The NtrC protein from E. coli

a. is a σ54 RNA polymerase.  b. stimulates transcription of the glnA gene.

c. is activated by a protein kinase called NtrB.

d. binds both to an enhancer site upstream of the glnA gene and to RNA polymerase.

e. has ATPase activity.

#Question id: 11760

#Unit 9. Diversity of Life Forms

Which of the following produce the dense glassy ooze found in certain areas of the deep-ocean floor?

#Question id: 11761

#Unit 9. Diversity of Life Forms

A snail-like, coiled, porous test (shell) of calcium carbonate is characteristic of which group?

#Question id: 11762

#Unit 9. Diversity of Life Forms

Typically as cells grow, their increase in volume outpaces their increase in surface area, and continued survival requires undergoing asexual reproduction to reestablish a healthy surface area to volume ratio. Thus, which of these is least likely to contribute to the ability of a single-celled foraminiferan to grow to a diameter of several centimeters?

#Question id: 11763

#Unit 9. Diversity of Life Forms

What makes certain red algae appear red?

#Question id: 11764

#Unit 10. Ecological Principles

The mathematical model for geometric growth of a population is identical to the model for exponential growth, except that __________ in the geometric model.

#Question id: 11765

#Unit 10. Ecological Principles

The population density of a particular insect species was determined to be 15,000 adults per hectare in the summer of 1996, 21,000 adults per hectare in the summer of 1997, and 29,400 adults per hectare in the summer of 1998. Based on these population estimates, what is your estimate of λ, the annual rate of geometric growth?