Two varieties of maize averaging 25 and 125 inches in height, respectively, are crossed. The F1 progeny is quite uniform averaging 75 inches in height. Plant height is control by 3 QTL, what is the probability of plant with 25 inch height in F2 generation?

#Question id: 1777

#Unit 4. Cell Communication and Cell Signaling

Which of the following mediates type 1 hypersensitivity reaction?

#Question id: 7702

#Unit 9. Diversity of Life Forms

If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

#Question id: 4958

#Unit 11. Evolution and Behavior

What is true of the fossil record of mammalian origins?

#Question id: 10134

#Unit 6. System Physiology – Plant

Some herbicides such as dichlorophenyldimethylurea (DCMU, also known as diuron) and paraquat, block photosynthetic electron flow from where ?

a.) DCMU blocks electron flow at the quinone acceptors of PSII, by competing for the binding site of plastoquinone that is normally occupied by PQB

b.) Paraquat accepts electrons from the early acceptors of PSI and then reacts with oxygen to form superoxide, O2 – , a species that is very damaging to chloroplast components

c.) DCMU blocks electron flow at the pheophytin acceptors of PSII, by competing for the binding site of pheophytin

d.) Paraquat accepts electrons from the Iron-sulfur system of PSI and then reacts with oxygen to form superoxide, O2 – , a species that is very damaging to chloroplast components

Which of the following combination is true?

#Question id: 2667

#Unit 2. Cellular Organization

A regulatory protein that attracts RNA polymerase to its promoter is an example of what type of regulation?