Ecology SOL Unit 3.2 - Oxygen Cycle

What is the most common element in the human body?

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

Answer explanation

Oxygen is the most abundant element in the human body, making up about 65% of body mass. It is essential for cellular respiration and is a key component of water, which is vital for life.

What percentage of the Earth's atmosphere is made up of oxygen?

• 10%

• 21%

• 30%

• 50%

Answer explanation

Oxygen makes up about 21% of the Earth's atmosphere. This is a well-established fact in atmospheric science, distinguishing it from other gases like nitrogen, which comprises around 78%.

Which TWO of the following are the byproducts of cellular respiration?

• Oxygen

• Carbon dioxide

• Water

Answer explanation

During cellular respiration, glucose is broken down, producing carbon dioxide and water as byproducts. Oxygen is consumed in the process, but it is not a byproduct.

Tags

NGSS.HS-LS1-7

Where does pyruvate oxidation occur?

• Cytoplasm

• Mitochondrial matrix

• Chloroplast

• Nucleus

Answer explanation

Pyruvate oxidation occurs in the mitochondrial matrix, where pyruvate is converted into acetyl-CoA before entering the citric acid cycle. This process is crucial for cellular respiration and energy production.

Tags

NGSS.HS-LS2-3

What is the chemical formula for glucose?

• C₆H₁₂O₆

• H₂O

• CO₂

• O₂

Answer explanation

The chemical formula for glucose is C₆H₁₂O₆, which indicates it contains 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. The other options represent water (H₂O), carbon dioxide (CO₂), and oxygen (O₂), which are not glucose.

Tags

NGSS.HS-LS2-5

Which TWO of the following are accurate about the Krebs Cycle?

• Another name for the Krebs Cycle is Citric Acid Cycle.

• It occurs in the cell membrane.

• It occurs in the matrix of the mitochondria

• Another name for the Krebs Cycle is Hydrologic Cycle.

Answer explanation

The Krebs Cycle, also known as the Citric Acid Cycle, occurs in the matrix of the mitochondria, where it plays a crucial role in cellular respiration.

Tags

NGSS.HS-LS2-3

What is a byproduct of photosynthesis?

• Carbon dioxide

• Water

• Oxygen

• ATP

Answer explanation

Oxygen is a byproduct of photosynthesis, which occurs when plants convert carbon dioxide and water into glucose and oxygen using sunlight. The oxygen released is essential for the survival of most living organisms.

Tags

NGSS.MS-LS1-6

Which phase of photosynthesis involves the use of carbon dioxide?

• Sunlight phase

• Calvin Cycle

• Krebs Cycle

• Electron Transfer Chain

Answer explanation

The Calvin Cycle is the phase of photosynthesis that uses carbon dioxide to produce glucose. It occurs in the stroma of chloroplasts and does not require light, unlike the sunlight phase.

Tags

NGSS.HS-LS2-5

What is the main purpose of the Electron Transfer Chain?

• To produce glucose

• To convert compounds into ATP

• To capture sunlight

• To release oxygen

Answer explanation

The main purpose of the Electron Transfer Chain is to convert compounds into ATP, which is the energy currency of the cell, through a series of redox reactions that ultimately lead to ATP synthesis.

Tags

NGSS.HS-LS1-7

Label the diagram with the following terms.

a

b

c

d

Chloroplast

Mitochondria

Carbon dioxide

Oxygen

Tags

NGSS.HS-LS1-7

NGSS.HS-LS1-5