1. Mitochondria and chloroplasts have their own genetic systems, which: A. conta
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Question
1. Mitochondria and chloroplasts have their own genetic systems, which:
A. contains a single linear chromosome with a centromere.
B. directs synthesis of both organelle and cytoplasmic proteins.
C. includes genes that encode ribosomal RNAs and ribosomal proteins.
D. is inherited exclusively from the male gamet
2. What advantage is conferred to multicellular organisms by the presence of repetitious DNA, which has been called "junk" DNA, in the genome?
It promotes mRNA splicing.
It promotes chromosomal translocations, which allows adaptation and evolution.
It promotes recombination, which allows adaptation and evolution.
It promotes correction of mutations that accumulate during DNA replication.
3. Which of the following are properties of heterochromatin?
all are correct.
in an electron microscope image, is a light-staining area of a chromosome.
is a region of condensed chromatin.
contains DNA that is frequently transcribed into RNA.
4. Which of the following is (are) functional element(s) of a eukaryotic chromosome?
(select all that apply)
Nucleolus
Telomere
Centromere
Origin of replication
5. Which of the following is (are) true about a nucleosome:
(select all that apply)
is about 10 micrometers in diameter.
is more likely to be found in beads-on-a-string chromatin structure than in condensed chromatin
contains approximately 147 base pairs of DNA.
6. You extract a mammalian cell culture sample to prepare total nucleic acids (DNA + RNA). Using this preparation, you produce complementary DNA (cDNA) by treating the nucleic acid preparation with reverse transcriptase, using oligo(dT) as the primer, in the presence of all four dNTPs. Using an aliquot of the cDNA as template, you then perform PCR using 2 primers that should amplify a DNA segment of 500 bp, based on the known sequence of the mRNA for this gene, which is transcribed from a simple transcription unit. When you electrophorese the PCR reaction on a 1% agarose gel, you do indeed observe a 500 bp product as expected. However, you also observe a 750 bp product. What could explain these results?
A. The target gene has a high proportion of G-C nucleotides in its sequence, which produces strong secondary structure in the mRNA.
The oligo(dT) primer used to prime the reverse transcription reaction annealed with an oligo(A) sequence in the coding sequence a non-target mRNA.
The primers were not specific for the target gene and also amplified a segment of cDNA from another gene.
Because genomic DNA was present in the total NA preparation, in addition to the expected 500 bp product, the PCR amplified a segment containing an intron lying between 2 exons.
A. contains a single linear chromosome with a centromere.
B. directs synthesis of both organelle and cytoplasmic proteins.
C. includes genes that encode ribosomal RNAs and ribosomal proteins.
D. is inherited exclusively from the male gamet
Explanation / Answer
1. C. includes genes that encode ribosomal RNAs and ribosomal proteins.
2. D. It promotes correction of mutations that accumulate during DNA replication.
3. C. is a region of condensed chromatin.
4. B. Telomere
C. Centromere
D. Origin of replication
5. B. contains an octamer core of histones.
C. is more likely to be found in beads-on-a-string chromatin structure than in condensed chromatin.
D. contains approximately 147 base pairs of DNA.
6. Because genomic DNA was present in the total NA preparation, in addition to the expected 500 bp product, the PCR amplified a segment containing an intron lying between 2 exons.
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