ONE-EIGHTH STAGE 2025
Ghana National College: 65 points
Tema Secondary School: 33 points
Effiduase SHCS: 28 points
Mankranso SHS: 43 points
St Paul's SHS, Denu: 23 points
Adonten SHS: 14 points
St. Thomas Aquinas SHS: 51 points
Tamale SHS: 37 points
O'Reilly SHS: 25 points
ROUND 4 - TRUE OR FALSE
SECOND SET OF BIOLOGY TRUE OR FALSE
1. Climate change is an important factor causing algae blooms
ANSWER: TRUE
EXPLANATION:
Rising temperatures and altered precipitation patterns can create favorable conditions for excessive algae growth.
2. Some algae species are nontoxic but still bloom excessively under favorable conditions
ANSWER: TRUE
EXPLANATION:
Even non-toxic algae can form large blooms, disrupting ecosystems by depleting oxygen or blocking sunlight.
3. Warm temperatures can decrease algae growth and increase water mixing resulting in stagnant conditions that are perfect for algae
ANSWER: FALSE
EXPLANATION:
Warm temperatures typically increase algae growth; stagnant conditions promote blooms, but increased water mixing usually reduces bloom formation.
---
PRACTICE QUESTIONS
1. QUESTION: Run-off of fertilisers into lakes can cause algal blooms.
ANSWER: TRUE
EXPLANATION:
Nitrates and phosphates feed the algae.
2. QUESTION: Eutrophication is the enrichment of water with nutrients.
ANSWER: TRUE
EXPLANATION:
It often leads to algal blooms.
3. QUESTION: Algal blooms increase the oxygen in water at night.
ANSWER: FALSE
EXPLANATION:
At night the algae respire and use up oxygen.
4. QUESTION: When the algae die, bacteria decompose them and use up oxygen.
ANSWER: TRUE
EXPLANATION:
Fish may then die.
5. QUESTION: Some algal blooms release toxins that can harm humans and animals.
ANSWER: TRUE
EXPLANATION:
Some cyanobacteria make toxins.
6. QUESTION: Algal blooms let more light reach plants on the lake bed.
ANSWER: FALSE
EXPLANATION:
They block light from reaching submerged plants.
7. QUESTION: Phosphates in detergents can add to eutrophication.
ANSWER: TRUE
EXPLANATION:
Phosphate is often the limiting nutrient.
8. QUESTION: Algal blooms are more common in fast-flowing, cold streams.
ANSWER: FALSE
EXPLANATION:
They are more common in still, warm water.
9. QUESTION: A red tide is a bloom of algae in the sea.
ANSWER: TRUE
EXPLANATION:
It is caused by some dinoflagellates.