BIO Exam 3
Accuracy in translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________.
attachment of amino acids to tRNAs
Which of the following types of pathogenic prokaryotes cause cholera?
bacteria that release an exotoxin
Which of the following statements correctly describes a process by which bacteria become resistant to antibiotics?
conjugation spreads antibiotic resistance genes rapidly in a population
The primary growth of a plant adds __________, and secondary growth adds __________.
height, thickness
Dr. Russell saw this Ohio Spiderwort on his way into school. You were very impressed and you relocated the plant after school. You were not surprised to find it had
leaf veins forming a parallel pattern and six stamens
Which of the following molecules directly participates in the process of translation?
mRNA, tRNA, and rRNA
The complete chromosome of a bacterium is found in the __
nucleoid
The procambium gives rise to
primary xylem, phloem and some residual meristematic cells
Which of the following plant parts absorbs most of the water and minerals taken up from the soil?
root hairs
A major difference between sclerenchyma and collenchyma cells is ?
sclerenchyma are specialized dead cells
Which of the following statements is the most likely result of conjugation involving a bacterium that contains a copy of a plasmid containing a gene for tetracycline resistance with one that does not ?
the rapid spread of tetracycline resistance to the other bacteria in the population
If all prokaryotes on Earth suddenly vanished, which of the following would be the most likely and most direct result?
the recycling of nutrient would be greatly reduced
How do cells in a meristem differ from cells in other types of plant tissue?
they continue to divide
The capacity of a single parenchyma cell to regenerate into an entire plant is called
totipotency
Which of the following are water-conducting cells that are dead at functional maturity?
tracheids and vessel elements
Which of the following processes leads to genetic recombination by the introduction of viral DNA into a bacterium?
transduction
Cell division in the vascular cambium adds to the circumference of a tree trunk and the diameter of roots and stems by adding new __________ to the layer's interior and __________ to the layer's exterior.
xylem, phloem
Secondary growth
-lateral meristem -cork cambrium -growth in thickness -provides structural support -vascular cambrium -increases vascular flow
Which of the following molecular structures contains codons? -tRNA -rRNA -mRNA -a protein
-mRNA
both primary and secondary growth
-occurs in plants that live many years
Primary growth
-occurs in plants that live only one year -increases exposure to light -elongation -apical meristem
Which of the following structures is needed for the translation initiation complex to form in eukaryotes?
5' cap
A nail is driven (1 meter above ground level) into the trunk of an oak tree. Oak trees grow 1 meter per year. In 4 years (include spring growth in each year), the nail would be
6 feet above ground level
Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs? A. The rules for base pairing between the third base of a codon and tRNA are flexible. B. The DNA codes 61 tRNAs, but some are destroyed after transcription. C. Many codons are never used, so the tRNAs that recognize them are dispensable. D. Some tRNAs have anticodons that recognize four or more different codons
A. The rules for base pairing between the third base of a codon and tRNA are flexible.
Living organisms can be divided into two groups: autotrophs and heterotrophs . How do these two groups differ?
Chemotrophs obtain energy from chemicals and phototrophs obtain energy from light
Which of the following statements correctly describes both phototrophs and chemotrophs?
Chemotrophs obtain energy from chemicals and phototrophs obtain energy from light
Which of the following best describes the redundancy in the genetic code? A. The genetic code is universal (the same for all organisms). B. The genetic code is different for different domains of organisms. C. A single codon can specify the addition of more than one amino acid. D. More than one codon can specify the addition of the same amino acid
D. More than one codon can specify the addition of the same amino acid.
Which of the following statements best describes the termination of transcription in prokaryotes? A. RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA B. Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome and releases. C. RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase D. RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
D. RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
In eukaryotes which of the following is the first step in translation? A.binding of the larger ribosomal subunit to smaller ribosomal subunits B. the ribosome reaches a stop codon C. base pairing of activated methionine-tRNA to AUG of the messenger RNA D. the small subunit of the ribosome recognizes and attaches near the 5' cap of mRNA
D. the small subunit of the ribosome recognizes and attaches near the 5' cap of mRNA
The veins of leaves are best described as which of the following? I) composed of xylem and phloem II) continuous, with vascular bundles in the stem III) finely branched to be in close contact with photosynthesizing cells
I , II, and III
What is the function of the release factor during translation in eukaryotes?
It binds to the stop codon in the A site in place of a tRNA.
You find a plant unfamiliar to you and observe that it has vascular bundles scattered throughout the stem cross section. What should you conclude about the plant?
It is a monocot.
Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes?
It is the recognition site for the binding of a specific transcription factor.
Which of the following cell types is not abundant in a banana?
Parenchyma