Answer:
1. Generally speaking, onions grow tops in cool weather and form bulbs when the weather warms. Plant onion seeds four to six weeks before the last average frost — or even earlier indoors or in a cold frame. When indoor seedlings are 2 to 3 inches tall, harden them off by exposing them to above-freezing night temperatures
2.Transport between roots and leaves. Long-distance movement of water and nutrients is mainly through the xylem tracheids and vessels and the phloem sieve elements of the vascular system (Figure 4). The xylem tracheids and vessels, which are dead cells, can be envisioned as a series of water-filled tubes.
3.Most flowers have four main parts: sepals, petals, stamens, and carpels. The stamens are the male part whereas the carpels are the female part of the flower. Most flowers are hermaphrodite where they contain both male and female parts. Others may contain one of the two parts and may be male or female.
4.Seeds remain dormant or inactive until conditions are right for germination. All seeds need water, oxygen, and proper temperature in order to germinate. ... Then the seed coat breaks open and a root or radicle emerges first, followed by the shoot or plumule that contains the leaves and stem.
