Plant Responses, Mechanism of Control, & Plant Nutrition Flashcards
The ability of the plant to reorient the shoot growth towards a direction of light source. ______ is a directional response that allows plants to grow towards or in some cases away from, a source of light.
Phototropism
is the movement of plants in response to sunlight during daytime
Heliotropism
It is a plant’s growth response in which the direction of growth is determined by a stimulus or gradient in water concentration.
Hydrotropism
The movement or change in orientation of a plant’s growth as a reaction to touch.
HAPTOTROPISM
Thigmotropism
On the other hand, when the roots touched a rock, they grew away from it, showing _____ thigmotropism.
negative
The growth of roots and shoots toward or away from the direction of gravity. The response of plants to gravity implies starch-filled plastids, the statoliths, which sediments at the bottom of the gravisensing cells, the statocytes.
Gravitropism/Geotropism
____ are signaling biomolecules released by plants and animals that have a function in the control of physiological processes as well as the upkeep of homeostasis in the body of living beings.
Hormones
Animal hormones can diffuse through the ____ , while plant hormones diffuse through the ____ & ____
Blood (circulatory system), phloem and xylem.
What are the plant hormones
Auxin
Ethylene
Gibberellins
Brassinosteroids
Stimulates stem elongation (low concentration only); promotes the formation of lateral and adventitious roots; regulates development of fruit; enhances apical dominance; functions in phototropism and gravitropism;
Auxin
Promotes ripening of many types of fruit, leaf abscission, and the triple response in seedlings (inhibition of stem elongation, promotion of lateral expansion, and horizontal growth)
Ethylene
Stimulate stem elongation, pollen development, pollen tube growth, fruit growth, and seed development and germination
Gibberellins
Promote cell expansion and cell division in shoots; promote root growth at low concentrations
Brassinosteroids
Plants can absorb water and mineral ions from the soil through the process of ______.
osmosis
Just behind the growing tips of roots are thousands of tiny root hairs. These tiny root hairs increase the surface area of the _______ and are the main area of osmosis. Each root hair is a single, specialized cell. Located on the ______, the long, thin outer projection of the hair cell can penetrate through soil particles to reach the soil water.
root epidermis
