Which statement describes what happens during the germination of a pollen grain
a. a sperm cell fertilizes the egg located to the ovary
b. a zygote develops from the pollen grain
c. the pollen grain produces a tube that grows down towards the ovary
d. the pollen grain matures and develops into a seed

During germination of pollen grains, the pollen grains produce a tube that grows down towards the ovary.

 Germination we can term it as the process by which an organism grows from a seed or a similar structure pollen grains are reproductive structures which are also known as pollen tubes that produce male gametophytes. The first step is germination is an emergence of radicle which helps in supply of water to the growing embryo. During germination of pollen grains, it produces a tube that grows down towards the ovary. The growth of a plant which founds with a seed is called germination and it results in the formation of the grain. The companionship of male and female reproductive cells is where the seed of the vascular plant produces. Developed seeds contain an embryo and, where plant species store of food reserves, and wrapped in a seed coat. Different numbers of seeds lack nuclei which are produced by some plants, and they are called dry seeds and they never germinate. Ripe seeds that do not grow are called dormant seeds, and they are subject to external environmental conditions of metabolic processes and cell growth are prevented. Embryonic tissues resume growth, and seed begins to germinate developing towards seedling when given proper conditions.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.