The blood-brain barrier is made up of

a. ependymal cells and venous blood vessels.
b. astrocyte perivascular feet and capillary endothelial cells.
c. microglial extensions and capillary endothelial cells.
d. astrocyte extensions and dural sinuses.
e. astrocyte perivascular feet and the falx cerebri.

Where is the energy in a sucrose molecule stored? o a. inside the hydrogen atoms o b. inside the carbon atoms o c. in the bonds between the atoms o d. inside the protons

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human x chromosome. the patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. they rarely live past their twenties. how likely is it for a woman to have this condition? a) women can never have this condition.b) one-fourth of the daughters of an affected man would have this condition.c) one-half of the daughters of an affected father and a carrier mother could have this condition.d) only if a woman is xxx could she have this condition.

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.