Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55546
TLS Online TPP Program

#Question id: 5670

Embryonic stem cells can be induced in the laboratory to differentiate into muscle, nerve, pancreatic, and other specialized cell types. It has recently become possible to trigger the dedifferentiation of somatic cells back into pluripotent cells (so-called induced pluripotent stem cells or iPS cells) by artificially enhancing the production of a relatively small number of key transcriptional factors known to be required for maintenance of pluripotency. Examples of such transcription factors are OCT4 and NANOG. The production of OCT4 and NANOG (and other key regulatory proteins) is stimulated by a transcription factor known as FOXP1, a member of the Forkhead family of DNA-binding proteins. There are two isoforms of FOXP1.

Which of the following statement regarding to FOXP1 is incorrect?

#Unit 5. Developmental Biology

  1. The protein encoded by the exon 18b–carrying mRNA is called FOXP1-ES: this activates genes (OCT4, NANOG, etc.) that promote dedifferentiation, and thus stimulates iPS cell formation.

  2. In the exon 18a–containing form encodes FOXP1 itself, and this has the opposite effect: it fails to stimulate expression of OCT4 and NANOG and instead actives genes that promote differentiation.

  3. FOXP1 binds to DNA via a domain known as a Winged helix, which recognizes a particular DNA sequence.

  4. The switch from exon 18a to exon 18b substitutes 3 residues in the Winged helix region of the protein including six amino acids that are known to contact DNA.

More Questions
TLS Online TPP Program

#Question id: 12102

#Unit 10. Ecological Principles

Use the following diagram of Joseph Connell's study of barnacle distribution in Scotland to answer the following two questions


Which of the following is the most logical conclusion about the distribution of the two species of barnacle, Chthamalus and Balanus?
TLS Online TPP Program

#Question id: 12104

#Unit 10. Ecological Principles

Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation?
TLS Online TPP Program

#Question id: 12105

#Unit 10. Ecological Principles

A species of fish is found to require a certain water temperature, a particular oxygen content of the water, a particular depth, a rocky substrate on the bottom, and a variety of nutrients in the form of microscopic plants and animals to thrive. These requirements describe its 
TLS Online TPP Program

#Question id: 12107

#Unit 10. Ecological Principles

As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory, their offspring behave in the same manner. You have discovered an example of
TLS Online TPP Program

#Question id: 4932

#Unit 10. Ecological Principles

Which of the following is the best hypothesis regarding origins of nucleic acids?
TLS Online TPP Program

#Question id: 27686

#Unit 10. Ecological Principles

Which of the following factors are involved to determine the realized niches of organisms?