TLS Online TPP Program

#Question id: 5656


What is the cortical reaction, and why is it important?

#Unit 5. Developmental Biology
  1. The cortical reaction is the entry of Ca2+ ions into the egg, which initiates development.

  2. The cortical reaction is the exocytosis of the cortical granules during egg maturation, which contain the components of the zona pellucida.

  3. The cortical reaction is the depolarization of the plasma membrane after sperm entry, which helps to block polyspermy.

  4. The cortical reaction is the release of the cortical granules after sperm entry, which converts the vitelline membrane into the fertilization membrane which blocks polyspermy.

More Questions
TLS Online TPP Program

#Question id: 4880

#Unit 8. Inheritance Biology

There is following normal gene and their restriction site are given

 Mutant phenotype due to mutation that alters EcoRI site 1 occurs in this piece of DNA. There is following analysis of different band in their family (+ present , - absent) 

Visible band

Male Parents I

Female Parents II

Son  ( affected )

Daughter  ( normal)

2 Kb

+

+

-

+

4 Kb

+

+

-

+

5 Kb

+

+

+

+

6 Kb

-

+

+

+

 Which of the following is mode of inheritance of trait?

TLS Online TPP Program

#Question id: 4879

#Unit 8. Inheritance Biology

A wild plant with genes AABBCC was crossed with a triple recessive mutant aabbcc. The F1 male hybrid (AaBbCc) was then back crossed with the triple mutant and the phenotypes recorded are as follows

AabbCc (50), aaBbcc(50), AaBbCc (100), aabbcc (100), AaBbcc (350), aabbCc (350)

Distance between A to B is ----------M----- map unit with ………N…….configuration, distance between B to C is ----O---- map unit with ------P-------configuration?

TLS Online TPP Program

#Question id: 4719

#Unit 8. Inheritance Biology

When a trait exhibits complete co-dominance rather than complete dominance, a cross between heterozygote results deviation of following;

TLS Online TPP Program

#Question id: 4723

#Unit 8. Inheritance Biology

The most common cause of the pleiotropic effect of gene is due to

TLS Online TPP Program

#Question id: 4724

#Unit 8. Inheritance Biology

Which of the following are true about crossing over ?

TLS Online TPP Program

#Question id: 4726

#Unit 8. Inheritance Biology

Which of the following is incorrect regards genomic imprinting?