The following structural changes occur as conducting tubes
become smaller;
- support structures change. The trachea has more hyaline cartilage
than the bronchioles
- epithelium type changes with bronchioles having ciliated
columnar cells with the trachea having tall columnar pseudostratified
- amount of smooth muscle increases as you go lower the respiratory tract
If I have a batch of pea plants with purple flowers that I grew by crossing plants that had purple flowers (PP) with plants that had white flowers (pp), purple flowers (dominant) will be expressed in this batch of pea plants.
c.Stomata are generally open during the day to remove excess water from the planet and closed at night to keep oxygen from escaping.