In a particular species of mammal black hair (B) is dominant to green hair (b) and red eyes (R) are dominant to white eyes (r). If a BbRr individual is mated with a bbrrindividual the expected phenotypic ratio of the offspring is 1 black-red : 1 black-white: 1 green-red : 1 green-white. However, when you mate these individuals you find that the phenotypic ratio of the offspring is 6 black-red :1 black-white : 1 green-red : 6 green-white. What could account for this difference?

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#Question id: 2200

#Unit 2. Cellular Organization

A neurotransmitter that binds to a postsynaptic cell and opens K+ channels:

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#Question id: 29571

#Unit 6. System Physiology – Plant

Histone deacetylase activity in the maize (Zea mays) inhibited by

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#Question id: 2918

#Unit 2. Cellular Organization

Some DNA sequences in our cells have high frequencies of methylated cytosines (hypermethylation); some others have a low frequency of methylated cytosines (hypomethylation). Which of the two methylation states best describes the kind of sequences listed below? 

 I. Satellite DNA in pericentromeric heterochromatin

II. Promoters 

III. Dispersed transposon repeats

IV. CpG islands 

V. Enhancers

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#Question id: 14948

#Unit 6. System Physiology – Plant

Cellulose microfibrils have an ordered structure and are synthesized at the plasma membrane, given characteristics of microfibrils;

a) Each microfibril is composed of an estimated 18 parallel chains of (1,4)-linked β-D-glucose chains tightly bonded to each other to form a crystalline microfibril

b) Microfibrils have hydrophilic surfaces, populated by polar –OH groups extending from the plane of the sugar rings

c) Microfibrils have hydrophobic surfaces, populated by nonpolar C–H groups populating the sides of stacked glucose chains

 d) microfibril important for enzymatic attack by microbial cellulases, which dock onto the hydrophobic surface and remove one glucan chain at a time

Which of the following from given characteristics of microfibrils is incorrect?

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#Question id: 817

#Unit 1. Molecules and their Interaction Relevant to Biology

The aggregation of nonpolar side chains in the interior of a protein is favored by