Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 55052
TLS Online TPP Program

#Question id: 12835

Following statements are regarding to the surveillance mechanism. Which of the following statement is incorrect?

#Unit 2. Cellular Organization
  1. DNA damage leads to the activation of p21, a transcription factor that induces the expression of the gene encoding the CDK inhibitor p53.
  2. When the DNA damage occurs during S phase or in G2, Cdc25C inhibition by Chk1/2 results in the inhibition of mitotic CDKs and hence arrest in G2.
  3. Cells sense DNA replication stress that results in stalling or slowing of replication forks. Such stress triggers activation of the ATR-Chk1 checkpoint pathway and results in downregulation of S phase CDK activity and prevents the firing of late-replicating origins.
  4. ATM halts cell cycle progression by Chk2-mediated inhibition of Cdc25, thus preventing activation of CDKs. This inhibition can occur in G1 or G2.
More Questions
TLS Online TPP Program

#Question id: 12285

#Unit 10. Ecological Principles

The principle of competitive exclusion states that
TLS Online TPP Program

#Question id: 12286

#Unit 10. Ecological Principles

Keystone predators can maintain species diversity in a community if they
TLS Online TPP Program

#Question id: 12287

#Unit 10. Ecological Principles

Food chains are sometimes short because
TLS Online TPP Program

#Question id: 3296

#Unit 10. Ecological Principles

Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of
TLS Online TPP Program

#Question id: 12349

#Unit 10. Ecological Principles

Males in a population differ in the time they spend displaying to females. A researcher hypothesizes that predators are responsible for these differences. Males display for longer durations when there are no predators in the vicinity and for shorter durations when there is a predator nearby. Which of the following study designs is the most appropriate test of this hypothesis?
TLS Online TPP Program

#Question id: 12347

#Unit 10. Ecological Principles

A team of conservation biologists, surveying a population of frogs on an island, captured and marked 312 individuals in the first sample. In a second sampling, 3 days later, the team caught 140 individuals of which 26 were previously marked. The total number of frogs on the island is estimated to be . (Use decimal notation, not fractions or percentage)