plant responses

Cards (56)

  • How do plants respond to their environment?
    Like all living things
  • How do plant responses compare to animal responses?
    They are slower and less obvious
  • What factors do plants respond to?
    Water, light, gravity, and touch
  • Which plant reacts very quickly to stimuli?
    Venus flytrap
  • What are the external factors affecting plant responses?
    1. Temperature
    2. Day Length
    3. Light Intensity
    4. Gravity
    5. CO2 Concentration
    6. Water
  • What happens to enzyme activity in colder temperatures?
    It is low and growth is minimal
  • What occurs if temperatures exceed 40 degrees Celsius?
    Enzymes can become denatured
  • What can happen if winter is unusually warm?
    Plants may start to grow and get frost damage
  • What does an increase in day length signal to plants?
    To prepare for growth and reproduction
  • What does decreasing day length in autumn signal to plants?
    To produce seeds and ripen fruit
  • How does light intensity affect photosynthesis?
    More light increases the rate of photosynthesis
  • What is the growth direction of plant roots and shoots?
    Roots grow downwards, shoots grow upwards
  • Why do roots grow towards gravity?
    To absorb water and minerals
  • How does carbon dioxide concentration affect photosynthesis?
    More CO2 increases the rate of photosynthesis
  • What happens to a plant if it cannot obtain enough water?
    It wilts and closes its stomata
  • How can plants communicate water shortage to neighbors?
    By signaling to close their stomata
  • What are the main internal factors that regulate plant growth?
    • Growth regulators (plant hormones)
    • Auxins
    • Gibberellins
    • Cytokinins
    • Ethylene
    • Abscisic acid
  • What is a tropism?
    A growth change in response to a stimulus
  • What is a positive growth response in plants?
    Growth towards the stimulus
  • What is phototropism?
    Growth in response to light
  • How do shoots respond to light?
    They bend towards the light
  • How do roots respond to light?
    They grow away from the light
  • What is geotropism?
    Growth in response to gravity
  • How do roots respond to gravity?
    They grow towards gravity
  • How do shoots respond to gravity?
    They grow against gravity
  • What is thigmotropism?
    Growth in response to touch
  • How do tendrils of pea plants respond to touch?
    They grow around objects they touch
  • What is hydrotropism?
    Growth in response to water
  • How do roots respond to water?
    They grow towards water
  • How do shoots respond to water?
    They grow away from water
  • What is chemotropism?
    Growth in response to chemicals
  • How does the pollen tube respond during reproduction?
    It grows towards the ovary
  • What is a growth regulator?
    A chemical that controls plant growth
  • What are the two categories of growth regulators?
    1. Growth Promoters – increase growth
    2. Growth Inhibitors – inhibit growth
  • How are plant growth regulators transported?
    Via the vascular system, phloem
  • How do plant growth regulators compare to animal hormones?
    Similar in chemical nature and function
  • What is the most common natural auxin?
    Indole acetic acid (IAA)
  • Where is IAA produced?
    In apical meristems, young leaves, seeds
  • What are the effects of auxins?
    Stem elongation, root and shoot growth
  • How do auxins cause phototropism?
    By diffusing to the shaded side of the shoot