exam 3 flashcards
If a cell contained a mutation in the gene that encodes FtsZ, which process would affected?
Septation
Crossing over between homologous chromosomes takes place during
Prophase I
As the two strands of DNA are unraveled, which enzyme relieves the strain on the two strands?
DNA gyrase
In bacterial cell division, the cell divides into two nearly equal halves. This process is referred to as:
binary fission
This protein or protein complex functions in the cell to stop cell division if the cell has experienced extensive DNA damage:
p53
Nucleotides have a phosphate group attached at the ____ carbon atom of the sugar.
5’
If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes?
32
A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle?
S phase
In what portion of the cell cycle do the chromosomes appear invisible under a light microscope because they are not yet condensed?
Interphase
What stage of mitosis is essentially the reverse of prophase?
Telophase
During DNA replication, DNA polymerase III or DNA polymerase delta synthesizes lagging strand in segments, called
Okazaki fragments
Which enzyme adds new nucleotides to the end of a growing strand?
Polymerase
Based on their experiment with bacteriophages (and blenders), Hershey and Chase concluded that
____ functions as the _______ __________.
DNA functions as the genetic material
A codon is composed of how many bases?
3
Watson and Crick developed a model of DNA in which the two strands twist into the shape of a ______ ______.
double helix
In animals, the cells that will eventually undergo meiosis to produce gametes are set aside early in development. These are called
germ-line cells
_______ cells contain one set of chromosomes
Haploid
This stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decompensation of the chromosomes:
Telophase
_______ is process of nuclear division that reduces the number of chromosomes per cell from 2 sets to 1 set.
Meiosis
During this stage of mitosis, the nuclear envelope begins to break down and the spindle begins to form.
Prophase
A scientist wants to study histones. Histones are
a) proteins that double-stranded DNA molecules wrap around in eukaryotes.
b) proteins that double-stranded DNA molecules wrap around in prokaryotes and eukaryotes
c) proteins that regulate checkpoints in the mitotic cell cycle
d) proteins that serve as the spindle fiber to pull sister chromatids apart during anaphase
e) proteins that required for the activity of Cdk enzymes
A
You are studying meiosis in an organism where 2n=24. How many chromosomes will each nucleus have after meiosis II is complete?
12
Which cells never divide by meiosis? (3)
a) Haploid cells
b) Diploid cells
c) Somatic cells
d) Germ-line cells
e) Zygotes
haploid cells, somatic cells, zygotes
Interphase is made up of what stages of the cell cycle?
a) G1 + G2 + S
b) S + cytokinesis
c) prophase + metaphase + anaphase + telophase
d) cytokinesis + mitosis
e) G0 + G1 + G2
a) G1 + G2 + S
The sequence of nucleotides in a DNA molecule is called the _____ code.
genetic
According to Chargaff’s rules about proportions of nitrogenous bases,
A=T and G=C
During translation, amino acids are carried to the ribosome by
tRNA
DNA primase
a) creates a short RNA primer that is complementary to an RNA template
b) creates a short DNA primer that is complementary to an RNA template
c) creates a short DNA primer that is complementary to a DNA template
d) creates a short DNA template that is complimentary to an RNA primer
e) creates a short RNA primer that is complementary to a DNA template
e) creates a short RNA primer that is complementary to a DNA template
Which structures indicate where crossing over has occurred?
Chiasmata
Which events occurs first during meiosis?
Sypnapsis of homologous chromosomes
Animal cells typically achieve cytokinesis by
forming a cleavage furrow that pinches the cell into two