The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

 Which pair of scientists below would probably have agreed with the process that is depicted by this tree?

#Question id: 608

#Unit 1. Molecules and their Interaction Relevant to Biology

The ʺTʺ state refers to the ________.

#Question id: 609

#Unit 1. Molecules and their Interaction Relevant to Biology

The ________ theory explains cooperative binding by suggesting all subunits of a given protein have the same conformation, either all R or all T.

#Question id: 610

#Unit 1. Molecules and their Interaction Relevant to Biology

Protein A has four identical subunits, each of which binds one molecule of ligand Y. The binding of one molecule of Y to one of the subunits induces a conformational change in neighboring subunits that enhances the binding of additional units of Y. This is an example of________.

#Question id: 611

#Unit 1. Molecules and their Interaction Relevant to Biology

Which statement is false about the sequential theory of enzyme catalysis?

#Question id: 612

#Unit 1. Molecules and their Interaction Relevant to Biology

 The quaternary structure of hemoglobin changes from the T state to the R state ________.

#Question id: 613

#Unit 1. Molecules and their Interaction Relevant to Biology

Ethanol (CH3CH2OH) is the alcohol found in beverages. It is oxidized in the body to acetaldehyde by the enzyme alcohol dehydrogenase. Methanol (CH3OH), also known as wood alcohol, is converted to formaldehyde by the same enzyme. Acetaldehyde is toxic, but formaldehyde is far more toxic to humans, which is why the ingestion of relatively small amounts of methanol can cause blindness or death. One treatment for mild methanol poisoning is the administration of ethanol. Why might a doctor choose this treatment?