Assume that mating is random. First, consider an autosomal recessive disease that is usually lethal in childhood, and that has an incidence among newborns of 1/3000.  Perhaps the explanation for the incidence of the disease is heterozygote advantage. How large would this heterozygote advantage have to be (assuming the mutation rate is negligible)? 

TLS Online TPP Program

#Question id: 12674

#Unit 10. Ecological Principles

You  have  a  friend  who  is  wary  of  environmentalists? claims  that  global  warming  could  lead  to  major  biological change on Earth. Which of the following statements can you truthfully make in response to your friend's suspicions?

TLS Online TPP Program

#Question id: 12675

#Unit 10. Ecological Principles

Use the incomplete diagram below, illustrating some of the steps involved in eutrophication to answer the following questions

What would be a likely entry for box A?

TLS Online TPP Program

#Question id: 12676

#Unit 10. Ecological Principles

Use the incomplete diagram below, illustrating some of the steps involved in eutrophication to answer the following questions.

What would be a likely entry for box B?

TLS Online TPP Program

#Question id: 12677

#Unit 10. Ecological Principles

Aquatic ecosystems that are most readily damaged by acid are those that lack an important buffer that dissolves into the runoff after a precipitation event. What is this buffer?

TLS Online TPP Program

#Question id: 12755

#Unit 10. Ecological Principles

Which of the following statements best describes why biologists are currently concerned with global warming and the thawing of permafrost in many areas of the tundra biome?

TLS Online TPP Program

#Question id: 12756

#Unit 10. Ecological Principles

Flycatcher birds that migrate from Africa to Europe feed their nestlings mostly with moth caterpillars. The data presented show the mean dates of egg laying, hatching, and fledging of flycatcher young, and the 1980 and 2000 peak mass of caterpillars.

The most likely cause for the shift in caterpillar peak mass is