GENETICS Flashcards
What is a similarity between DNA and RNA?
a. Both are polymers of nucleotides
b. Both are composed of antiparallel strands
c. Both contain adenine, cytosine and thymine
d. Both contain ribose sugar
A. Both are polymers of nucleotides
What does a nucleosome consist of?
a. DNA and histones
b. DNA and chromatin
c. Chromatin and nucleotides
d. Mature RNA and histones
A. DNA and histones
What is a characteristic of the human Y chromosome?
a. It is made of DNA and histones covered by phospholipids
b. It contains some genes that are not present on the X chromosome.
c. It is the largest chromosome in the human karyotype
d. It has a condensed length of approximately 100 um
*u is “mu”
B. It contains some genes that are not present on the X chromosome.
// The human Y chromosome carries genes crucial for male sex determination and spermatogenesis, such as the SRY (Sex-determining Region Y) gene, which is responsible for initiating male sex determination.
Which is a valid comparison between prokaryotic and eukaryotic DNA?
Prokaryotic | Eukaryotic
a. one circular chromosome | one linear chromosome
b. plasmids present | plasmids absent
c. contains uracil | contains thymine
d. associated with histone | associated with proteins
B. plasmids present | plasmids absent
// A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell’s chromosomal DNA.
Which of the following sequences represents chromosome number during human fertilization?
a. 2n -> n + n
b. n + n -> 2n
c. 2n -> 2n
d. n -> n
B. n + n -> 2n
The F_1 offspring of Mendel’s classic pea cross always looked like one of the two parental varieties because
a. different genes interacted to produce the parental phenotype
b. no genes interacted to produce the parental phenotype
c. one allele was completely dominant over another
d. the traits blended together during fertilization
C. one allele was completely dominant over another
In peas, a dominant allele (R) produces a round pea shape, while a recessive allele (r) produces a wrinkled shape. At a second locus on a different chromosome, a dominant allele (Y) produces yellow-colored seeds, while a recessive allele (y) produces green-colored seeds. If a cross involving two pea plants produces 1/4 wrinkled seeds and 1/2 yellow seeds, which of the following represents the parental genotypes?
a. RRYY x rryy
b. RrYy x rryy
c. RrYy x Rryy
d. RrYy x RrYy
C. RrYy x Rryy
A couple has three children, all of whom have brown eyes and blond hair. Both parents are homozygous for brown eyes (BB) but one is a blond (rr) and the other is a redhead (Rr). What is the probability that their next child will be a brown-eyed redhead?
a. 1/16
b. 1/8
c. 1/4
d. 1/2
D. 1/2
Given the parents AABBCc x AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?
a. 1/4
b. 1/8
c. 3/4
d. 3/8
C. 3/4
In cats, black fur color is caused by an X-linked recessive allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What offspring would you expect from the cross of a black female and an orange male?
a. black female; orange male
b. orange female; orange male
c. tortoiseshell female; black male
d. orange female; black male
C. tortoiseshell female; black male
What is an exception to the central dogma of molecular biology?
a. Viruses can translate without RNA
b. Viruses sometimes transfer information from RNA to DNA
c. Viruses sometimes transfer information from DNA to RNA
d. Viruses sometimes transfer information from proteins to DNA
b. Viruses sometimes transfer information from RNA to DNA
// The central dogma of molecular biology states that DNA contains instructions for making a protein, which are copied by RNA
DNA controls protein synthesis, the process by which proteins are made from amino acids. If the template strand of DNA has a CATAGAT arrangement, what would be the sequence of the complementary strand after transcription?
a. GTATCTA
b. TGCGAGC
c. ATCTATG
d. GUAUCUA
D. GUAUCUA
//
1. Find complementary strand
G <-> C
A <-> T
so it becomes GTATCTA
2. Transcribe
T -> U
so it becomes GUAUCUA
Which genetic condition can be diagnosed by karyotyping?
a. Trisomy 21
b. Hemophilia
c. Color blindness
d. Sickle-cell anemia
A. Trisomy 21
// Karyotyping detects changes in chromosome number / structure
Characteristics of conditions:
Trisomy 21 - Extra copy of chromosome 21
Hemophilia - Mutation
Color blindness - Mutation
Sickle-cell anemia - Mutation
Mutation - change in cell SEQUENCE (not structure)
Which process can be used to amplify small fragments of DNA?
a. Gel electrophoresis
b. Polymerase chain reaction
c. DNA profiling
d. Electron microscopy
B. Polymerase chain reaction
// Polymerase chain reaction (PCR) is a widely used technique to amplify (make many copies of) small fragments of DNA
Gel electrophoresis - separates DNA fragments
DNA profiling - creates unique pattern of DNA fragments for identifying individuals
Electron microscopy - Visualizes structure of samples using electron beams
