Red kernel color in wheat results from the presence of at least one dominant allele of each of two independently segregating genes . Kernels on rr bb plants are white, and the genotypes R— bb and rr B— result in brown kernel color. Suppose that plants of a variety that is true breeding for red kernels are crossed with plants true breeding for white kernels produced F1 were allowed to selfing .what are F2 phenotype ratio ?

#Question id: 11373

#Unit 9. Diversity of Life Forms

Which of the following obtain energy by oxidizing inorganic substances; energy that is used, in part, to fix CO2?

#Question id: 11374

#Unit 9. Diversity of Life Forms

Which of the following use light energy to generate ATP, but do not release oxygen?

#Question id: 11392

#Unit 9. Diversity of Life Forms

Modes of obtaining nutrients, used by at least some bacteria, include all of the following except

#Question id: 11393

#Unit 9. Diversity of Life Forms

Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what are two ʺstrategiesʺ that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?

1.  couple them with photosystem II (the photosystem that splits water molecules)

2.  package them in membranes that are impermeable to all gases

3.  be obligate anaerobes

4.  be strict aerobes

5.  package these enzymes in specialized cells or compartments that inhibit oxygen entry

#Question id: 11394

#Unit 9. Diversity of Life Forms

Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods would not generally inhibit bacterial growth?

#Question id: 11395

#Unit 9. Diversity of Life Forms

Mitochondria are thought to be the descendants of certain alpha -proteobacteria. They are, however, no longer able to lead independent lives because most

genes originally present on their chromosome have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?