Which of the following elements is the most electronegative?

Which of the following Mendelian laws describes how pairs of alleles within genes separate and recombine separately from other genes?

Law of independent assortment.

Mendel’s law of independent assortment, his second law of heredity, expands on the law of segregation by stipulating that alleles that separate in the gamete stage do so independently of other genes.

Which of the following does NOT describe a sarcomere?

It completely surrounds the muscle fiber.

The sarcomere is the contractile unit of a muscle made up of fibrous protein filaments, actin and myosin. During contraction, the sarcomere shortens in length when actin and myosin slide past each other. The structure that surrounds the muscle fiber is called the sarcolemma.

Which of the following correctly pairs structure and function?

Stomach / chemical digestion.

The stomach is responsible for chemical digestion. As food contents enter the stomach, it mixes with digestive enzymes and hydrochloric acid to break down food. The muscular contractions, or segmentation, that the stomach muscles produce helps to move the food around and ensure it thoroughly mixes with the chemicals. While mechanical digestion (i.e. chewing) and chemical breakdown begins in the mouth, nutrient absorption does not occur until the food particles are small enough for absorption and this happens in the small intestine. The duodenum is a segment of the small intestine (where most nutrient absorption takes place). However, reabsorption of water happens in the large intestine, not the small intestine. The colon is a segment of the large intestine which is primarily responsible for reabsorption of water and some electrolytes. The absorption of glucose occurs mainly in the small intestine.

The codon for the amino acid methionine is AUG. Which anticodon would be found on the tRNA that carries methionine?

UAC

Each tRNA molecule has an anticodon that binds to the complementary codon on the mRNA strand. A bonds with U (not T, as in DNA), U bonds with A, and G bonds with C.

Which of the following are regions of the digestive system in which amylase is produced?

Pancreas and salivary glands.

Both the pancreas and salivary glands produce amylase, which is an enzyme that helps digest carbohydrates.

After air is inhaled through the mouth, nose, and throat, which of the following structures does it travel through?

Trachea.

The trachea, or windpipe, is a passageway for air as it moves from the mouth, nose, and throat to the bronchi.

Which of the following hormones are secreted directly by the hypothalamus?

Dopamine.

Of the hormones listed, only dopamine is secreted directly by the hypothalamus. The hypothalamus synthesizes and releases dopamine into the hypothalamic-pituitary portal system, which then acts on the anterior pituitary gland to regulate the secretion of other hormones such as prolactin.
Calcitonin is secreted by the thyroid gland, not the hypothalamus. Melatonin is secreted by the pineal gland, which is located in the brain but not part of the hypothalamus-pituitary axis. Oxytocin is synthesized in the hypothalamus but is then transported to and released by the posterior pituitary gland.

A scientist designs an experiment to test the hypothesis that exposure to more sunlight will increase the growth rate of elodea, a type of aquatic plant. The scientist has accumulated data from previous experiments that identify the average growth rate of elodea exposed to natural sunlight in the wild.
In the experiment setup, there are three tanks housing ten elodea each. Tank A is positioned in front of a window to receive natural sunlight similar to what elodea are exposed to; tank B is positioned in front of the same window but has an additional sunlight-replicating lamp affixed to it; and tank C is positioned in a dark corner with no exposure to natural sunlight.
Which of the following types of experiments is described above?

Controlled experiment.

A controlled experiment requires researchers to compare an experimental group with a control group while controlling all variables except for the independent variable, which the researcher manipulates to test the hypothesis.

Which of the following is a decomposition reaction?

H2CO3 → H2O + CO2

This is a decomposition reaction where one reactant breaks apart into two products.

A well-controlled experiment was conducted where researchers noted that a new antibiotic eliminated a bacterial sinus infection. Which of the following can be inferred from this result?

The medication killed the bacteria responsible for the sinus infection.

The most likely explanation for the elimination of the sinus infection is that the medicine killed the bacteria. Antibiotics are drugs that kill or halt the growth of bacteria, so this is the most likely explanation for the elimination of the sinus infection since the antibiotics do not have an influence on a person’s allergies or DNA.

Oxygen is exchanged between blood and tissues at which of the following areas?

Capillaries.

Capillaries are very small blood vessels found where veins and arteries meet. They are the site of material exchange.

A physician makes a diagnosis of a right tibia fracture. Which part of the body is affected?

Lower leg.

The tibia is a bone in the lower leg.

Which of the following is a function of the epidermis?

Protects underlying tissues from abrasions, heat, microbes, and chemicals.

The epidermis, as the outermost layer of the skin, protects underlying tissues from abrasions, heat, microbes, and chemicals. It functions as a major component of the innate immune system (the “general” immune system that targets anything seen as “foreign”). It is avascular, so it does not contain blood vessels. Lipid-containing cells are found in the subcutaneous layer.

Which of the following cell types that are present in the epidermis serve as a sensory function and occur deep in the epidermis?