HTHS 1110 Unit 6
How many start codons are there? How many stop codons are there?
1 start, 3 stop
For each cell that enters meiosis, ___ daughter cell(s) is/are produced.
4
Cells involved in sexual reproduction are called gametes and have less DNA. All other cells in the body are called somatic cells. How many DNA molecules do quiescent (non-dividing) somatic cells have?
46
DNA sequences are always read:
5' ⟶⟶ 3'
There are four nucleotides used in mRNA (A, C, G, U). Codons have three nucleotides (AAA, AAC, AAG, etc). How many possible codons are there?
64
During replication, in S phase of the cell cycle, the genetic material is duplicated. The different rates of replication between the two strands of the double helix create the leading strand and lagging strand. What enzyme is used to synthesize the leading strand?
DNA polymerase
This diagram shows the process of replication, which involves the synthesis of two new DNA strands from a double-stranded DNA template. The process of replication requires:
DNA polymerase
Jim Brown recently survived a myocardial infarction (heart attack). His doctors informed him that he had lost a portion of his heart muscle, as heart cells don't replicate. Heart muscle cells are most likely found in which phase of the cell cycle?
G0 phase
A karyotype is a technique that allows us to stain, count, and examine chromosomes. Karyotypes are taken from cells in the period marked "9", called
M phase
The small fragments of DNA that are used in replication of the lagging strand, shown at "2", are called
Okazaki fragments
The stop codons are:
UAA, UAG, UGA
Two DNA strands, base-paired to one another in a double helix, are said to run ________________ to each other.
antiparallel
Which process (at "2") describes the active transport mechanism by which a virus enters the eukaryotic cell?
cell engulfs virus by endocytosis
During metaphase, microtubules extend from the centrosome (centriole + pericentriolar material) to the:
centromere
What is the sequence of nucleotides shown at "8"?
codon
The process shown here that results in a mixture of "yellow" and "blue" chromosomal material is called:
crossing over
What happens to DNA when methyl (-CH3) groups are added to it?
genes in the region of DNA methylation are turned off
The __________ describes the makeup of DNA, but not necessarily observable characteristics.
genotype
The process shown at "B" might occur in which cells of an adult?
germ cells (eggs and sperm)
DNA is packaged into chromosomes by wrapping it around proteins called:
histones
The structure shown as "4" is:
histones
This diagram shows DNA (black line) looped around light blue protein molecules. These proteins are called:
histones
These regions are "edited out" in the processing of the initial RNA transcript. Once they are removed, the remaining molecule is called messenger RNA.
introns
The structure shown at "4" is:
large ribosomal subunit
The process shown that starts at "B" and ends at "C" is:
meiosis
The segment of mitosis shown as "2" is:
metaphase
What is the molecule marked "5"?
methionine
Consult the codon table. The codon 5'-AUG-3' codes for:
methionine (start)
This process (at "5") describes the departure of new virions from the host cell.
new viral particles made and released into extracellular fluid
The structures diagrammed here at "2" are the:
nuclear pores
If we were to isolate the organelle shown at "1", it would be made primarily of:
nucleic acids and protein
Which structure is labeled "3"?
nucleolus
The structure shown as "3" is:
nucleosome
The structure shown at "2" is the:
p arm
The __________ describes observable characteristics of the organism, but not necessarily the DNA sequence.
phenotype
During almost all of interphase, no chromosomes are visible. What is the first part of mitosis, when chromosomes first condense into recognizable forms?
prophase
The segment of mitosis shown as "1" is:
prophase
The structure shown at "4" is the
q arm
An organelle called a ____________ is responsible for the process at "2."
ribosome
The structure shown at "2" is:
small ribosomal subunit
The backbone of the DNA molecule consists of:
sugars and phosphates alternating
The final step in mitosis is:
telophase
The diagram shows what molecular biologists call:
the Central Dogma
The process at "1" is called:
transcription
The process in which structures "4", "5" and "6" are involved is:
translation
This diagram shows that when methyl groups are attached to histones, the genes in that region are:
turned off
This diagram shows that when acetyl groups are attached to histones, the genes in that region are:
turned on
In the disease sickle cell anemia, a single codon 5'-GAG-3' is mutated to 5'-GUG-3'. This changes glutamic acid in the primary sequence of the hemoglobin molecule to:
valine
Step 1 is:
virus becomes attached to target cell