Nursing Elites

1. Which structure, located between the pons and the spinal cord, plays a crucial role in coordinating movements, maintaining balance, and posture?

• A. Thalamus
• B. Medulla oblongata
• C. Cerebellum
• D. Hypothalamus

Correct answer: C

Rationale: The correct answer is the cerebellum. The cerebellum, located between the pons and the spinal cord, is responsible for coordinating movements, maintaining balance, and posture. The thalamus functions in relaying sensory and motor signals to the cerebral cortex, the medulla oblongata controls vital autonomic functions such as breathing and heart rate, and the hypothalamus regulates various bodily functions like temperature and hunger. Therefore, the cerebellum is the structure that specifically handles coordination, balance, and posture.

2. Where does most of the chemical digestion and absorption of nutrients occur?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: C

Rationale: The small intestine is the primary site for both chemical digestion and absorption of nutrients in the digestive system. The lining of the small intestine is equipped with villi and microvilli, which significantly increase the surface area available for absorption. Enzymes from the pancreas and bile from the liver play crucial roles in further breaking down food into absorbable molecules that can pass through the intestinal wall into the bloodstream. While the stomach assists in mechanical breakdown and initial protein digestion, it is not the main site of nutrient absorption. The large intestine, on the other hand, mainly absorbs water and electrolytes from undigested food particles. The mouth aids in initial mechanical breakdown and some carbohydrate digestion, but the majority of nutrient absorption occurs in the small intestine, making it the correct answer.

3. What information does a genotype provide that a phenotype does not?

• A. The genotype necessarily includes the proteins coded for by its alleles.
• B. The genotype will always display an organism's recessive alleles.
• C. The genotype must include the organism's physical characteristics.
• D. The genotype indicates what an organism's parents looked like.

Correct answer: A

Rationale: The genotype provides information about the specific genetic makeup of an organism, including the alleles it possesses for a particular trait. This information is not always directly reflected in the phenotype, which is the observable physical characteristics of an organism. The genotype determines the proteins coded for by its alleles, but the phenotype is the expression of those proteins in the organism's traits. Therefore, the genotype necessarily includes the proteins coded for by its alleles, a detail not provided solely by the phenotype.\nChoice B is incorrect because the genotype may include dominant alleles as well, not just recessive ones. Choice C is incorrect because the genotype refers to genetic information, not physical characteristics. Choice D is incorrect because the genotype does not directly indicate what an organism's parents looked like; it primarily describes the genetic information inherited from parents.

4. What is the building block of DNA?

• A. Amino acid
• B. Nucleotide
• C. Phosphate group
• D. Fatty acid

Correct answer: B

Rationale: - Amino acids are the building blocks of proteins, not DNA. - Nucleotide is the correct building block of DNA. A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). - The option 'C) Phosphate group' is incorrect as it is only part of a nucleotide, not the complete building block of DNA. - Fatty acids are not the building blocks of DNA; they are a type of lipid molecule.

5. What happens when an atom loses an electron?

• A. It forms a molecule.
• B. It gains a positive charge and becomes an ion.
• C. It alters its elemental identity.
• D. No change occurs; it remains neutral.

Correct answer: B

Rationale: When an atom loses an electron, it gains a positive charge and becomes an ion. This occurs because the number of protons in the atom exceeds the number of electrons, leading to a positive charge. Therefore, the atom undergoes a transformation into an ion by losing an electron. Choice A is incorrect because losing an electron does not result in the formation of a molecule, as molecules are made up of bonded atoms. Choice C is incorrect because losing an electron does not change the fundamental identity of the atom; it only changes its charge. Choice D is incorrect because losing an electron causes the atom to become positively charged, altering its neutrality.

Similar Questions