A myocardial infarction affects which of the following blood vessels of the heart?

 

The glomerulus is the main filtering unit of the kidney.

It is formed by a network of small blood vessels (capillaries) enclosed within a sac called the Bowman’s capsule.

The blood supply to the glomerulus is provided via the afferent arteriole.

The blood then flows through the capillary network, where it gets filtered, and then leaves the glomerulus via the efferent arteriole.

Choice B.

Proximal tubule is not correct because it is where the ultrafiltrate collected in the Bowman’s space drains directly into.

Choice C.

Distal tubule is not correct because it is not mentioned in relation to blood exiting the glomerulus.

Choice D.

Afferent arteriole is not correct because it provides blood supply to the glomerulus.

Amino acids have a unique structure consisting of an amino group (-NH3⁺) and a carboxyl group (-COO⁻) attached to a central carbon (called the α-carbon). At physiological pH (around 7.4), these functional groups often exist in their ionized forms:

• The amino group (-NH3⁺) is positively charged, acting as a proton acceptor (a base).
• The carboxyl group (-COO⁻) is negatively charged, acting as a proton donor (an acid).

This results in a zwitterion — a molecule with both a positive and a negative charge. Because amino acids can accept or donate protons depending on the pH of their environment, they have buffering capacity. This means they can resist changes in pH by stabilizing the concentration of hydrogen ions (H⁺).

Why Other Options Are Incorrect:

• A. Monosaccharides: These are simple sugars without ionizable functional groups, so they cannot act as buffers.
• B. Ribonucleotides and D. Deoxyribonucleotides: While nucleotides have phosphate groups that can donate protons, they lack the dual positive and negative functional groups necessary for the strong buffering effect seen in amino acids.

Therefore, amino acids are the correct choice because their zwitterionic nature provides them with excellent buffering capacity.

Heavier objects fall faster than lighter objects.

The data in the table shows that as the number of filters (and therefore the mass) increases, the terminal velocity also increases.

This means that the heavier objects (with more filters) are falling faster than the lighter objects (with fewer filters).

Choice A is not supported by the data in the table as much as it is true.

Terminal velocity is indeed when the force of gravity is equal to air resistance, but this definition does not provide any information about the relationship between mass and terminal velocity.

Choice B is also not supported by the data in the table.

The data does not provide any information about the time it takes for an object to reach terminal velocity.

Choice D is not supported by the data in the table.

The data shows that as the number of filters increases, the terminal velocity also increases.

This means that the greater the number of filters, the greater (not smaller) the terminal velocity.

The polarity of water molecules explains its solvent abilities for certain substances.

Water is a polar molecule because it has a partial positive charge on one end and a partial negative charge on the other end due to the unequal sharing of electrons between the oxygen and hydrogen atoms.

This polarity allows water to dissolve other polar substances and ionic compounds.

Choice A.

Kinetic energy of liquid water molecules is not the correct answer because kinetic energy refers to the energy of motion and does not directly explain water’s solvent abilities.

Choice B.

High specific heat is not the correct answer because specific heat refers to the amount of heat required to raise the temperature of a substance and does not directly explain water’s solvent abilities.

Choice C.

High surface tension is not the correct answer because surface tension refers to the cohesive forces between liquid molecules and does not directly explain water’s solvent abilities.

Diameter.

The diameter is the measurement of a straight line passing through the center of a circle and connecting two points on its circumference.

In this case, the line across the center of the cell represents the diameter of the cell.

Choice A, Area, is not the correct answer because area refers to the amount of space inside a two-dimensional shape.

Choice C, Volume, is not the correct answer because volume refers to the amount of space occupied by a three-dimensional object.

Choice D, Radius, is not the correct answer because radius refers to the distance from the center of a circle to its circumference and is half the length of the diameter.

Control.

A control group is a group in an experiment that does not receive the treatment or manipulation being tested and is used as a benchmark to measure how the other tested subjects do.

The control group is used to minimize the effects of all variables except the independent variable.

This allows researchers to determine if changes in the dependent variable are due to the manipulation of the independent variable or if they are due to some other factor.

Choice A.

Responding is not the correct answer because it refers to the dependent variable, which is the variable that is being measured in an experiment.

Choice B.

Manipulated is not the correct answer because it refers to the independent variable, which is the variable that is being manipulated in an experiment.

Choice D.

Variable is not the correct answer because it refers to any factor that can change in an experiment and can include both independent and dependent variables.

Sodium bicarbonate neutralizes the acidity of chyme.

The pancreas secretes large amounts of sodium bicarbonate, which protects the duodenum by neutralizing the acid that comes from the stomach.

This compound helps neutralize stomach acid generated during the digestive process.

Choice A is incorrect because sodium bicarbonate is not a protease that digests carbohydrates.

Proteases are enzymes that break down proteins, while sodium bicarbonate is a chemical compound that helps neutralize stomach acid.

Choice B is incorrect because sodium bicarbonate does not stimulate the pyloric sphincter.

The pyloric sphincter is a ring of smooth muscle that separates the stomach from the duodenum and regulates the passage of partially digested food (chyme) into the small intestine.

Choice C is incorrect because sodium bicarbonate does not inhibit peristalsis.

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.

Bag mass change is the dependent variable in this experiment.

In an experiment, the dependent variable is the variable that is being measured and is expected to change in response to changes in the independent variable(s).

In this case, the bag mass change is being measured and is expected to change in response to changes in the independent variable (sucrose concentration).

Choice A is incorrect because duration is not a variable in this experiment.

Choice B is incorrect because temperature is not a variable in this experiment.

Choice D is incorrect because sucrose concentration is an independent variable, not a dependent variable.

An independent variable is a variable that is manipulated by the experimenter to see how it affects the dependent

As a solid turns to a liquid, the particles become less ordered and more free to move around.

Choice B is not correct because particles have an increase in mobility as a solid turns to a liquid.

Choice C is not correct because particles move further apart as a solid turns to a liquid.

Choice D is not correct because intermolecular forces between particles become weaker as a solid turns to a liquid.

Calcium ions play a crucial role in initiating muscle contraction.

When a muscle cell is stimulated to contract by an action potential, calcium channels open in the sarcoplasmic membrane and release calcium into the sarcoplasm.

Some of this calcium attaches to troponin, which causes it to change shape.

This shape change exposes binding sites for myosin on the actin filaments.

Myosin’s binding to actin causes crossbridge formation, and contraction of the muscle begins.

The other ions mentioned in the question do not have this specific role in muscle contraction.

Potassium ions are important for maintaining the resting membrane potential of cells, but they do not bind to the troponin complex.

Phosphorus ions are important for energy metabolism, but they do not bind to the troponin complex.

Sodium ions are important for generating action potentials, but they do not bind to the troponin complex.