DNA structure and the meselson-stahl experiment
In any given DNA molecule, the amount of ______ is equal to the amount of ______
a. cytosine bases, thymine bases
b. nucleotides, hydrogen bonds
c. purines, pyrimidines
Answer:
c. purines, pyrimidines
what is the difference between a chromatid and an unreplicated chromosome?
a. nothing, they are the same thing
b. a chromatid is the replicated version of a chromosome
c. a chromatid is a half of a chromosome
Answer:
a. nothing, they are the same thing
refer to slide 21 on the final exam powerpoint
True or false:
1 nonhomologous chromosome us inherited from each parent
Answer:
false, 1 homologous chromosome is inherited from each parent
mitosis occurs in _______ cells; meiosis occurs in _______ cells
a. germ line, somatic
b. somatic, germ line
c. haploid, diploid
Answer:
b. somatic, germ line
the implications of the law of segregation can be seen in what type of crosses? what about the law of independent assortment?
Answer:
monohybrid crosses
dihybrid crosses
DNA is composed of nucleotides. What are the three components that make up a nucleotide?
Answer:
1.Deoxyribose sugar
2.Phosphate group located on the 5 prime carbon
3.Nitrogenous base located on the 1 prime carbon (ATGC)
If we started the G1 phase of the cell cycle with 30 DNA molecules, how many DNA molecules would we have once we got to the G2 phase?
a. 15
b. 30
c. 60
d. 32
Answer:
d. 60 DNA molecules
because from the G1 to G2 phase, the S phase takes place where DNA is replicated
True or false:
homologous chromosomes hold the same genes in the same locations
Answer:
true
The ______ of homologous chromosomes occurs during prophase of meiosis I.
a) pairing
b) random alignment
c) separation
d) replication
Answer:
A. pairing
DNA was found to be replicated ________
a. semiconservatively
b. dispersively
c. conservatively
Answer:
a. semiconservatively
If we begin mitosis with 500 DNA molecules, how many DNA molecules will we have by the end of mitosis?
a. 150
b. 500
c. 502
d. 250
d. 250
because by the end of mitosis the original number of DNA molecules has been halved for the two identical daughter cells
the diploid (2n) number represents that we have two copies of _______ chromosomes; the haploid (n) number represents that we have one copy of ______ chromosomes
a. nonhomologous, homologous
b. homologous, nonhomologous
Answer:
b. homologous, nonhomologous
look at your note packets for unit 5 section 1
During which phase of meiosis 1 does independent assortment occur?
a. prophase
b. metaphase
c. anaphase
d. telophase
Answer:
b. metaphase
The meselson-stahl experiment first grew bacteria in a medium containing a ______ isotope of nitrogen and then switched to a ______ isotope of nitrogen
a. 15N heavy, 14N light
b. 15N light, 14N heavy
c. 16N heavy, 13N light
Answer:
a. 15N heavy, 14N light
what occurs during anaphase of the cell cycle?
Answer:
sister chromatids are separated and the sister chromatids are pulled toward opposite poles of the cell
what is the difference between sister chromatids and non sister chromatids?
Answer:
sister chromatids are part of the same replicated chromosome, non-sister chromatids is the relationship between chromatids from homologous chromosomes
refer to unit 5 section 1 notes
Mutations have to occur in ______ cells in order for them to be passed onto other generations
Answer:
germ line cells (sperm and egg)
what is the cell checking for during the G2 checkpoint?
Answer:
ensures all of the chromosomes have been replicated and that the replicated DNA is not damaged before cell enters mitosis