Gene s controls the sharpness of spines in a type of cactus. cactuses with the dominant allele, s, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. at the same time, a second gene, n, determines whether cactuses have spines. homozygous recessive nn cactuses have no spines at all.
a cross between a true-breeding sharp-spined cactus and a spineless cactus (ssnn) would produce what types of offspring?

All the offspring will have sharp-spined phenotype.

Explanation:

By crossing a true-breeding sharp-spined cactus with a spineless cactus, we're crossing a NNSS x nnss. So to determine the offspring's type, we should consider the gametes that would be produced.

The true-breeding sharp-spined cactus can only produce gametes NS, while the spineless one would produce only ns gametes.

As a result, all the individuals of the first generation after the crossing will have the genotype NnSs.

That means, all the cactus of the offspring will have sharp-spined phenotype.

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.