separated at anaphase?
Sister chromatids
Answer the following questions about a cell that is 2n=4 in Meiosis:
How many chromatids are present on the metaphase plate?
Meiosis 1:
Meiosis 2:
M1: 8
M2: 4
Answer the following questions about a cell that is 2n=4 in Meiosis:
How many tetrads are present?
Meiosis 1:
Meiosis 2:
M1: 2
M2: 0
Answer the following questions about a cell that is 2n=4 in Meiosis:
What are being separated at anaphase?
Meiosis 1:
Meiosis 2:
M1: homologous
M2: sister chromatids
Galactosemia is a RECESSIVE human disease that is treatable by restricting lactose and glucose in the diet. Sally Smithers and her husband are both HETEROZYGOUS (a/A or B/b) for the galactosemia gene.
Sally is pregnant with twins. If she has fraternal twins (2 events)/(non-identical) twins, what is the probability that both girls will have galactosemia?
1/21/21/4**1/4= 1/64
Galactosemia is a RECESSIVE human disease that is treatable by restricting lactose and glucose in the diet. Sally Smithers and her husband are both HETEROZYGOUS (a/A or B/b) for the galactosemia gene.
If she has identical twins (1 event) what is the probability that both girls will have galactosemia?
1/2*1/4=1/8
Galactosemia is a RECESSIVE human disease that is treatable by restricting lactose and glucose in the diet. Sally Smithers and her husband are both HETEROZYGOUS (a/A or B/b) for the galactosemia gene.
If Sally and her husband have four children, what is the probability that none of the four will have galactosemia? Assume that there are NO twins.
3/43/43/4*3/4=81/256