TLS Online TPP Program

#Question id: 5672


Following statements are regarding to recognition of sperm by mammalian zona pellucida.

A. Sperm that have undergone the acrosome reaction bind directly to zona protein ZP2 and begin making a channel toward the oocyte.

B. Sperm with an intact acrosome bind to ZP2; they undergo the acrosome reaction on the zona pellucida and then transfer their binding to ZP3.

C. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest portions of ZP2 and ZP3, making them nonfunctional and prevent polyspermy.

D. When a sperm reaches the oocyte and fuses with it, the cortical granules release proteins that digest ZP3 only, not ZP2 because ZP2 involve in the process of slow block to polyspermy.

Which of the above statements are correct?

#Unit 5. Developmental Biology
  1. A and B

  2. A, B and C

  3. A and C

  4. C only

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TLS Online TPP Program

#Question id: 5322

#Unit 11. Evolution and Behavior

A current view of how the human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter ________.

TLS Online TPP Program

#Question id: 5323

#Unit 8. Inheritance Biology

An X-linked recessive gene produces red-green color blindness in humans. A woman with normal color vision whose father was color-blind marries a color-blind man. What is the probability that their son will be color-blind?

TLS Online TPP Program

#Question id: 5324

#Unit 8. Inheritance Biology

In eusocial insects, males develop from unfertilized eggs while females develop from fertilized eggs. The ultimate consequence of this difference is that

TLS Online TPP Program

#Question id: 5325

#Unit 8. Inheritance Biology

Cystic fibrosis is caused by a recessive lethal gene and can be detected by an excess concentration of chloride in sweat. A normal man whose sister has cystic fibrosis, his normal wife whose brother has cystic fibrosis. What is chance of cystic fibrosis in their child?

TLS Online TPP Program

#Question id: 5326

#Unit 8. Inheritance Biology

The recessive allele located on heterozygous locus present on X-chromosome in female is conclude as

TLS Online TPP Program

#Question id: 5327

#Unit 8. Inheritance Biology

In the human pedigree shown here, the daughter indicated by the black circle (II-1) has a form of deafness determined by a recessive allele. What is the probability that the phenotypically normal son (II 3) is heterozygous for the gene?