NMAT Biology | Botany

Thigmotropism

Plant moves or grows in response to touch or contact stimuli

Thermotropism

Plant moves in response to change in temperature

Heliotropism

Seasonal motion of plant parts in response to the direction of the sun; reversible

Geotropism

Plant movement in response to gravity

Phototropism

Growth of organisms in response to light; irreversible

Equation for photosynthesis

CO2 + H2O + Light → Glucose + O2

Why don’t plants want glucose floating around?

Glucose is soluble in water and can affect the cell’s water balance

If you’re looking for photosynthesis in plants, what substance do you place?

Iodine

• it becomes blue or black when photosynthesis is present

• reacts with glucose

Lanolin Paste

Waxy substance that is taken from sheep’s wool; used to hold and apply plant hormones (auxin) to a specific part of a plan

It’s almost like an ointment that delivers hormones

Auxin

Hormone that controls plan growth & cell elongation; usually on plant tips but if it’s cut off, another option is to mix auxin and lanolin paste

Short-day plants

Plant that care about long nights; flower when days are short

ex: chrysanthemums, poinsettias, rice, soybeans; winter or fall plants

Photoperiodism

Plant’s response to daylight and darkness; it’s a plant’s calendar

Long-day plants

Plants that flower on long days and short nights

ex: Wheat, Spinach, Radish

Cytokinin

Plant growth substance that promotes cell division in plant roots and shoot

• Part of self-growth and differentiation

Gibberellin

Plant hormones that regulate growth and development processes like elongation, germination, dormancy, flower sex expression, enzyme induction, etc.

Ethylene

Hormone used to ripen fruits