5.5 Plant responses Flashcards
where is the apical meristem found?
at the top of the shoots
where is the lateral meristem found?
circularly in the stem
where is the intercalary meristem found?
at the nodes of internodes in the stem
what is the name for all cells being unspecialised?
totipotent
what is at the end of the root?
zone of cell division (with meristems)
what is in the middle of a root?
zone of elongation
what is at the top of a root?
zone of differentiation
What are the effects of auxins on plants?
promotes cell elongation
inhibits growth of side shoots
inhibits leaf abscission
what are the effects of gibberellins on plants?
promotes seed germination and growth of stems
what are the effects of ethene on plants?
promotes fruit ripening
what are the effects of abscisic acid (ABA) on plants?
inhibits seed germination and growth
causes stomatal closure when low water availability
what are the effects of cytokinins on plants?
promotes cell division
delay leaf senescence
overcome apical dominance
promotes cell expansion
What are the 5 tropisms?
photo-
geo-
hydro
thigmo-
chemo-
what is the stimulus for each of the tropisms?
photo : light
geo : gravity
hydro : water
thigmo : touch
chemo : chemicals
what is the advantage to each of the tropisms?
photo : maximum light absorption
geo : anchors plants, reaches mineral ions
hydro : more turgid and photosynthesis
thigmo : more stable , doesn’t support itself
chemo : reproduce easily
what happens at positive chemotropism?
pollen lands on stigma
grows a pollen tube to reach ovary
fertilizes ovum in ovary
what is the process of seed germination using gibberellins?
- water enters and embryo releases gibberellins
- GB moves to aleurone layer in endosperm region
- starch —-> maltose —–> glucose using amylase
- glucose used during respiration
- more GB = more amylase
