Nokea
Which technology allows scientists to directly edit the human genome?
- A. Polymerase Chain Reaction (PCR)
- B. Gel electrophoresis
- C. DNA sequencing
- D. CRISPR-Cas9
Correct Answer: D
Rationale: CRISPR-Cas9 is the correct answer. A) Polymerase Chain Reaction (PCR) is used for amplifying specific DNA segments, not directly editing the human genome. B) Gel electrophoresis is for separating DNA fragments by size, not for genome editing. C) DNA sequencing determines DNA nucleotide order but does not directly edit the genome. D) CRISPR-Cas9 technology enables precise modifications in the DNA of organisms, including humans. It guides the Cas9 enzyme to specific genome locations for targeted edits, revolutionizing genetic research and offering various applications in gene editing and therapy. Unlike the other techniques mentioned, CRISPR-Cas9 is specifically designed to make changes in the genetic code itself, making it a powerful tool for genetic manipulation.
You may also like to solve these questions
Which of the following represents a form of potential energy?
- A. A moving car
- B. A spinning top
- C. A raised hammer
- D. A rolling ball
Correct Answer: C
Rationale: A raised hammer represents potential energy as it possesses stored energy due to its position above the ground. When the hammer falls, this potential energy is converted into kinetic energy as it moves. In contrast, options A, B, and D involve objects already in motion, representing kinetic energy. Choice A, a moving car, is in motion and has kinetic energy. Choice B, a spinning top, is also in motion and exhibits kinetic energy. Choice D, a rolling ball, is already moving and thus has kinetic energy. Therefore, only choice C, a raised hammer, is the correct representation of potential energy among the given options.
Which term refers to the act of inhaling foreign objects into the airway?
- A. Expiration
- B. Respiration
- C. Aspiration
- D. Inhalation
Correct Answer: C
Rationale: Among the options provided, aspiration is the term that specifically refers to the act of inhaling foreign objects into the airway. Expiration refers to breathing out, respiration is the overall process of gas exchange in the body, and inhalation is the act of breathing in air or other substances into the lungs. Therefore, the correct answer is C, aspiration. It is crucial to understand these terms in the context of airway management and respiratory care to ensure proper identification and treatment of related conditions.
Sebaceous glands, located in the dermis, secrete an oily substance called:
- A. Sweat
- B. Sebum
- C. Cerumen
- D. Mucus
Correct Answer: B
Rationale: Sebaceous glands are responsible for secreting an oily substance called sebum, not sweat, cerumen, or mucus. Sebum plays a vital role in lubricating and waterproofing the skin and hair, preventing them from drying out. Sweat glands produce sweat to regulate body temperature. Cerumen is the medical term for earwax, produced by ceruminous glands in the ear canal, while mucus is a slimy substance that protects and lubricates body tissues. Therefore, the correct answer is B: Sebum, as it is the oily substance secreted by sebaceous glands.
Which statement is true regarding aromatic compounds?
- A. Contain a ring structure with alternating single and double bonds
- B. Readily undergo addition reactions
- C. Are easily broken down by water
- D. Do not contain any pi (π) bonds
Correct Answer: A
Rationale: Aromatic compounds contain a ring structure with alternating single and double bonds, known as a benzene ring. This alternating pattern of bonds gives aromatic compounds their stability and unique properties. Due to this resonance, aromatic compounds are less reactive towards addition reactions. Water does not easily break down aromatic compounds due to their stability from the delocalized electrons in the ring structure. Therefore, the correct statement is that aromatic compounds contain a ring structure with alternating single and double bonds, providing them with stability and unique properties. Choices B, C, and D are incorrect. Aromatic compounds do not readily undergo addition reactions (B), are not easily broken down by water (C), and do contain pi (π) bonds due to the presence of the alternating single and double bonds in the ring structure (D).
What type of bond links amino acids together to form proteins?
- A. Hydrogen bond
- B. Ionic bond
- C. Disulfide bond
- D. Covalent bond
Correct Answer: D
Rationale: Amino acids are linked together by covalent bonds to form proteins. Specifically, the bond that links amino acids together is called a peptide bond, which is a type of covalent bond. The peptide bond forms between the amino group of one amino acid and the carboxyl group of another amino acid, resulting in the formation of a peptide chain. While hydrogen bonds, ionic bonds, and disulfide bonds are important for protein structure and stability, the primary bond responsible for linking amino acids in a protein chain is the covalent peptide bond. Hydrogen bonds are involved in maintaining the secondary structure of proteins, such as alpha helices and beta sheets. Ionic bonds and disulfide bonds contribute to tertiary and quaternary structures of proteins by stabilizing interactions between different parts of the protein or between different protein subunits, respectively.