Which of the following statements best describe the function of a buffer?

Spirometry is a common pulmonary function test that measures pulmonary ventilation, specifically assessing the volume and flow of air that can be inhaled and exhaled from the lungs. It provides important information about lung function and can help diagnose various respiratory conditions.

The other options do not relate to spirometry:

• A. Urinary capacity of the bladder: This is measured by urodynamics or bladder capacity tests, not spirometry.
• B. Volume of blood in the body: This can be estimated using different methods, such as dilution techniques or imaging, but not spirometry.
• D. Number of turns in the small intestine: This relates to the anatomy and function of the digestive system and is not measured by spirometry.

Thus, spirometry specifically evaluates how well the lungs are functioning in terms of air movement.

Transfer RNA (tRNA) is responsible for carrying amino acids to ribosomes during protein synthesis. Each tRNA molecule has a specific anticodon that matches a codon on the messenger RNA (mRNA) molecule. The tRNA molecule binds to the mRNA codon and brings the corresponding amino acid to the ribosome, where it is added to the growing polypeptide chain.

A buffer is a solution that resists changes in pH when small amounts of an acid or base are added. Buffers work by neutralizing added hydrogen ions (H⁺) or hydroxide ions (OH⁻), thereby maintaining a relatively stable pH. Buffers are made up of a weak acid and its conjugate base or a weak base and its conjugate acid.

• A. It decreases the pH of the solution: This is incorrect because a buffer does not always decrease pH; it resists changes in both directions.
• C. It causes the pH of a solution to become neutral: Incorrect because buffers do not necessarily make a solution neutral; they stabilize pH around a certain value.
• D. It permanently binds hydrogen ions: Incorrect as the binding is reversible, which is essential for maintaining pH balance.

Facial acne is commonly caused by the blockage and inflammation of the sebaceous glands. These glands are responsible for secreting sebum, an oily substance that helps to lubricate the skin and hair. When these glands become overactive, or their ducts are blocked by excess sebum and dead skin cells, it can lead to the formation of pimples, blackheads, or whiteheads, which are typical signs of acne.

• Sebaceous glands are found near hair follicles and are primarily responsible for acne when they become clogged.

The other options are not related to acne:

• A. Lacrimal glands: These produce tears and are associated with the eye, not the skin.
• B. Sudoriferous glands: These are sweat glands, which are involved in perspiration, not typically linked to acne.
• D. Ceruminous glands: These are found in the ear canal and produce earwax, not involved in facial skin health.

A frameshift mutation is a type of genetic mutation that involves the insertion or deletion of one or more nucleotides in a DNA sequence. This can cause a shift in the reading frame of the genetic code, resulting in a change in the amino acid sequence of the resulting protein. Frameshift mutations can have significant effects on the function of the protein and can lead to genetic disorders or diseases.

The scientific method is a systematic approach used to answer questions or test hypotheses about the natural world. The steps involved in the scientific method are:

1. Observation: This is the first step in the scientific method. It involves observing a phenomenon or a problem and gathering information about it.
2. Hypothesis: After making an observation, a scientist forms a hypothesis, which is a tentative explanation for the phenomenon or problem.
3. Prediction: Based on the hypothesis, the scientist makes a prediction about what will happen in an experiment or what they will observe.
4. Experimentation: The scientist designs and conducts an experiment to test the hypothesis and prediction.
5. Analysis: The data collected from the experiment are analyzed to determine if they support or refute the hypothesis.
6. Conclusion: Based on the analysis of the data, the scientist draws a conclusion about whether the hypothesis is supported or refuted.

Option b) is incorrect because it starts with hypothesis before observation. Option c) is incorrect because prediction comes before experimentation. Option d) is incorrect because hypothesis comes after observation and data collection.

In the given exothermic reaction:

CaO + H2O ⇌ Ca(OH)2 + heat

To increase the total yield of lime water (Ca(OH)₂), you can apply Le Chatelier's Principle, which states that if a dynamic equilibrium is disturbed, the system will shift in a direction that counteracts the disturbance.

• A. Continuously remove Ca(OH)₂: By removing the product (Ca(OH)₂) as it forms, the equilibrium will shift to the right, favoring the formation of more Ca(OH)₂. This is the most effective way to increase the yield.

The other options are less effective or counterproductive:

• B. Increase the temperature: Since the reaction is exothermic, increasing the temperature would shift the equilibrium to the left (toward the reactants), reducing the yield of Ca(OH)₂.
• C. Increase the pressure: This reaction does not involve gases, so changing the pressure would not significantly affect the equilibrium.
• D. Add an enzyme that can catalyze this reaction: While a catalyst speeds up the rate of reaction, it does not affect the equilibrium position or the total yield of products. It simply allows the system to reach equilibrium faster.

Thus, continuously removing Ca(OH)₂ is the best way to increase the total yield of lime water.

Exocrine glandular is not one of the four primary tissue types found in the human body. The four primary tissue types are epithelial, nervous, connective, and muscle.

The main difference between a solid and a liquid is their physical state and the way their particles are arranged. In a solid, the particles are tightly packed together and have a fixed position, which gives the solid a definite shape and volume. Solids are also characterized by their high density, low compressibility, and high thermal conductivity.

In contrast, the particles in a liquid are more loosely packed and can move around each other, which allows the liquid to take the shape of its container. Liquids have a definite volume but no fixed shape, which means they can be poured or spilled. Liquids also have a lower density than solids, are more compressible than solids, and have lower thermal conductivity than solids.

Option b) is incorrect because it describes the properties of a gas, not a liquid. Option c) is incorrect because solids and liquids have different physical properties. Option d) is incorrect because it describes the properties of a gas, not a liquid or a solid.

The perineum is the region of the body located between the pubic symphysis (in the front) and the coccyx (in the back). It includes the areas surrounding the openings for the urinary, digestive, and reproductive systems, such as the urethra, anus, and, in females, the vaginal opening.

The other options describe different areas of the body:

• A. The area on the back between the neck and the two shoulder blades refers to the upper back and shoulder region, not the perineum.
• C. The area between the nipples on the chest and the belly button describes the mid-torso, not the perineum.
• D. The area between the edges of the eyes and the chin describes the face, not the perineum.