You are interested in a new type of autosomal dominant mutation that gives purple eyes in Drosophila. You have a true-breeding purple-eyed line carrying a mutation that you call pr-1. You have isolated a second purple-eyed mutation that you call pr-2, which you have established in a true-breeding line that also carries a recessive marker st, which gives stubby legs. You cross a fly from the pr-1 line to a fly from the st, pr-2 line producing F1 females which you then cross to males from a true breeding st line (normal eyes). From this cross, 1000 progeny flies can be categorized into four different phenotypic classes:

                             

Normally, 3-factor crosses give eight different phenotypic classes, why does this particular cross give only four?

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#Question id: 10986

#Unit 7. System Physiology – Animal

Which of the following conditions at the A-V node will cause a decrease in heart rate?

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#Question id: 31115

#Unit 2. Cellular Organization

Troponin C is closely related to the ubiquitous Ca2+-binding protein, called: 

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#Question id: 4530

#Unit 3. Fundamental Processes

A protein complex engaged in the pairing of homologous chromosomes during cell division has also been implicated in stabilizing certain enhancer–promoter loops.

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#Question id: 31170

#Unit 7. System Physiology – Animal

Depolarization in myelinated axons travels from one node of Ranvier to the next, called as:

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#Question id: 12906

#Unit 13. Methods in Biology

An alternative method labeling strategy used in karyotyping and gene localisation is _______