TLS Online TPP Program

#Question id: 7201


Many of the cell and tissue movements in Xenopus gastrulation happen simultaneously. Still identify the different types of behaviors that occur during Xenopus gastrulation:

A. Epiboly: The thinning and spreading of the animal cap cells over the vegetal hemisphere, powered by proliferation and radial intercalation.

B. Vegetal rotation: Vegetal cells asymmetrically press up against the inner blastocoel roof on the dorsal side.

C. Bottle cell formation and invagination: The leading edge of invaginating cells crawls up onto the blastocoel roof.

D. Involution and cell migration: Localized apical constriction at the dorsal blastopore lip creates anisotropic forces that foster invagination.

E. Convergence and extension: The targeted medial-to-lateral intercalation of cells on the midline (convergence) drives anterior-posterior axis elongation (extension).

Which of the following definition are correct according to their process?

#Unit 5. Developmental Biology
  1. A and B only
  2. A, C and D
  3. A, B and E
  4. C and D only
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TLS Online TPP Program

#Question id: 4700

#Unit 11. Evolution and Behavior

Which of the following is not an observation or inference on which natural selection is based?

TLS Online TPP Program

#Question id: 4701

#Unit 11. Evolution and Behavior

Charles Darwin discussed all of the following EXCEPT:

TLS Online TPP Program

#Question id: 4702

#Unit 11. Evolution and Behavior

Which of the following is correct match?

TLS Online TPP Program

#Question id: 4703

#Unit 11. Evolution and Behavior

Within a few weeks of treatment with the drug 3TC, a patientʹs HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?

TLS Online TPP Program

#Question id: 4704

#Unit 11. Evolution and Behavior

About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?

TLS Online TPP Program

#Question id: 4705

#Unit 11. Evolution and Behavior

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ________.