1.
What is photosynthesis?
Correct Answer
B. Conversion of light to chemical energy
Explanation
Photosynthesis is the process through which plants, algae, and certain bacteria convert light energy into chemical energy. Specifically, light energy is captured by chlorophyll and used to convert carbon dioxide and water into glucose and oxygen. This transformation is critical as it forms the basis of the energy supply for nearly all life forms on Earth by providing organic molecules and atmospheric oxygen.
2.
Which organism performs photosynthesis?
Correct Answer
C. Plants
Explanation
Plants are the primary organisms that perform photosynthesis. This biological process enables them to produce glucose and oxygen from carbon dioxide and water, using sunlight as the energy source. Through photosynthesis, plants convert inorganic substances into organic molecules, thus serving as the foundational producers in ecosystems and supporting life by replenishing atmospheric oxygen.
3.
What is the primary pigment in plants that absorbs light?
Correct Answer
A. ChloropHyll
Explanation
Chlorophyll is the primary pigment in plants responsible for absorbing light necessary for photosynthesis. It captures specific wavelengths of light most effectively, particularly in the blue and red spectrum, while reflecting green, which is why plants appear green. Chlorophyll’s ability to absorb light energy and convert it into a form usable for chemical reactions in the chloroplast makes it essential for the photosynthetic process.
4.
Where does photosynthesis occur in plant cells?
Correct Answer
C. Chloroplasts
Explanation
Photosynthesis occurs in the chloroplasts of plant cells. These organelles contain chlorophyll and are optimized for converting light energy into chemical energy. Chloroplasts have a unique structure with thylakoid membranes where the light-dependent reactions of photosynthesis capture sunlight, and the stroma where the Calvin cycle synthesizes glucose from carbon dioxide, demonstrating a specialized adaptation for photosynthesis.
5.
What is the main product of photosynthesis?
Correct Answer
D. Glucose
Explanation
The main product of photosynthesis is glucose, which serves as an energy storage molecule. Plants use glucose as a source of energy and a building block for growth. The synthesis of glucose from carbon dioxide and water during photosynthesis not only provides essential organic compounds but also releases oxygen as a byproduct, which is vital for aerobic respiration in both plants and animals.
6.
What process do both plants and animals use to release energy from food?
Correct Answer
A. Cellular respiration
Explanation
Cellular respiration is a process used by all plants and animals to release stored energy from glucose. During cellular respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and energy in the form of ATP (adenosine triphosphate). This process is crucial for maintaining the life processes of cells by providing the necessary energy to power cellular activities.
7.
Where does cellular respiration primarily occur?
Correct Answer
B. Mitochondria
Explanation
Cellular respiration primarily occurs in the mitochondria, the powerhouse of the cell. Mitochondria are specialized organelles that facilitate the conversion of energy stored in glucose into ATP through a series of chemical reactions known as the Krebs cycle and oxidative phosphorylation. The efficiency of mitochondria in energy conversion underscores their vital role in cellular metabolism and energy production.
8.
What is the main byproduct of cellular respiration?
Correct Answer
C. Carbon dioxide
Explanation
The main byproduct of cellular respiration is carbon dioxide. This gas is produced during the Krebs cycle, where carbon from glucose is oxidized, and then released as waste from cells into the bloodstream, to be expelled through the respiratory system. The release of carbon dioxide is a necessary part of metabolic cycles in cells, balancing oxygen intake and maintaining acid-base homeostasis in the body.
9.
Which is a product of both photosynthesis and cellular respiration?
Correct Answer
A. Water
Explanation
Water is a product of both photosynthesis and cellular respiration. In photosynthesis, water molecules are split into oxygen, protons, and electrons during the light-dependent reactions, which are essential for glucose synthesis. In cellular respiration, water is formed as a byproduct when electrons combine with oxygen at the end of the electron transport chain, helping to stabilize the energy transfer and synthesis processes in cells.
10.
What does cellular respiration break down to release energy?
Correct Answer
C. Glucose
Explanation
In cellular respiration, glucose is the primary molecule broken down to release energy. This process, starting with glycolysis and continuing through the Krebs cycle and the electron transport chain, systematically extracts energy from the glucose molecule to synthesize ATP, providing the energy required for various cellular functions. The breakdown of glucose illustrates the central role of carbohydrates in cellular energy cycles, highlighting the interconnectedness of metabolism and energy production in life.