M3 IQ3B Solar Radiation and Life

What is the primary process by which light energy from the Sun is converted into chemical energy in living organisms?

• Respiration

• Chemosynthesis

• Photosynthesis

• Fermentation

Answer explanation

Photosynthesis is the primary process by which light energy from the Sun is converted into chemical energy in living organisms.

How much of the Sun’s radiant energy is ultimately trapped in the biosphere by photosynthesis?

• 10-20%

• 1-2%

• 30-40%

• 50-60%

Answer explanation

Only 1-2% of the Sun's radiant energy is ultimately trapped in the biosphere by photosynthesis, making it the correct choice.

What is the chemical equation for photosynthesis?

• 6O2 + C6H12O6 → 6CO2 + 6H2O

• 6CO2 + 6H2O → C6H12O6 + 6O2

• H2O + O2 → H2O2

• CO2 + H2O → CO + H2

Answer explanation

The correct chemical equation for photosynthesis is 6CO2 + 6H2O → C6H12O6 + 6O2.

Where in the ocean are photosynthetic organisms mostly found?

• At the ocean floor

• In deep trenches

• In shallow areas and near the surface

• In hydrothermal vents

Answer explanation

Photosynthetic organisms are mostly found in shallow areas and near the surface of the ocean where sunlight can penetrate for photosynthesis.

Which pigments are primarily involved in absorbing light for photosynthesis?

• Chlorophyll a and chlorophyll b

• Melanin and hemoglobin

• Xanthophyll and anthocyanin

• Carotene and phycocyanin

Answer explanation

Chlorophyll a and chlorophyll b are primarily involved in absorbing light for photosynthesis.

What layer formed due to the oxygen produced by photosynthetic organisms, enabling life to spread on land?

• Stratosphere

• Hydrosphere

• Ozone layer

• Troposphere

Answer explanation

The ozone layer formed due to the oxygen produced by photosynthetic organisms, enabling life to spread on land.

What is the term for organisms that can make their own nutrients through processes like photosynthesis?

• Heterotrophs

• Decomposers

• Autotrophs

• Scavengers

Answer explanation

Autotrophs are organisms that can make their own nutrients through processes like photosynthesis, distinguishing them from heterotrophs, decomposers, and scavengers.

Which organisms are capable of performing photosynthesis?

• All bacteria

• Green plants, some protists, and some bacteria

• Only animals

• Only fungi

Answer explanation

Green plants, some protists, and some bacteria are capable of performing photosynthesis.

What is the main by-product of the light reactions in photosynthesis?

• Glucose

• Water

• Oxygen

• Carbon dioxide

Answer explanation

The main by-product of the light reactions in photosynthesis is Oxygen.

Which factor does NOT significantly affect the amount of sunlight reaching the Earth's surface?

• Latitude

• Cloud cover

• Earth’s albedo

• Soil type

Answer explanation

Soil type does NOT significantly affect the amount of sunlight reaching the Earth's surface, unlike latitude, cloud cover, and Earth’s albedo.