Nokea
Which of the following substances is excreted by the sweat glands in response to the breakdown of proteins and the formation of ammonia?
- A. Lysozymes
- B. Water
- C. Urea
- D. Sebum
Correct Answer: C
Rationale: The correct answer is Urea. Sweat glands excrete urea in response to the breakdown of proteins and the formation of ammonia. Urea is a waste product formed in the liver by the breakdown of amino acids. It is then excreted by the kidneys in urine and by sweat glands through perspiration. Urea plays a vital role in the excretory process by helping eliminate nitrogenous wastes from the body and maintaining proper physiological balance.
You may also like to solve these questions
Which of the following structures is present in both prokaryotic and eukaryotic cells?
- A. Cell membrane
- B. Chromoplast
- C. Golgi apparatus
- D. Endoplasmic reticulum
Correct Answer: A
Rationale: The correct answer is the cell membrane (choice A). The cell membrane is a vital structure present in both prokaryotic and eukaryotic cells. It plays a crucial role as a selectively permeable barrier, controlling the movement of substances into and out of the cell. On the other hand, chromoplasts, Golgi apparatus, and endoplasmic reticulum are specific organelles found only in eukaryotic cells. Chromoplasts are responsible for pigment synthesis, Golgi apparatus is involved in protein processing and packaging, and endoplasmic reticulum is crucial for lipid synthesis and protein folding. Therefore, the cell membrane is the correct choice as it is the common feature shared by both prokaryotic and eukaryotic cells.
Which of the following molecules are found in substantial quantities in both the cell membrane and DNA?
- A. Nitrogenous bases
- B. Steroids
- C. Phosphate groups
- D. Lipids
Correct Answer: C
Rationale: Phosphate groups are crucial components of the DNA backbone, forming the phosphodiester bonds between nucleotides. In DNA, the phosphate group connects the 3' carbon of one nucleotide to the 5' carbon of the next nucleotide. In the cell membrane, phospholipids are the main components, with phosphate groups present in the hydrophilic head of the molecule. This key structural feature allows phospholipids to form the lipid bilayer that comprises the cell membrane. While nitrogenous bases are essential components of DNA, they are not found in substantial quantities in the cell membrane. Steroids are not typically abundant in either the cell membrane or DNA. Lipids, although present in the cell membrane, do not have the same substantial presence in DNA as phosphate groups do.
Which of the following tools can be used to measure the turbidity of a liquid by assessing the transmission of light through the sample?
- A. Spectrophotometer
- B. Microdensitometer
- C. Electrophoresis apparatus
- D. Centrifuge
Correct Answer: A
Rationale: A spectrophotometer is an instrument commonly employed to determine the amount of light absorbed by a substance in a liquid sample. Turbidity, the cloudiness or haziness of a liquid due to suspended particles, can be quantified using a spectrophotometer by analyzing the transmission of light through the sample. In contrast, a microdensitometer measures optical density, an electrophoresis apparatus separates macromolecules based on size and charge, and a centrifuge isolates substances according to density or size via centrifugal force. None of the alternative tools directly relate to assessing turbidity through light transmission, making option A, the spectrophotometer, the correct choice.
The breakdown of lactose in the small intestine is mediated by the enzyme lactase, and the products are galactose and glucose. Galactose and glucose are which of the following?
- A. Disaccharides
- B. Oligosaccharides
- C. Polysaccharides
- D. Monosaccharides
Correct Answer: D
Rationale: Galactose and glucose are both simple sugars consisting of single sugar units. Therefore, they are classified as monosaccharides. This makes option D the correct answer.
In a study that found two processes, process A and process B, to be correlated, which of the following statements is true for these processes?
- A. The study cannot indicate whether processes A and B have a negative relationship.
- B. The study does not indicate a causal relationship between the processes.
- C. The study cannot indicate whether processes A and B have a positive relationship.
- D. The study indicates that process A causes process B.
Correct Answer: B
Rationale: When two processes are found to be correlated, it means that they are related in some way, but correlation does not imply causation. The study establishes a statistical relationship between process A and process B, but it does not prove that one causes the other. Therefore, the study does not indicate a causal relationship between the processes. Choice B is the correct answer as it accurately reflects this limitation of the study's findings.