Genetics
Genes
DNA & Protein synthesis
Viruses
Stuff
100
Consider an organism with a genotype of HhTt. Which of the following is possible in a gamete from this organism? A. HT B. Hh C. HhTt D. Tt E. tt
A. HT
100
The frequency of crossing over between any two linked genes is ___________. A. higher if they are recessive B. difficult to predict C. determined by their relative dominance D. the same as if they were not linked E. proportional to the distance between them
E. proportional to the distance between them
100
Suppose one was provided with an actively dividing culture of E. coli bacteria to which radioactive thymine (T) had been added. What would happen if a cell replicated once in the presence of this radioactive base? A. One of the daughter cells, but not the other, would have radioactive DNA. B. Neither of the two daughter cells would be radioactive. C. All four bases of the DNA would be radioactive. D. DNA in both daughter cells would be radioactive. E. Only the RNA would be radioactive in the daughter cells.
D. DNA in both daughter cells would be radioactive.
100
HIV is what type of virus?
Retrovirus
100
The DNA double helix is antiparallel. This means that _________. A. the sugar-phosphate backbones of the two strands run in opposite directions B. the 5’→3’ direction of one strands runs counter to the 3’→5’ direction of the other strand C. the bases of one strand are not parallel to the bases of the other strand D. both A and B E. A, B, and C
D. both A and B
200
How would one explain a testcross involving F1 dihybrid flies in which more parental-type offspring than recombinant-type offspring are produced? A. The two genes are linked. B. The two genes are unlinked. C. Recombination did not occur in the cell during meiosis. D. The testcross was improperly performed. E. Both of the characters are controlled by more than one gene.
A. The two genes are linked.
200
Two possible results of chromosomal breakage is for a fragment to join a nonhomologous chromosome which is called ________, or for a fragment to reattach to the original chromosome but in the reverse orientation, which is called ________. A. translocation …………… inversion B. disjunction …………… inversion C. inversion …………… translocation D. inversion …………… disjunction E. deletion …………… disjunction
A. translocation …………… inversion
200
A particular eukaryotic protein is 300 amino acids long. What is the minimum number of nucleotides in the DNA that codes for the amino acids in this protein? A. 3 B. 100 C. 300 D. 900 E. 1,800
D. 900
200
Which enzyme must accompany HIV genetic material in order to insert its genome into the host genome?
Integrase
200
Watson and Crick proposed that the DNA molecule could carry a vast amount of hereditary information in its _____. A. sequence of bases B. sugar-phosphate backbone C. complementary pairing of bases D. different five-carbon sugars E. side groups of nitrogenous bases
A. sequence of bases
300
A couple has three children, all with 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 E. 1
D. 1/2
300
In comparing nuclear DNA with mitochondrial or chloroplast DNA, which of the following is false? A) Mitochondrial and chloroplast DNA do not cross-over as nuclear DNA does. B) Mitochondrial and chloroplast DNA originate as nuclear DNA that migrates from the nucleus after fertilization into their respective organelle. C) Mitochondrial and chloroplast DNA are maternally inherited, while nuclear DNA is inherited from both maternal and paternal gametes. D) Mitochondrial and chloroplast DNA have higher mutation rates then nuclear DNA. E) None of the above, all the statements are true.
B) Mitochondrial and chloroplast DNA originate as nuclear DNA that migrates from the nucleus after fertilization into their respective organelle.
300
What is the amino acid sequence of the protein coded by this mRNA sequence? 5’ CAG UUA GCA 3’ A) N— Ala Leu Gln —C B) N— Gln Leu Ala —C C) N— Thr Val Asp —C D) N —Asp Val Thr — C E) N —Gln Ala Leu — C
B) N— Gln Leu Ala —C
300
What is the function of reverse transcriptase?
To use HIV's RNA genome to make DNA that can be integrated into the host genome
300
_____ bonds are found between paired bases of the DNA double helix, and _____ bonds are found between paired bases of codons and anticodons. A. Hydrogen ................. ionic B. Ionic ................. hydrogen C. Covalent ................. hydrogen D. Hydrogen ................. hydrogen E. Ionic ................. ionic
D. Hydrogen ................. hydrogen
400
Gene S controls the sharpness of spines in a cactus. Cacti with the dominant allele, S, have sharp spines, cacti that are homozygous recessive ss have dull spines. A second gene, N, determines whether cacti have spines. Homozygous recessive nn cacti have no spines. The relationship between genes S and N is an example of _____. A. incomplete dominance B. epistasis C. complete dominance D. pleiotropy E. codominance
B. epistasis
400
Where are Barr bodies found? A) in male and female gamete cells B) the nucleus of male somatic cells C) in sperm cells D) the nucleus of female somatic cells E) the nucleus of male and female somatic cells
D) the nucleus of female somatic cells
400
Which of the following statements about DNA polymerase and RNA polymerase is false? A) Both DNA and RNA polymerase add nucleotides to free 3' ends. B) Both DNA and RNA polymerases use a DNA strand as a template. C) RNA polymerase, but not DNA polymerase, can initiate synthesis of a polynucleotide without a primer. D) DNA polymerase can elongate in both the 5’ to 3’ direction and in the 3’ to 5’ direction. E) None of the above, all the statements are true.
D) DNA polymerase can elongate in both the 5’ to 3’ direction and in the 3’ to 5’ direction.
400
A virus's envelope and glycoproteins are derived from
the host
400
A dihybrid cross resulting in a phenotypic ratio of 9:3:3:1 is characteristic of ________. A) epistasis B) complete dominance C) codominance D) incomplete dominance E) polygenic inheritance
B) complete dominance
500
Which of the following statements is applicable to the law of independent assortment? A) Genes are found in DNA and not in the proteins in chromosomes. B) The alleles of different characters segregate during gamete formation without influence of the other. C) The two alleles for a character are separated into different gametes. D) Applies to genes that are on the same chromosome. E) All of the above statements are true and apply to independent assortment.
B) The alleles of different characters segregate during gamete formation without influence of the other.
500
Recombination can occur due to ___________. A) independent assortment of genes during meiosis B) crossing over between homologous chromosomes during prophase I C) incomplete dominance D) epistasis E) both A and B
E) both A and B
500
Choose the answer that has these events of protein synthesis in the proper sequence. 1. Ribosome shifts mRNA one codon as tRNA with polypeptide moves from A to P site. 2. A small ribosomal subunit binds with mRNA. 3. A release factor binds to the A site. 4. Peptide bond formation between amino acid in A site and polypeptide in P site. 5. Codon/anticodon recognition results in aminoacyl-tRNA binding to A site. A. 2, 4, 5, 3, 1 B. 2, 4, 5, 3, 1 C. 4, 5, 2, 1, 3 D. 2, 5, 4, 1, 3 E. 3, 1, 4, 5, 2
D. 2, 5, 4, 1, 3
500
List the steps of HIV's life cycle ~10 steps
1. glycoproteins recognize receptors on immune cells 2. virus enters, the capsid is degrated 3. RNA is transcribed by reverse transcriptase 4. second DNA transcribed (host genome is ds) 5. DNA incorporated into host genome by integrase 6. DNA transcribed into mRNA (normal transcription) 7. mRNA translated to produce host protein AND viral proteins 8. vesicles transported to cell surface carrying viral proteins 9. budding of new virus 10. virus exits host cell
500
How is incomplete dominance distinguished from codominance? A) A cross of heterozygotes produces a 1:2:1 phenotypic ratio in incomplete dominance and a 3:1 ratio in codominance. B) The heterozygote in codominance has a distinct phenotype from the two homozygotes, while in incomplete dominance the heterozygote exhibits both phenotypes of the homozygote simultaneously. C) The heterozygote with incomplete dominance has a distinct phenotype from the two homozygotes, while in codominance the heterozygote exhibits both phenotypes of the two homozygotes simultaneously. D) A cross of heterozygotes produces a 3:1 phenotypic ratio with incomplete dominance, and a 1:2:1 ratio in codominance.
C) The heterozygote with incomplete dominance has a distinct phenotype from the two homozygotes, while in codominance the heterozygote exhibits both phenotypes of the two homozygotes simultaneously.