Tay-sachs disease is due to the absence of an enzyme that
a. digests polysaccharides.
b. involves damage to liver cells.
c. prevents the breakdown of glycogen.
d. causes an accumulation of lipids in brain cells.

D. Causes an accumulation of lipids in brain cells

Explanation:

Tay-Sachs disease is caused by a genetic mutation in the HEXA gene. It is an autosomal recessive disease that causes the mutation on an enzyme, which metabolizes GM2 Ganglioside in nerve cells, this leads to a build-up of the molecule in brain cells. At the moment there is no cure for the disease, only support treatment is available.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.