Nokea
Tonicity refers to the movement of:
- A. Water
- B. Solute
- C. Cells
- D. None of the above
Correct Answer: A
Rationale: Tonicity is a term used to describe the relative concentration of solutes inside and outside of a cell. When a solution is hypertonic, it has a higher concentration of solutes outside the cell, causing water to move out of the cell. When a solution is hypotonic, it has a lower concentration of solutes outside the cell, causing water to move into the cell. Therefore, tonicity primarily affects the movement of water across a cell membrane.
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Which of the following organelles is responsible for producing cell energy?
- A. Mitochondrion and chloroplast
- B. Mitochondrion and nucleus
- C. Chloroplast and nucleus
- D. Chloroplast and lysosome
Correct Answer: A
Rationale: The correct answer is A: Mitochondrion and chloroplast. Mitochondria are known as the powerhouse of the cell as they produce the majority of a cell's energy in the form of ATP (adenosine triphosphate) through aerobic respiration. Chloroplasts, found in plant cells, are responsible for photosynthesis, a process that converts light energy into chemical energy in the form of glucose. Therefore, both mitochondria and chloroplasts play crucial roles in energy production in cells.
What molecules are unmetabolized by the body, but are used to increase reaction rates?
- A. Sugars.
- B. Proteins.
- C. Enzymes.
- D. Lipids.
Correct Answer: C
Rationale: The correct answer is C: Enzymes. Enzymes are molecules that increase reaction rates by acting as catalysts in biochemical reactions. They are not metabolized by the body, meaning they remain unchanged after facilitating the reactions. Sugars (choice A), proteins (choice B), and lipids (choice D) are all metabolized by the body to provide energy or building blocks for various cellular functions, unlike enzymes which remain unchanged. Therefore, enzymes are the only choice that fits the description of being unmetabolized molecules used to increase reaction rates.
Which term means a group of similar cells combined to perform a common function?
- A. Tissue
- B. Organism
- C. System
- D. Organ
Correct Answer: A
Rationale: The correct answer is 'Tissue.' Tissue is a group of similar cells that work collectively to carry out a specific function. These specialized cells combine to form tissues, which further combine to create organs. Organs then collaborate within systems in the body to maintain balance (homeostasis) and perform various functions such as digestion, circulation, and respiration.
When the genotype consists of a dominant and a recessive allele, the phenotype will be like the....................allele.
- A. Dominant
- B. Recessive
- C. Both
- D. Neither
Correct Answer: A
Rationale: When an individual possesses a genotype with both a dominant and a recessive allele, the dominant allele will dictate the phenotype. Dominant alleles are expressed over recessive alleles in heterozygous individuals, leading to the phenotype resembling the dominant allele's characteristics.
Which of the following is a protein?
- A. cellulose
- B. hemoglobin
- C. estrogen
- D. ATP
Correct Answer: B
Rationale: Hemoglobin is the correct answer as it is a protein. Proteins are large, complex molecules composed of amino acids that are essential for various structural and functional roles in the body. Hemoglobin, specifically, is a protein found in red blood cells and is responsible for carrying oxygen from the lungs to different parts of the body, highlighting its crucial role in oxygen transportation.