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TLS Online TPP Program

#Question id: 799

The two cleavage reactions required to generate the miRNA from these primary transcripts are mediated by two distinct RNases. A characteristic of both these enzymes is that they recognize and cleave RNAs on the basis of the structure of their substrates rather than their specific sequence. Which of the following statement is INCORRECT regarding the cleavage reactions that produces a mature RNA?

#SCPH05 I Biotechnology

  1. Drosha resides in the cell’s nucleus, and the Drosha-catalyzed cleavage event occurs in that cellular compartment that generates a pre-miRNA which is ~65–70 nucleotides long.

  2. The pre-miRNA liberated by Drosha is exported to the cytoplasm, where the second RNA cleavage reaction, performed by Dicer, takes place which cleaves pre-miRNA 22 nucleotides from its ends.

  3. For processing by Drosha, ssRNA lacking significant secondary structure, is needed flanking each side (5’ and 3’) of the stem-loop. It is the ssRNA–dsRNA junctions that are in responsible for determining the cleavage specificity of Drosha.

  4. The RNase II family enzymes are specific for dsRNA and cleave it in a manner that leaves a 2-nucleotide overhang on the 3’ ends of the dsRNA product. This 3’ overhang is important for recognition of that RNA molecule by the next enzyme in the pathway, Dicer.

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TLS Online TPP Program

#Question id: 8697

#SCPH28 | Zoology

Use the figure to answer the following question.

Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in the figure?
TLS Online TPP Program

#Question id: 8698

#SCPH06 I Botany

Use the figure to answer the following question.

If the figure above is an accurate depiction of relatedness, then which of the following should be an accurate statement?
TLS Online TPP Program

#Question id: 8698

#SCPH28 | Zoology

Use the figure to answer the following question.

If the figure above is an accurate depiction of relatedness, then which of the following should be an accurate statement?
TLS Online TPP Program

#Question id: 8699

#SCPH06 I Botany

Use the figure to answer the following question.

If the figure is an accurate depiction of relatedness, then which of the following should be an accurate statement?
TLS Online TPP Program

#Question id: 8699

#SCPH28 | Zoology

Use the figure to answer the following question.

If the figure is an accurate depiction of relatedness, then which of the following should be an accurate statement?
TLS Online TPP Program

#Question id: 8700

#SCPH06 I Botany

Use the following figure and description to answer the question.

Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 15 million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes ________.