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?

#Question id: 5760

#Unit 8. Inheritance Biology

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

#Question id: 5761

#Unit 8. Inheritance Biology

E. coli cells were spread on an agar plate, producing 1000 colonies.  The colonies are replica plated on two agar plates containing the antibiotic kanamycin and one agar plate without antibiotics.  All of the colonies are able to grow on the agar plate without antibiotic but only 4 colonies are able to grow on each of the agar plates containing kanamycin.  You notice that the four colonies that grew on each of the kanamycin containing plates are in the exact same position.  This demonstrates

#Question id: 5762

#Unit 8. Inheritance Biology

An individual cell homozygous for a mutant allele of the gene for a human enzyme contains no detectable activity for that enzyme. The mutation is best described as

#Question id: 5763

#Unit 8. Inheritance Biology

A mutation that causes a mutant phenotype only under restrictive conditions

#Question id: 5764

#Unit 8. Inheritance Biology

A wild-type chromosome can be represented as ABC * DEFGH, and from this a chromosomal aberration arises that can be represented AFED * CBGH. This is known as (* = centromere)

#Question id: 5765

#Unit 8. Inheritance Biology

How many different trisomics could be formed in a plant with a diploid number of 12?