The graph shows the effect of varying auxin concentration on the root and shoot of a plant - Leaving Cert Biology - Question (b) - 2005
Question (b)
The graph shows the effect of varying auxin concentration on the root and shoot of a plant.
(i) What is an auxin?
(ii) At what approximate auxin concentration does... show full transcript
Worked Solution & Example Answer:The graph shows the effect of varying auxin concentration on the root and shoot of a plant - Leaving Cert Biology - Question (b) - 2005
Step 1
What is an auxin?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
An auxin is a type of growth regulator found in plants that is responsible for regulating various aspects of growth and development, such as cell elongation, root formation, and various other physiological processes.
Step 2
At what approximate auxin concentration does the root receive maximum stimulation?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The root receives maximum stimulation at an approximate auxin concentration of 10−3 to 10−2 parts per million.
Step 3
At what approximate auxin concentration does the shoot receive maximum stimulation?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The shoot receives maximum stimulation at an approximate auxin concentration ranging from 1 to 10 parts per million.
Step 4
What is the effect on the root of an auxin concentration of $10^{3}$ parts per million?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
At an auxin concentration of 103 parts per million, the root experiences significant inhibition, which leads to reduced growth or negative effects on root development.
Step 5
Give two examples of uses of synthetic (man-made) auxins.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Rooting powder used in plant propagation.
Tissue culturing in horticulture for plant breeding.
Step 6
Describe three methods used by plants to protect themselves from adverse external environments.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Thorns or modified leaves (e.g., pine needles) that deter herbivory.
The presence of deep roots that access water sources during drought.
Production of antimicrobial chemicals as a defense mechanism.
Join the Leaving Cert students using SimpleStudy...
