An investigator incubates an unprocessed RNA molecule containing an intron in an extract absent of any protein. Correct splicing of the RNA is observed, but only when guanosine is present. What can the investigator conclude about the RNA molecule?

a. It contains a ribozyme. 

b. Self-splicing has occurred.

c. It contains a group II intron.

d. It contains a group I intron.

#Question id: 5011

#Unit 11. Evolution and Behavior

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of

#Question id: 711

#Unit 1. Molecules and their Interaction Relevant to Biology

The shortest alpha helix segment in a protein that will span a membrane bilayer has about.

#Question id: 5291

#Unit 8. Inheritance Biology

A number of nutritional mutant strains were isolated from wild-type Neurospora that responded to the addition of certain supplements in the culture medium by growth ( + ) or lack of growth ( -). Given the following responses for single gene mutations, diagram a metabolic pathway that could exist in the wild-type strain that is most consistent with the data. Indicate where the pathway is blocked in each mutant strain.

#Question id: 11170

#Unit 10. Ecological Principles

Which of the following examples is not a behavioural defense against predators?

#Question id: 15784

#Unit 5. Developmental Biology