You calculate map distances between genes A, B, and C based on all pairwise dihybrid crosses. When you perform the trihybrid cross to verify your results, you discover that, despite analysis of a very large number of progeny, you have only about half as many double crossover progeny as you expect. Which explanation is the most reasonable?

#Question id: 10947

#Unit 7. System Physiology – Animal

What occurs following activation of basophils?

#Question id: 11672

#Unit 7. System Physiology – Animal

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because ________

#Question id: 12085

#Unit 10. Ecological Principles

In bottom sediments of lakes and streams, organic matter is broken down by heterotrophic microorganisms and ammonia is released. Under aerobic conditions, specialized bacteria convert ammonia to nitrate (nitrification). This nitrate, together with nitrate from other sources, diffuses into the deeper sediments, where it may undergo anaerobic conversion to nitrogen gas (denitrification). These sediments typically contain oligochaete worms that live with their heads buried and their tails waving back and forth in the overlying water. Plastic columns were packed with freshly collected  stream  sediments  and  then  covered  with  layers  of  nitrate enriched  water.  A  similar  set  of  columns  was packed with sediment that had been sterilized and then covered with either nitrate-enriched water or distilled water. Oligochaete  worms  were  collected  and  acclimated  to  20°(C)Following  acclimation,  worms  were  rinsed  in  distilled water and then added to three sediment columns. The columns were incubated in the dark at 20°C and monitored every three days for changes in the concentration of nitrate in the overlying water. Nitrate concentrations in each of the experimental treatments were plotted against time, as shown in the graph below.

Which of the following explains why the columns were incubated in the dark?

#Question id: 1056

#Unit 4. Cell Communication and Cell Signaling

During penetration of E. coli by the T4 phage

#Question id: 4882

#Unit 8. Inheritance Biology

In Drosophila melanogaster, cinnabar eye (cn)and vestigial wing (vg) are simple recessive traits.a A male pure line wild type eye ,vestigial wing cross with female pure line cinnabar eye, wild type wing . F1female, heterozygous for both genes, was crossed with a male with cinnabar eyes and vestigial wings. The offspring resulting from this cross are listed in below class

I Wild type

II Cinnabar eye, wild-type wing

III Wild-type eye, vestigial wing

IV Cinnabar eye, vestigial wing

Above class are recombinant progeny