Fever is an abnormal elevation of body temperature. Following statements are regarding to the cellular mechanism of fever.

A. Pyrogens produce fever by increasing the hypothalamic set-point temperature.

B. the mechanism of pyrogen action is increased production of interleukin-1 (IL-1) in phagocytic cells.

C. IL-1 then acts on the anterior hypothalamus to increase local production of prostaglandins, which increase the set-point temperature.

D. IL-1 then acts on the posterior hypothalamus to increase local production of prostaglandins, which increase the set-point temperature.

E. IL-1 then acts on the posterior hypothalamus to increase local production of prostaglandins, which decrease the set-point temperature.

Which of the following combination is correct?

#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?

#Question id: 11766

#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.

What would you expect the insect population to be in the summer of 2000, assuming no change in λ?

#Question id: 11767

#Unit 10. Ecological Principles

If a population has a stable age distribution, which of the following statements is true?