There is a growing body of evidence that acetylation of histone N-termini in specific chromosomal regions contributes to gene control by regulating the binding of histones to DNA and regulation of the folding state of chromatin. The extent of histone acetylation is correlated with the relative resistance of chromatin DNA to digestion by nucleases. Which combination of histone acetylation state and DNAse 1 resistance is characteristic of actively transcribed regions of chromatin?

#Question id: 11710

#Unit 9. Evolution & Diversity of Life Forms

Why is the filamentous morphology of the water molds considered a case of convergent evolution with the hyphae (threads) of fungi?

#Question id: 11711

#Unit 9. Evolution & Diversity of Life Forms

The Irish potato famine was caused by an organism that belongs to which group?

#Question id: 11712

#Unit 9. Evolution & Diversity of Life Forms

The following are all characteristic of the water molds (oomycetes) except

#Question id: 11713

#Unit 9. Evolution & Diversity of Life Forms

Theoretically, which two of the following present the richest potential sources of silica?

1.  marine sediments consisting of foram tests

2.  marine sediments consisting of diatom cases (valves)

3.  marine sediments consisting of radiolarian shells

4.  marine sediments consisting of dinoflagellate plates

#Question id: 11714

#Unit 10. Ecological Principles

In recognizing patchiness in the natural world, ecologists have developed three different models of populations. Which of these recognize(s) that there are differences in the quality of habitat patches without considering effects of differences in habitat quality within the habitat matrix?

#Question id: 11715

#Unit 10. Ecological Principles

The lifetime dispersal area of a particular species of drosophila is 0.2 km2. What else would we need to know to determine the neighbourhood size for this species?