In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following, if found in cells or organisms as they age, would provide evidence that this is related to cell signalling?

#Question id: 12222

#Unit 7. System Physiology – Animal

#Question id: 1380

#Unit 4. Cell Communication and Cell Signaling

Which of the following apply to the synthesis of plant cell walls? Please select all that apply.

a) Cellulose microfibrils are formed by cellulose synthase complexes called rosettes

b) Cellulose is synthesized using cytoplasmic ATP-glucose and deposited as microfibrils directly on the outer surface of the plasma membrane.

c) Matrix polysaccharides of plant cell walls are synthesized in the Golgi apparatus and exported to the cell wall by endocytosis.

d) The direction of cellulose microfibril growth is determined by the orientation of arrays of microtubules lying just below the plasma membrane.

#Question id: 657

#Unit 1. Molecules and their Interaction Relevant to Biology

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.

#Question id: 12527

#Unit 6. System Physiology – Plant

#Question id: 594

#Unit 1. Molecules and their Interaction Relevant to Biology

The catalytic proficiency of an enzyme is the ________.