36. Plants have only three tissue types: 1) Dermal; 2) Ground; and 3) Vascular. Dermal tissue covers the outer surface of herbaceous plants. Dermal tissue is composed of epidermal cells, closely packed cells that secrete a waxy cuticle that aids in the prevention of water loss
37. A root is the part of a plant that attaches it to the ground or to a support, typically underground, conveying water and nourishment to the rest of the plant via numerous branches and fibers.
38. A stem is the main body or stalk of a plant or shrub, typically rising above ground but occasionally subterranean.
39. A leaf is a flattened structure of a higher plant, typically green and bladelike, that is attached to a stem directly or via a stalk. Leaves are the main organs of photosynthesis and transpiration.
40. Taking in oxygen is very important because it allows your cells to do things, like make energy from the food you eat. Plants 'breathe' too, but they do it through tiny openings in leaves called stomata (singular: stoma). Stomata open and close to allow the intake of carbon dioxide and the release of oxygen.
41. Plants have two different types of transport tissue. Xylem transports water and solutes from the roots to the leaves, phloem transports food from the leaves to the rest of the plant. Transpiration is the process by which water evaporates from the leaves, which results in more water being drawn up from the roots.
42. Forms of tropism include phototropism (response to light), geotropism (response to gravity), chemotropism (response to particular substances), hydrotropism (response to water), thigmotropism (response to mechanical stimulation), traumatotropism (response to wound lesion), and galvanotropism, or electrotropism
43. Auxins, cytokinins, gibberellins, ethylene and abscisic acid. Auxins are hormones that stimulate growth and are produced in immature parts of plants. They were the first group of hormones studied in plants.
