<span>As the pollen tube penetrates the ovule, it releases two sperm cells. As in gymnosperms, the ovule becomes a seed, encasing the embryo and endosperm in a seed coat. But unlike gymnosperms, in angiosperms the ovary containing the ovules develops into a fruit after fertilization.</span>
Exactly how many chromosomes we are talking about depends on the species. A mosquito has 6 chromosomes, a pea plant has 14, a sunflower 34, a human being 46, and a dog 78. Closely related species tend to have a similar number of chromosomes.
Answer:
The average adult, when resting, inhales and exhales about 7 or 8 liters of air per minute. That totals about 11,000 liters of air per day. Inhaled air is about 20-percent oxygen. Exhaled air is about 15-percent oxygen.
Explanation:
