Your friends Ben and Jane are contemplating having children and seek your genetic counsel. Ben and Jane are unrelated, but both have younger brothers with the same, extremely rare genetic trait. (In fact, Ben and Jane met at a support group meeting for children and families of children with this rare disorder.) Ben’s parents and Jane’s parents are all unaffected.          

Assume that the trait is autosomal dominant with 80% penetrance in heterozygotes and 100% penetrance in homozygotes. If not affected, what is the probability that the child is a carrier?

#Question id: 14477

#Unit 13. Methods in Biology

#Question id: 18940

#Unit 13. Methods in Biology

#Question id: 8680

#Unit 9. Diversity of Life Forms

Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics. In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species

By examining the phylogenetic tree diagrammed in the figure above, what conclusion can you draw about the species G. microti?

#Question id: 10176

#Unit 6. System Physiology – Plant

Leaves acclimate to sun and shade environments, Sun and shade leaves have contrasting biochemical and morphological characteristics such as

a.) Shade leaves increase light capture by having more total chlorophyll per reaction center, a higher ratio of chlorophyll b to chlorophyll a, and usually thinner laminae than sun leaves

b.) Sun leaves decrease CO2 assimilation by having less rubisco and can dissipate excess light energy and Morphologically they have thinner leaves and a larger palisade layer than shade leaves

c.) Shade leaves decrease light capture by having low total chlorophyll per reaction center, a higher ratio of chlorophyll b to chlorophyll a, and usually thicker laminae than sun leaves

d.) Sun leaves increase CO2 assimilation by having more rubisco and can dissipate excess light energy and Morphologically they have thicker leaves and a larger palisade layer than shade leaves

Which of the following combination from the above statements are TRUE?

#Question id: 11840

#Unit 1. Molecules and their Interaction Relevant to Biology

During an ethylene signalling pathway, what will have done  inside cytosol and nucleus . Given below some prediction about presence and absence of ethylene in column B match with column A