TLS Online TPP Program

#Question id: 5691


Which of the following most accurately explains the cause for the abnormal numbers of chromosomes during human reproduction that can result in Down syndrome, Turner’s syndrome, or Klinefelter’s syndrome?

#Unit 8. Inheritance Biology
  1. The occurrence of nondisjunction of homologous chromosomes during meiosis

  2. The duplicative production of extra chromosomes during DNA replication

  3. The abnormal pairing of nonhomologous chromosomes during prophase of meiosis I

  4. The selective loss of particular chromosomes from the sex cells after formation of the mature gamete

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TLS Online TPP Program

#Question id: 2976

#Unit 2. Cellular Organization

Match the following Regulators with its functions.

Column I

Column II

A.  Wee1 kinase

i. Degradation of phosphorylated Sic1 or p27KIP1

B. Cdc25A phosphatase

ii. Induces degradation of B-type cyclins

C. APC/CCdc20

iii. Activates vertebrate S phase CDKs

D. SCF

iv. Inhibits CDKs

Which of the following is correct?

TLS Online TPP Program

#Question id: 2975

#Unit 2. Cellular Organization

Following statements are regarding to the Surveillance mechanisms in cell cycle regulation.

A. Surveillance mechanisms known as checkpoint pathways establish dependencies among cell cycle events and ensure that the next cell cycle event does not occur prior to the completion of a preceding event.

B. In response to DNA damage, two related protein kinases, ATM and ATR, are recruited to the site of the damage, where they activate signaling pathways that lead to cell cycle arrest, repair, and under some circumstances, apoptosis.

C. The spindle assembly checkpoint pathway, which causes initiation of anaphase, utilizes Mad2 and other proteins to regulate APC/CCdc20, which targets securing and mitotic cyclins for ubiquitinylation.

D. The spindle position checkpoint pathway prevents mitotic CDK inactivation when the spindle is mispositioned. In this pathway, localized activators and inhibitors and a sensor that shuttles between them allow cells to sense spindle position.

Which of the following statement is incorrect?

TLS Online TPP Program

#Question id: 2599

#Unit 2. Cellular Organization

The mRNA from the trp operon has a half-life of only about____

TLS Online TPP Program

#Question id: 2601

#Unit 2. Cellular Organization

Condition of basal level transcription (BLT);

TLS Online TPP Program

#Question id: 2604

#Unit 2. Cellular Organization

Best inducer of the lac operon;

TLS Online TPP Program

#Question id: 2605

#Unit 2. Cellular Organization

The precursor of trp is;