TLS Online TPP Program

#Question id: 5671


Match the following mechanism of polyspermy (Column I) with events (Column II).

 Column I

 Column II

A. Fast block to polyspermy

i. chemicals from the fusing sperm cytoplasm alter the sodium ion (Na+) channels on the membrane

B. Slow block to polyspermy

ii. enzyme cortical granule serine

protease, cleaves the protein posts that connect the vitelline envelope

iii the concentration of free Ca2+ in the egg cytoplasm increases

iv. an electric change in the egg cell membrane

v. the concentration of free Na+ in the egg cytoplasm increases

Which of the following is correct?

#Unit 5. Developmental Biology
  1. A. iv, v B. i, ii, iii

  2. A. i, ii, v B. iii, iv

  3. A. i, iv, v B. ii, iii

  4. A. i, ii, iii B. iv, v

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TLS Online TPP Program

#Question id: 10329

#Unit 9. Diversity of Life Forms

If birds are excluded from the class Reptilia, the term that consequently describes the class Reptilia is

TLS Online TPP Program

#Question id: 10330

#Unit 9. Diversity of Life Forms

If the eukaryotic condition arose, independently, several different times during evolutionary history, and if ancestors of these different lineages are extant and are classified in the domain Eukarya, then the domain Eukarya would be

TLS Online TPP Program

#Question id: 10331

#Unit 9. Diversity of Life Forms

When using a cladistic approach to systematics, which of the following is considered most important for classification?

TLS Online TPP Program

#Question id: 10332

#Unit 9. Diversity of Life Forms

The four-chambered hearts of birds and the four-chambered hearts of mammals evolved independently of each other. If one were unaware of this independence, then one might logically conclude that

TLS Online TPP Program

#Question id: 10333

#Unit 6. System Physiology – Plant

Four elements, oxygen, carbon, and hydrogen and nitrogen are the major components of most organic compounds, which of the following elements are more abundant in plants ?

TLS Online TPP Program

#Question id: 10334

#Unit 6. System Physiology – Plant

N2 combines with hydrogen to form ammonia under elevated temperature (about 200°C) and high pressure (about 200 atmospheres) and in the presence of a metal catalyst (usually iron). The extreme conditions are required to overcome the high activation energy of the reaction. This nitrogen fixation reaction, called