TLS Online TPP Program

#Question id: 5760


The fluctuation test of Luria and Delbruck (studying resistance to bacteriophge T1 infection) established that

#Unit 8. Inheritance Biology
  1. T1 phage was a mutagen.

  2. Mutations could arise prior to the time they were selected

  3. The mutation rate varies greatly from experiment to experiment.

  4. In E. coli the number of mutants per clone was relatively constant.

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TLS Online TPP Program

#Question id: 11457

#Unit 7. System Physiology – Animal

Dizziness is a perceived sensation that can occur when ________.

TLS Online TPP Program

#Question id: 12659

#Unit 7. System Physiology – Animal

 Which of the following would tend to decrease plasma potassium concentration by causing a shift of potassium from the extracellular fluid into the cells?

TLS Online TPP Program

#Question id: 5453

#Unit 8. Inheritance Biology

On which of the following factors, the amount of melanin produced depends?

TLS Online TPP Program

#Question id: 10665

#Unit 10. Ecological Principles

Complete the following hypothetical life table of a species. 


Initial population size is 1000. What will be population size in next generation?


TLS Online TPP Program

#Question id: 7224

#Unit 5. Developmental Biology

Following statements are given regarding to the migration through primitive streak in chick.

A. Cells migrate to the primitive streak, and as they enter the embryo, the deep-moving cells give rise to the endodermal organs of the embryo, as well as to most of the extraembryonic membranes.

B. The migration of mesodermal cells through the anterior primitive streak and their condensation to form the chordamesoderm also appear to be controlled by FGF and Wnt signalling.

C. Wnt is expressed in the primitive streak and repels migrating cells away from the streak. 

D. Once cells migrate away from the streak, further movement of the mesodermal precursors appears to be regulated by FGF8 proteins.

Which of the following statement is incorrect?