Plant hormones - roots Flashcards
How does auxin affect growth in a plant’s ROOTS?
Auxin INHIBITS growth in the roots
In this way it has the OPPOSITE effect as in the shoots
What does auxin control in terms of root growth?
The direction of growth
In this way it has the SAME effect as in the shoots
Do roots grow towards or away from gravity?
TOWARDS
Will a shoot growing sideways have more auxin on its upper or lower side?
Its LOWER side
Why will a shoot growing sideways have more auxin on its lower side?
Because of gravity pulling it downwards
Do roots grow towards or away from moisture?
TOWARDS
Which 2 things do roots grow towards?
- Gravity
2. Moisture
If a root has an uneven mount of moisture on wither side of the root, will the root grow towards the side with:
a) more moisture?
or
b) less moisture?
a) MORE moisture
How does having more auxin on the bottom of the root affect its growth?
The EXTRA auxin INHIBITS growth. This means the TOP will elongate FASTER, and the root bends DOWNWARDS
How does having more auxin on the more moist side of the root affect its growth?
The EXTRA auxin INHIBITS growth on that side. This means the root grows TOWARDS the MOISTURE, as the cells on the other side elongate FASTER
How are we able to use plant hormones in agriculture?
By extracting or making artificial versions of them
Why can selective weedkillers used in crop-fields only affect weeds and and not the crops?
They are made of plant growth hormones so only affect the broad-leafed plants (which in crop-fields are most commonly weeds (think grasses and cereals as crops)).
What does using weedkiller on weeds do?
It disrupts their normal growth patterns, which soon kills them (but leaves the crops untouched)
When are plant hormones used in agriculture? (2 things)
- As weedkiller
2. To grow plant cuttings
How can you use plant hormones to grow plant cuttings that won’t grow in just soil?
By adding rooting powder (contains auxin hormone), so they’ll produce roots rapidly and start growing as new plants
