TLS Online TPP Program

#Question id: 7178


In sea urchin, the large micromeres are autonomously specified. They inherit maternal determinants that were deposited at the vegetal hemisphere of the egg; these become incorporated into the large micromeres at fourth cleavage. When an isolated animal hemisphere is combined with isolated micromeres, then what will be the result?

#Unit 5. Developmental Biology
  1. A recognizable pluteus larva is formed, with all the endoderm derived from the animal hemisphere.
  2. Animal hemisphere becomes a ciliated ball of undifferentiated ectodermal cells.
  3. Micromeres differentiate into skeletal rods while the induced animal cap cells to form ectoderm.
  4. The vegetal cell fates are not specified, and the entire embryo develops as a ciliated ectodermal ball.
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TLS Online TPP Program

#Question id: 4400

#Unit 3. Fundamental Processes

Which is the first factor to bind at the promoter of eukaryotic genes?

a. RNA polymerase

b. TFIIA

c. TFIIB

d. TFIID 

e. TATA box–binding protein

TLS Online TPP Program

#Question id: 4401

#Unit 3. Fundamental Processes

Which of the following occur(s) during Pol II transcription preinitiation complex formation?

a. TFIIA binds to TFIIB.  b. TFIIB unwinds the DNA.

c. TFIIB contacts both TATA box–binding factor and DNA.

d. DNA bends.

TLS Online TPP Program

#Question id: 4402

#Unit 3. Fundamental Processes

Chromatin-mediated repression of transcription involves

a. modification of lysine residues in histones. 

b. large, multiprotein complexes.

c. acetylation of histone tails.   

d. deacetylation of histone tails.

TLS Online TPP Program

#Question id: 4403

#Unit 3. Fundamental Processes

 Which of the following does (do) not require a DNA helicase activity?

a. SWI/SNF function  b. Pol II open-complex formation

c. transcription-factor binding to DNA

d. deacetylation of histone tails

TLS Online TPP Program

#Question id: 4404

#Unit 3. Fundamental Processes

The yeast two-hybrid system can be used to identify

a. proteins that interact with a known or “bait” protein.

b. proteins that interact with a “fish” domain.

c. cDNAs that encode interacting proteins.

d. co-activators and co-repressors.

TLS Online TPP Program

#Question id: 4405

#Unit 3. Fundamental Processes

Which of the following can occur when steroid hormone binds to its cognate receptor?

a. conformational changes in the receptor

b. translocation of the receptor out of the cell membrane

c. binding of the receptor to DNA response elements

d. stimulation of transcription