Midterm Review Flashcards
A diploid somatic cell from a rat has a total of 42 chromosomes (2n=42). What is the total number of chromosomes present in prophase I of meiosis?
42
Consider the same rat described in question 1. What is the total number of chromosomes present per cell in metaphase II of meiosis?
21
A chromosome with a centromere at the very end is called
Telocentric
Accurate differences between incomplete dominance and simple dominance are showing in all of the following statements, except:
The phenotypic ratio from a cross between two heterozygotes in both simple dominance and incomplete dominance is 1:2:1
Which of the following list shows possible phenotypic ratios that could occur in various types of crosses dealing with a single pair of alleles?
3:1, 1:1, 1:2:1
In humans, alkaptonuria is a metabolic disorder in which affected persons produce black urine. Alkaptonuria results from an allele (a) that is recessive to the allele for normal metabolism (A). Sally has normal metabolism, but her brother has it. Sally’s father is affected and mother is normal. If parent’s have another child, what is probability child will have alkaptonuria?
1/2
In snapdragons, flower floor (red, pink or white) is inherited through incomplete dominance. If plants producing pink flowers are crossed with plants producing white flowers, what is probability that the offspring will produce white flowers?
1/2
Which of the following statements about Barr body formation is false?
The number of Barr bodies is 1 less than the total number of sex chromosomes.
A fruit fly possesses the following chromosome: XXYYY and 2 sets of autosomes. What is the most likely sexual phenotype?
Female
In shorthorn cattle, the heterozygous condition of the alleles for red coat color and white coat color is roan coat color. If two roan cattle are mated, what proportion of progeny will have red coat color?
1/4
Which of the following would serve least well as a model for understanding basic mechanisms of inheritance?
Humans
Which of the following was not one of Mendel’s conclusions based on his monohybrid crosses?
Genes are carried on chromosomes
If a female Drosophila that is heterozygous for a recessive X-linked mutation is crossed to a wild-type male, what proportion of female progeny will have the mutant phenotype?
0%
Achondroplasia is a common cause of dwarfism in humans. All individuals with achondroplasia are thought to be heterozygous at the locus that controls this trait. The offspring of two individuals with achondroplasia occur in a ratio of 2 achondroplasia: 1 normal. What is the most likely explanation for these observations?
?
The movement of genetic material between non-homologous chromosomes
Translocation
