Flashcards in Exam 1 Deck (49)
In an organism with a diploid number of 8, a gamete has _______ chromosomes, a liver cell has _______ chromosomes, and a sperm cell at meiotic anaphase I has _______ chromosomes.
A) 8; 8; 8
B) 8; 4; 8
C) 8; 4; 4
D) 4; 8; 8
E) 4; 4; 4
D. 4: 8; 8
The transcription initiation site is located
A) within the promoter.
B) on RNA polymerase.
C) at splice sites.
D) in a ribosome.
E) None of the above
A. within the promoter
Termination of transcription involves a
A). stop codon
B). terminator sequence
D). hairline slip
E). series of As
B. terminator sequence
Mendel's crossing of spherical-seeded pea plants with wrinkled-seeded pea plants resulted in progeny that all had spherical seeds. This indicates that the wrinkled-seed trait is
D) Both a and b
E) Both a and c
A deoxyribonucleoside is a
A) deoxyribose plus a nitrogenous base.
B) sugar and a phosphate.
C) deoxyribose plus a nitrogenous base and a phosphate.
D) ribose plus a nitrogenous base.
E) nitrogenous base bonded at the 5′ end to a sugar–phosphate backbone.
A. deoxyribose plus a nitrogenous base
A pea plant with red flowers is test crossed, and one-half of the resulting progeny have red flowers, while the other half has white flowers. Therefore, the genotype of the test-crossed parent was
D) either RR or Rr.
E) This cannot be answered without more information.
Meiosis can occur
A) in all sexually reproducing organisms.
B) only when an organism is diploid.
C) only in multicellular organisms.
D) only in haploid organisms.
E) only in single-celled organisms.
A. in all sexually reproducing organisms
Refer to the following diagram of DNA complementary base pairing. Which of the following bases would pair (from top to bottom) with the exposed 3′-end strand?
B. TCGA (opposite of the base pair on the 3' strand
A strand of DNA with the sequence 5′-ATTCCG-3′ would have a complementary strand with the sequence
DNA replication occurs
A) during both mitosis and meiosis.
B) only during mitosis.
C) only during meiosis.
D) during S phase.
E) Both A and D
E. Both A and D
In all sexually reproducing organisms, the diploid phase of the life cycle begins at
A) spore formation.
B) gamete formation.
Asexual reproduction produces genetically identical individuals because
A) chromosomes do not have to replicate during asexual reproduction.
B) it involves chromosome replication without cytokinesis.
C) no meiosis or fertilization takes place.
D) cell division occurs only in meiosis.
E) the mitotic spindle prevents nondisjunction.
C. no meiosis or fertilization takes place
The DNA of a eukaryotic cell is
D) complex inverted.
Cells that do not divide are usually arrested in
The process by which information in the nucleic acid sequence is used to direct the production of a specific chain of amino acids is called
E) None of the above
Which of the following molecules are contained in a spliceosome?
A) DNA and RNA
B) DNA and protein
C) RNA and protein
D) RNA and lipid
E) Protein and lipid
C. RNA and protein
How does a nucleus in G2 differ from a nucleus in G1?
A)The G2 nucleus has twice the amount of DNA as the G1 nucleus.
B) DNA synthesis occurs only in G1 phase.
C) Inactive cells are arrested only in G2 phase.
D) During G2, the cell prepares for S phase.
E) All of the above
A. The G2 nucleus has twice the amount of DNA as the G1 nucleus
If two strains of true-breeding plants that have different alleles for a certain character are crossed, their progeny are called
A) the P generation.
B) the F1 generation.
C) the F2 generation.
D) F1 crosses.
E) F2 progeny.
B. the F1 generation
The microtubules of the mitotic spindle attach to a specialized structure in the centromere region of each chromosome called the
C) equatorial plate.
Microtubules that form the mitotic spindle tend to originate from or terminate in
A) centromeres and telomeres.
C) centrioles and telomeres.
D) the nuclear envelope.
E) centrioles and kinetochores
E. centrioles and kinetochores
Chargaff's rule states that
A) DNA must be replicated before a cell can divide.
B) viruses enter cells without their protein coat.
C) only protein from the infecting phage can also be detected in progeny phage.
D) only nucleic acids enter the cell during infection.
E) the amount of cytosine equals the amount of guanine.
E. the amount of cytosine equals the amount of guanine.
If a trait that is not expressed in the F1 generation reappears in the F2 generation, the inheritance of the trait in question is an example of
B) dominance and recessiveness.
C) incomplete dominance.
E) a test cross.
B. dominance and recessiveness
Which of the following molecules functions to transfer information from one generation to the next in eukaryotes?
Semiconservative replication of DNA involves
A) each of the original strands acting as a template for a new strand.
B) only one of the original strands acting as a template for a new strand.
C) the complete separation of the original strands, the synthesis of new strands, and the reassembly of double-stranded molecules.
D) the use of the intact double-stranded molecule as a template.
E) None of the above
A. each of the original strands acting as a template for a new strand
Separation of the alleles of a single gene into different gametes is called
C) independent assortment.
D) heterozygous separation.
The strands that make up DNA are antiparallel. This means that
A) one strand is positively charged, and the other is negatively charged.
B) the base pairings create unequal spacing between the two DNA strands.
C) the 5′-to-3′ direction of one strand is counter to the 5′-to-3′ direction of the other strand.
D) the twisting of the DNA molecule has shifted the two strands.
E) purines bond with purines and pyrimidines bond with pyrimidines.
C. the 5′-to-3′ direction of one strand is counter to the 5′-to-3′ direction of the other strand
A mutant strain of yeast grew well at 20°C, but not at 37°C, whereas the wild-type strain grew well at both temperatures. The mutation is an example of a
A) conditional mutation.
B) missense mutation.
C) point mutation.
D) frame-shift mutation.
E) gain-of-function mutation.
A. conditional mutation
Mendel concluded that each pea has two units for each character, and each gamete contains one unit. Mendel's “unit” is now referred to as a(n)
D) transcription factor.
E) None of the above
The genotype of an organism that expresses a dominant trait can be determined by
A) crossing the organism with a homozygous dominant organism.
B) crossing the organism with a heterozygous dominant organism.
C) crossing the organism with a homozygous recessive organism.
D) observing the phenotype of the progeny from any cross.
E) observing the genotype of the progeny from any cross.
C. crossing the organism with a homozygous recessive organism.