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Flashcards in The Gene Deck (20):
1

If a segment of DNA is 5'-TAG GAT TAG:-3', the RNA that results from the transcription of this segment will be:

A. 3'-AUC CUA AUC-5' D. 3'-UAC GAU UAG-5'
B. 3'-AAC GAU UAA-5' E. 3'-ATG CTA ATA-5'
C. 3'-TAC GAT TAU-5'

A. 3'-AUC CUA AUC-5'

2

Transfer RNA is a molecule that serves to bring together specific:

A. Amino acids and rRNA molecules
B. Proteins and mRNA codons
C. Amino acids and mRNA codons
D. Proteins and anticodons
E. Anticodons and rRNA molecules

C. Amino acids and mRNA codons

2

Once transcribed, eukaryotic mRNA undergoes substantial alteration that results primarily from:

A. Union with ribosomes
B. Fusion into circular forms known as plasmids
C. Fusion with other newly transcribed mRNA molecules to form larger translatable units
D. Linkage to histone molecules
E. Excision of interons

E. Excision of interons

3

The relative location of four genes on a chromosome can be mapped from the following data on crossover frequencies:

GENES FREQUENCIES OF CROSSOVER
B and D 5%
C and A 15%
A and B 30%
C and B 45%
C and D 50%

Which of the following represents the relative position of these four genes on the chromosome?

A. ADCB B. CABD C. CBAD D. DBCA E. ABCD

B. CABD

4

If 2n=48 for a particular cell, then the chromosome number in each cell after meiosis would be:

A. 6 D. 24
B. 12 E. 48
C. 96

D. 24

5

Which of the following correctly describes the relationship of the dark-coated allele to the albino condition?

A. It is recessive.
B. It is dominant.
C. It is codominant.
D. The alleles are linked.
E. It is a polygenic inheritance pattern.

B. It is dominant.

6

Which of the following statements concerning a gene is correct?

A. A gene can code for a specific protein.
B. A gene undergoes crossing-over during DNA replication.
C. A gene that is very similar in sequence in a human and in a bacterium is probably a recent mutation.
D. A gene that is expressed in every offspring of every generation is recessive.
E. A gene can exist in alternate forms called introns.

A. A gene can code for a specific protein.

7

All of the following are true statements about meiosis in mammals EXCEPT:

A. It follows DNA replication.
B. It serves as a factor in bringing about variation among offspring.
C. It produces four genetically identical gametes.
D. It occurs only in reproductive structures.
E. It produces cells with the haploid number of chromosomes.

C. It produces four genetically identical gametes.

8

In garden peas, a single gene controls stem length. The recessive allele (t) produces short stems when homozygous. The dominant allele (T) produces long stems. A short-stemmed plant is crossed with a heterozygous long-stemmed plant. Which of the following represents the expected phenotype a of the offspring and the ratio in which they occur?

A. Long-stemmed plants only
B. Short-stemmed plants only
C. 3 long-stemmed plants: 1 short-stemmed plant
D. 1 long-stemmed plant: 3 short-stemmed plants
E. 1 long-stemmed plant: 1 short-stemmed plant

E. 1 long-stemmed plant: 1 short-stemmed plant

9

A human cell in prophase of mitosis can be distinguished from a human cell in prophase I of meiosis by the presence of:

A. A spindle in the mitotic cell
B. Half as many chromosomes in the meiotic cell
C. Twice as many chromosomes in the meiotic cell
D. Paired homologous chromosomes in the meiotic cell
E. Kinetichores in the mitotic cell

D. Paired homologous chromosomes in the meiotic cell

10

A geneticist observed 22 pairs of autosomes and one X chromosome in a photomicrograph of the chromosomes of a certain female. The geneticist diagnosed this condition as:

A. Klinefelter's syndrome D. Trisomy-x syndrome
B. Down's syndrome E. XYY syndrome
C. Turner's syndrome

C. Turner's syndrome

11

Chargaf's ratios, A/T = 1 and C/G = 1 ultimately led to the concept of:

A. "Unzipping" of DNA
B. The complementarity of base pairs in DNA
C. The helical structure of DNA
D. Antiparallel strands in DNA
E. The stacking of nucleotides in DNA

B. The complementarity of base pairs in DNA

12

Which is not caused by a virus?

A. Flu D. Polio
B. AIDS E. Antiparallel strands in DNA
C. Herpes

E. Antiparallel strands in DNA

13

A primary sex cell undergoing meiosis has 46 chromosomes. The number of centromeres observed during Prophase I is :

A. 46 D. 12
B. 92 E. 8
C. 23

A. 46

14

When two hybrids are crossed, the recessive trait which was hidden in the F1 generation may appear in the F2 generation. This statement illustrates the:

A. Law of Dominance D. Law of Segregation
B. Law of Independent Assortment E. Law of Unit Characters
C. Law of Partial Dominance

D. Law of Segregation

15

If red hair, blue eyes, and freckles were consistently inherited together, the best explanation would be that:

A. Gene duplications have occurred.
B. The genes for these traits are linked on the same chromosome.
C. Both parents have red hair, blue eyes and freckles.
D. These traits are dominant to others.
E. These traits are recessive characteristics.

B. The genes for these traits are linked on the same chromosome.

16

The Himalayan rabbit is white with black extremities. If fur is shaved from a white part of its body and an ice pack is applied, the new fur is black. The result provides evidence that:

A. Coat color is due to partial dominance.
B. Diet affects coat color.
C. Light is responsible for the black pigment.
D. Atmospheric pressure determines hair color.
E. Environment affects the expression of some genes.

E. Environment affects the expression of some genes.

17

The representation of the fetus' chromosomes as shown above is called a:

A. Karyotype D. DNA fingerprint
B. Testcross E. Gene map
C. Pedigree

A. Karyotype

18

The phage tail fibers contain the enzyme lysosome which is necessary for stage:

A. 4 D. 8
B. 6 E. 3
C. 1

E. 3

19

Which is not involved in the splicing of RNA?

A. Exons D. Introns
B. Spliceosome E. RNA polymerase
C. SnRNA

E. RNA polymerase