The nodes on a phylogenetic tree represent:
A. common ancestors.
B. descendant lineages.
C. sister groups.
D. present-day groups.
E. homologies.
A
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When entering a newly generated DNA sequence into the Basic Local Alignment Search Tool (BLAST), a researcher can:
A. identify orthologs. B. assign tentative function to a protein. C. identify restriction enzyme sites. D. identify orthologs and assign tentative function to a protein. E. identify orthologs and identify restriction enzyme sites.
Which of the following functions does the stomach perform the LEAST? a. absorption b. digestion c. storage d. mixing e. movement
You discovered an unidentified weed and cut it almost to the ground with the lawn mower. Soon it grows as tall as it was before you cut it. This growth is likely due to which growth region?
A) Shoot apical meristem B) Root apical meristem C) Vascular cambium D) Lateral bud meristem E) Cork cambium
You are interested in studying kinesin movements. You therefore prepare silica beads and coat them with kinesin molecules so that each bead, on average, has only one kinesin molecule attached to it. You add these kinesin-coated beads to a preparation of microtubules you have polymerized. Using video microscopy, you watch the kinesin [labeled with green fluorescent protein (GFP)] move down the
microtubules.
A. Kinesin-GFP has been measured to move along microtubules at a rate of 0.3 ?m/sec, and single-molecule studies have revealed that kinesin moves along microtubules progressively, with each step being 8 nm. How many steps can the kinesin molecule take in 4 seconds, assuming that the kinesin stays attached to the microtubule for the entire 4 seconds?
B. Because each kinesin molecule is thought to take approximately 100 steps before falling off the microtubule, will you see your silica beads detach from the microtubule during your 4 seconds of observation?
C. What would you predict would happen to the kinesin-coated silica beads if you were to add AMP-PNP (a nonhydrolyzable ATP analog)?