☀️Plants Responce Flashcards
Stimulus
Anything that causes a reaction in an organism
Responce
The activity of a cell or organism as a result of a stimulus
Structures required for Responce
Immune system
Method of movement
Nerve / sense organ system
External factors of plant Responce
Light - energy - photosynthesis Day length Gravity Temperature Reaction
Plants grow faster at
A higher temperature
Temperature effects
The rate of an enzyme
Gravity causes roots to
Grow down into the soil and shoots upwards
Internal factors
Plants produce chemicals called growth regulators
Where are growth regulators produced
In the meristem
Tropism
The change in the growth of a plant in Responce to an external stimulus
Positive tropism
Occurs when the growth is towards a stimulus
Negative tropism
Occurs when the growth is away from the stimulus
Name the 4 types of tropisms
Phototropism
Geotropism
Hydrotropism
Chemotropism
Photo tropism
Change in growth of a plant in Responce to light
Geotropsim
Change in growth of a plant in respond to gravity
Hydrotropism
Change in growth of a plant in Responce to water
Chemotropism
Change in growth of a plant in Responce to chemicals
Growth regulators
Chemicals that change the growth of a plant
Growth promoters
Cause increased plant growth
Name a growth promoter
Auxins
Growth inhibitors
Reduce or stop growth
Name a growth inhibitor
Tehehe
IAA
Indoleacetic acid
IAA
The best known auxin
Effects of auxins are to cause
Tropisms
Fruit formation
Root formation and growth
Functions of auxins
Stimulating growth
Developing fruit
Causing phototropism
Growth inhibitors include
Ethene
Abscisic acid
Cause plants to respond to harmful conditions
Cause stomata to close in dry conditions
Ethene
Gas that ripens fruit
Commercial growth regulators are used to
Ripen fruits
Stimulate root formation (rooting powders)
Plant protection methods
Anatomical / structural (bark)
Chemical (stress proteins)
Name a stress protein
Phytoalexins
When do plants produce stress proteins
When a plant is infected by a micro organism
Name a way in which stress proteins act
Damage microorganisms by attacking their cell wall
