ONE-EIGHTH STAGE 2025
Prempeh College: 62 points
Suhum SHTS: 37 points
Benkum SHS: 13 points
Mfantsipim School: 53 points
Anglican SHS, Kumasi: 37 points
Sogakope SHS: 24 points
Adisadel College: 82 points
St. Hubert Seminary SHS: 24 points
Serwaa Nyarko Girls' SHS: 24 points
ROUND 5 - RIDDLE
RIDDLE
I am a phytohormone synthesized in nearly all plant tissues.
I am also produced by some plant pathogenic fungi.
I am traditionally recognized for my role in plant stress responses.
Who am I?
ANSWER: Abscisic acid (ABA)
EXPLANATION:
Abscisic acid is a plant hormone involved in stress responses, such as drought tolerance, stomatal closure, and seed dormancy.
It is synthesized in leaves, roots, and seeds, and some fungi can also produce it to influence host plants
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PRACTICE QUESTIONS
1. RIDDLE:
I am a plant hormone.
I was first found in a fungus that causes "foolish seedling" disease of rice.
I make stems grow tall.
I break seed dormancy.
I trigger amylase production in germinating barley during malting.
I oppose abscisic acid in seed germination.
Who am I?
ANSWER: GIBBERELLIN
EXPLANATION:
Gibberellins promote stem elongation and germination; abscisic acid inhibits germination.
2. RIDDLE:
I am a plant hormone.
I am made mainly in shoot tips.
I move away from the lit side of a shoot.
I cause cells to elongate.
I keep side buds dormant, giving apical dominance.
My main natural form is indole-3-acetic acid (IAA).
Who am I?
ANSWER: AUXIN
EXPLANATION:
Auxin causes cell elongation and controls phototropism and apical dominance.
3. RIDDLE:
I am a plant hormone.
I am made mainly in roots.
I promote cell division.
I delay the ageing of leaves.
In tissue culture, my balance with auxin decides whether shoots or roots form.
Zeatin, from maize, is an example of me.
Who am I?
ANSWER: CYTOKININ
EXPLANATION:
Cytokinins promote cell division and delay senescence.
4. RIDDLE:
I am a plant hormone.
I am a gas.
I ripen fruit.
One overripe fruit releases me and speeds up the ripening of others nearby.
I promote the falling of leaves and fruits.
My formula is $\text{C}_2\text{H}_4$.
Who am I?
ANSWER: ETHYLENE (ETHENE)
EXPLANATION:
Ethylene is the gaseous ripening hormone.
5. RIDDLE:
I am a plant hormone.
I am made from a fatty acid.
I signal damage by chewing insects.
I switch on defence proteins that slow insect digestion.
My methyl ester is a scent in some flowers.
My name comes from the jasmine plant.
Who am I?
ANSWER: JASMONIC ACID
EXPLANATION:
Jasmonic acid signals defence against insect attack.
6. RIDDLE:
I am a plant hormone.
I am a phenolic compound.
I signal defence against disease-causing microbes.
I bring about systemic acquired resistance.
I was first found in willow bark.
Aspirin is made from me.
Who am I?
ANSWER: SALICYLIC ACID
EXPLANATION:
Salicylic acid triggers systemic acquired resistance to pathogens.
7. RIDDLE:
We are plant hormones.
We are steroids.
We were first isolated from the pollen of rape, Brassica napus.
We promote cell expansion and division.
We help plants tolerate stress.
We resemble the steroid hormones of animals.
Who am I?
ANSWER: BRASSINOSTEROIDS
EXPLANATION:
Brassinosteroids are plant steroid hormones that promote growth.
8. RIDDLE:
I am a process in plants.
During me, a plant sheds organs such as leaves, flowers and fruits.
I happen at a separation layer at the base of the organ.
Ethylene promotes me.
Auxin from a healthy leaf delays me.
Abscisic acid got its name because it was first thought to cause me.
Who am I?
ANSWER: ABSCISSION
EXPLANATION:
Abscission is the shedding of leaves, flowers or fruits.
9. RIDDLE:
We are pores.
We are found in the epidermis.
Most of us are on the underside of leaves.
Each of us is bordered by two guard cells.
We usually open in light.
Abscisic acid closes us in drought to reduce water loss.
Who am I?
ANSWER: STOMATA
EXPLANATION:
Abscisic acid makes guard cells lose potassium ions and water, closing the stomata.