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OH Cosmetology study materials
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OH Cosmetology practice questions

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Question 1Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which process uses a chemical agent to destroy most microorganisms on a hard, nonporous surface such as a manicure table?

  1. Sanitation
  2. Sterilization
  3. Disinfection Correct answer.
  4. Preservation

Explanation

Disinfection destroys most pathogenic microorganisms on hard, nonporous surfaces, but it does not necessarily destroy bacterial spores. Sterilization is a higher level that destroys all microbial life, while sanitation only removes visible debris and reduces some microorganisms.

Question 2Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which layer of the skin is the thin, outermost layer that contains no blood vessels?

  1. Dermis
  2. Epidermis Correct answer.
  3. Papillary layer
  4. Subcutaneous layer

Explanation

The epidermis is the outermost skin layer and is avascular, receiving nourishment from the dermis beneath it. The dermis contains blood vessels, nerves and glands, and the subcutaneous layer is the fatty layer below the dermis.

Question 3Scientific Concepts (infection control, anatomy and physiology, chemistry)

A solution with a pH of 3 is best described as:

  1. Slightly alkaline
  2. Acidic Correct answer.
  3. Neutral
  4. Strongly alkaline

Explanation

The pH scale runs from 0 to 14, with 7 being neutral, values below 7 acidic and values above 7 alkaline. A pH of 3 is well below 7, so the solution is acidic.

Question 4Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which type of bacteria is spherical or round in shape?

  1. Spirilla
  2. Bacilli
  3. Spores
  4. Cocci Correct answer.

Explanation

Cocci are round bacteria that may appear singly or in clusters and chains. Bacilli are rod-shaped and spirilla are corkscrew-shaped, while spores are a dormant, resistant form rather than a shape category.

Question 5Scientific Concepts (infection control, anatomy and physiology, chemistry)

The visible body of the nail that rests on the nail bed is called the:

  1. Lunula
  2. Nail fold
  3. Nail matrix
  4. Nail plate Correct answer.

Explanation

The nail plate is the visible nail body that sits on and is attached to the nail bed. The matrix is the hidden area where nail cells are produced, and the lunula is the whitish half-moon at the base of the plate.

Question 6Scientific Concepts (infection control, anatomy and physiology, chemistry)

Water is often called the universal solvent because:

  1. It freezes at 0 degrees Celsius
  2. It has a neutral pH
  3. It dissolves many substances Correct answer.
  4. It is made of hydrogen and oxygen

Explanation

A solvent is a substance that dissolves another substance, and water dissolves a wider variety of substances than most other liquids. Its composition, neutral pH and freezing point describe other properties of water, not its dissolving ability.

Question 7Scientific Concepts (infection control, anatomy and physiology, chemistry)

What should a cosmetologist do before and after performing a service on each client to help prevent the spread of infection?

  1. Wipe the hands on a clean towel
  2. Wash hands thoroughly with soap and water Correct answer.
  3. Spray the hands with a surface disinfectant
  4. Apply hand lotion to protect the skin

Explanation

Thorough handwashing with soap and water is the single most important step in preventing the spread of infection between clients. Surface disinfectants are not formulated for skin, and lotion or dry toweling does not remove pathogens.

Question 8Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which bone forms the forehead?

  1. Parietal bone
  2. Occipital bone
  3. Frontal bone Correct answer.
  4. Temporal bone

Explanation

The frontal bone forms the forehead and the upper part of the eye sockets. The parietal bones form the crown and upper sides of the head, the temporal bones lie near the ears, and the occipital bone forms the back of the skull.

Question 9Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which piece of salon equipment uses steam under pressure to destroy all microorganisms, including spores, on implements?

  1. Ultraviolet sanitizer
  2. Ultrasonic cleaner
  3. Dappen dish
  4. Autoclave Correct answer.

Explanation

An autoclave sterilizes implements by exposing them to steam under pressure, which destroys all microbial life including spores. An ultrasonic cleaner only removes debris, and a UV sanitizer reduces surface organisms without reliably sterilizing.

Question 10Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which of the following is a quaternary ammonium compound used as a salon disinfectant?

  1. Sodium hypochlorite
  2. Hydrogen peroxide solution
  3. Benzalkonium chloride Correct answer.
  4. Isopropyl alcohol

Explanation

Quaternary ammonium compounds, commonly called quats, include benzalkonium chloride and are widely used because they are broad-spectrum and low in toxicity on salon surfaces. Sodium hypochlorite is a chlorine-releasing bleach with different handling requirements.

Question 11Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which of these is a bloodborne pathogen that attacks the body's immune system?

  1. HIV Correct answer.
  2. Pediculosis capitis
  3. Tinea pedis
  4. Streptococcus pyogenes

Explanation

HIV is a bloodborne virus that destroys cells of the immune system, chiefly helper T cells. Tinea pedis is a fungus, streptococcus is a bacterium spread mainly by contact and droplets, and pediculosis is an infestation by head lice.

Question 12Scientific Concepts (infection control, anatomy and physiology, chemistry)

Ringworm of the foot, a fungal infection that cosmetologists may encounter, is called:

  1. Tinea pedis Correct answer.
  2. Folliculitis
  3. Pediculosis capitis
  4. Impetigo

Explanation

Tinea pedis, or athlete's foot, is a contagious fungal infection of the skin of the foot. Pediculosis is a lice infestation, folliculitis is inflammation of hair follicles, and impetigo is a bacterial skin infection.

Question 13Scientific Concepts (infection control, anatomy and physiology, chemistry)

Where can a salon employee find a chemical product's hazard information, first-aid measures and safe handling instructions?

  1. Client record card
  2. Safety Data Sheet Correct answer.
  3. Appointment book
  4. State board license certificate

Explanation

The Safety Data Sheet, formerly called the MSDS, is supplied by the manufacturer and summarizes a product's hazards, safe handling, and emergency measures. Salons are required to keep these sheets available for the products they use.

Question 14Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which layer of the hair shaft is made of overlapping, transparent scales that protect the inner layers?

  1. Cuticle Correct answer.
  2. Cortex
  3. Medulla
  4. Dermal papilla

Explanation

The cuticle is the outermost layer of the hair shaft and consists of overlapping scales that shield the cortex and medulla. The cortex holds melanin and gives hair its strength and elasticity, while the medulla is the innermost core.

Question 15Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which muscle closes the jaw for chewing?

  1. Occipitalis
  2. Masseter Correct answer.
  3. Trapezius
  4. Procerus

Explanation

The masseter is one of the muscles of mastication and raises the lower jaw to close the mouth. The occipitalis draws the scalp backward, the trapezius moves the shoulders, and the procerus moves the skin between the eyebrows.

Question 16Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which nerve is the chief sensory nerve of the face, also known as the trifacial nerve?

  1. Brachial plexus nerve
  2. Facial nerve
  3. Trigeminal nerve Correct answer.
  4. Occipital nerve

Explanation

The trigeminal, or fifth cranial nerve, carries sensation from the face, head and teeth and also supplies motor fibers to the chewing muscles. The facial nerve is the chief motor nerve of the face, while the occipital and brachial nerves serve other areas.

Question 17Scientific Concepts (infection control, anatomy and physiology, chemistry)

In the systemic circulation, which blood vessels carry oxygenated blood away from the heart?

  1. Arteries Correct answer.
  2. Capillaries
  3. Veins
  4. Lymphatic vessels

Explanation

Arteries are the vessels that carry blood away from the heart, and in the systemic circulation that blood is oxygenated. Veins return blood to the heart, capillaries allow exchange with tissues, and lymphatic vessels carry lymph.

Question 18Scientific Concepts (infection control, anatomy and physiology, chemistry)

A blend of two or more immiscible liquids, held together by an emulsifying agent, is called a(n):

  1. Compound
  2. Suspension
  3. Solution
  4. Emulsion Correct answer.

Explanation

In an emulsion, liquids that would not normally mix, such as oil and water, are dispersed in one another with the help of an emulsifier; many lotions and creams are emulsions. A solution is a stable mixture of dissolved substances, and a suspension contains larger particles that settle.

Question 19Scientific Concepts (infection control, anatomy and physiology, chemistry)

A chemical reaction in which a substance combines with oxygen is called:

  1. Oxidation Correct answer.
  2. Neutralization
  3. Reduction
  4. Saponification

Explanation

Oxidation is a reaction in which a substance gains oxygen or loses hydrogen, such as when a product darkens or a metal corrodes. Reduction is the opposite process, neutralization is an acid-base reaction, and saponification is the reaction that forms soap.

Question 20Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which type of tissue covers and protects body surfaces and lines internal organs and cavities?

  1. Nervous tissue
  2. Connective tissue
  3. Epithelial tissue Correct answer.
  4. Muscle tissue

Explanation

Epithelial tissue forms the protective covering of the skin and lines internal organs, cavities and ducts. Connective tissue supports and binds structures, muscle tissue contracts, and nervous tissue transmits impulses.

Question 21Scientific Concepts (infection control, anatomy and physiology, chemistry)

A salon dilutes a hospital-grade disinfectant with more water than the label specifies. What is the most likely consequence?

  1. The solution will need a shorter contact time
  2. The solution will sterilize the implements
  3. The solution may fail to kill pathogens at the labeled level Correct answer.
  4. The solution will become more effective as it spreads

Explanation

Disinfectants are formulated to be effective only at the labeled dilution, and overdiluting lowers the concentration of the active ingredient below the level needed to kill pathogens. Weakening the solution never shortens the required contact time and cannot sterilize implements.

Question 22Scientific Concepts (infection control, anatomy and physiology, chemistry)

Why should porous items such as wooden sticks and porous nail files be discarded after use rather than disinfected?

  1. They discolor when soaked in disinfectant solutions
  2. They are cheaper to replace than to disinfect thoroughly
  3. Disinfectants cannot penetrate pores to reach microbes Correct answer.
  4. They lose their shape when exposed to moisture

Explanation

Porous materials absorb moisture and debris, and microorganisms can become trapped deep within the pores where a disinfectant solution cannot reliably reach them. For this reason, porous implements are classified as single-use and must be discarded after each client.

Question 23Scientific Concepts (infection control, anatomy and physiology, chemistry)

A client develops redness and stinging after a product with a high pH is applied. Which protective property of the skin is most directly compromised?

  1. Keratinization of the nail matrix and plate
  2. The subcutaneous fat that cushions and insulates
  3. Melanin production in the basal layer of the epidermis
  4. The acid mantle that helps control skin bacteria Correct answer.

Explanation

Sebum and sweat form a slightly acidic film on the skin known as the acid mantle, which helps keep skin pH stable and inhibits bacteria. Alkaline products neutralize this film, leaving skin dry, irritated and more susceptible to infection.

Question 24Scientific Concepts (infection control, anatomy and physiology, chemistry)

A terminal hair is cut in cross-section. Which sequence lists its layers from the innermost to the outermost?

  1. Cuticle, cortex, medulla
  2. Medulla, cuticle, cortex
  3. Medulla, cortex, cuticle Correct answer.
  4. Cortex, medulla, cuticle

Explanation

The hair shaft has three layers: the medulla at the center, the cortex in the middle, and the cuticle on the outside. The cortex carries the melanin that gives hair its color and much of its strength.

Question 25Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which statement correctly distinguishes a suspension from a solution?

  1. It is a chemical compound formed from two elements
  2. It contains only gases dissolved in a liquid
  3. It is a uniform mixture that will not separate on standing
  4. Its particles settle and must be shaken before use Correct answer.

Explanation

In a suspension, larger particles are dispersed but not dissolved, so they settle to the bottom over time and the product must be shaken before use. A solution is uniform and stable because its particles are completely dissolved.

Question 26Scientific Concepts (infection control, anatomy and physiology, chemistry)

A tick or mosquito that carries a disease-causing organism from one host to another is called a:

  1. Fomite
  2. Vector Correct answer.
  3. Host
  4. Spore

Explanation

A vector is a living organism, such as an insect or arthropod, that transmits a pathogen from one host to another. Fomites are inanimate objects that can carry pathogens, and spores are a resistant form of certain bacteria.

Question 27Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which of these is the largest organ of the human body?

  1. Skin Correct answer.
  2. Brain
  3. Lung
  4. Liver

Explanation

The skin is the body's largest organ by surface area and weight, forming the outer covering of the body. It serves as a barrier against pathogens, injury, and water loss.

Question 28Scientific Concepts (infection control, anatomy and physiology, chemistry)

At room temperature, a solution with a pH of 7 is best described as:

  1. Slightly acidic
  2. Neutral Correct answer.
  3. Strongly alkaline
  4. Slightly alkaline

Explanation

The pH scale runs from 0 to 14, with 7 in the middle representing a neutral solution in which hydrogen ions and hydroxide ions are balanced. Values below 7 are acidic and values above 7 are alkaline.

Question 29Scientific Concepts (infection control, anatomy and physiology, chemistry)

The branch of science that studies the structure of the human body and the relationship of its parts is called:

  1. Physiology
  2. Histology
  3. Anatomy Correct answer.
  4. Biology

Explanation

Anatomy is the study of body structure, including the form, position, and relationships of organs and tissues. Physiology, by contrast, deals with how those structures function.

Question 30Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which statement correctly contrasts disinfection with sterilization?

  1. Sterilization is performed only on porous salon items.
  2. Disinfection destroys bacterial spores, but sterilization does not.
  3. Disinfection is simply sterilization carried out with heat.
  4. Sterilization destroys spores, but disinfection may not. Correct answer.

Explanation

Sterilization is the process that destroys all microbial life, including highly resistant bacterial spores. Disinfection destroys most microorganisms on hard, nonporous surfaces but does not reliably kill spores.

Question 31Scientific Concepts (infection control, anatomy and physiology, chemistry)

A client's scalp shows small, pus-filled bumps centered on hair follicles, and the cosmetologist suspects a staphylococcal infection. This condition is:

  1. Seborrheic dermatitis
  2. Pediculosis
  3. Tinea barbae
  4. Folliculitis Correct answer.

Explanation

Folliculitis is an inflammation of hair follicles, often caused by Staphylococcus bacteria, that appears as red, pus-filled bumps around the follicle opening. It is contagious and the service should be declined and the client referred for medical care.

Question 32Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which glands release hormones directly into the bloodstream to regulate body functions such as growth and metabolism?

  1. Lymph glands
  2. Sudoriferous glands
  3. Sebaceous glands
  4. Endocrine glands Correct answer.

Explanation

Endocrine glands are ductless glands that secrete hormones into the bloodstream so the hormones can travel to target organs. Sudoriferous and sebaceous glands are exocrine glands that release their secretions through ducts onto the skin.

Question 33Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which type of tissue carries messages between the brain and other parts of the body?

  1. Nerve tissue Correct answer.
  2. Connective tissue
  3. Muscle tissue
  4. Epithelial tissue

Explanation

Nerve tissue is composed of neurons that conduct electrical impulses, allowing communication between the brain and the rest of the body. Each of the four main tissue types has a distinct primary role.

Question 34Scientific Concepts (infection control, anatomy and physiology, chemistry)

A chemical reaction that releases heat energy as it proceeds is described as:

  1. Inert
  2. Catalytic
  3. Endothermic
  4. Exothermic Correct answer.

Explanation

An exothermic reaction gives off energy, usually as heat, to its surroundings. An endothermic reaction absorbs energy and tends to feel cool.

Question 35Scientific Concepts (infection control, anatomy and physiology, chemistry)

When atoms of two or more different elements bond chemically, the resulting substance is a(n):

  1. Mixture
  2. Suspension
  3. Solution
  4. Compound Correct answer.

Explanation

A compound is formed when atoms of different elements are joined by chemical bonds, and its properties differ from those of the original elements. Mixtures, solutions, and suspensions involve physical blending without new chemical bonds.

Question 36Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which of these is stored in the bones and released into the blood as the body needs it?

  1. Calcium Correct answer.
  2. Insulin
  3. Bile
  4. Glucose

Explanation

Bones serve as a reservoir for minerals, especially calcium and phosphorus, and release calcium into the blood when levels fall. This mineral storage is one of the skeletal system's key functions.

Question 37Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which blood vessels carry blood toward the heart and contain valves that prevent backflow?

  1. Arteries
  2. Capillaries
  3. Veins Correct answer.
  4. Ventricles

Explanation

Veins return blood to the heart and rely on one-way valves plus surrounding muscle action to keep blood moving against gravity. Arteries carry blood away from the heart under higher pressure and do not need valves.

Question 38Scientific Concepts (infection control, anatomy and physiology, chemistry)

Why must a reusable implement be cleaned and rinsed before it is placed in disinfectant?

  1. Cleaning removes all spores, making disinfection unnecessary.
  2. Disinfectants work only on tools that were sterilized first.
  3. Residue keeps the disinfectant from reaching the surface. Correct answer.
  4. Cleaning raises the pH of the disinfectant solution.

Explanation

Blood, oil, and product residue create a barrier that prevents the disinfectant from contacting the entire surface of the implement, reducing its effectiveness. Cleaning is therefore a required step before immersion in an EPA-registered hospital-grade disinfectant.

Question 39Scientific Concepts (infection control, anatomy and physiology, chemistry)

Compared with a solution that has a pH of 7, a solution with a pH of 5 contains:

  1. The same hydrogen ion concentration but a different color
  2. 100 times fewer hydrogen ions
  3. 2 times more hydrogen ions
  4. 100 times more hydrogen ions Correct answer.

Explanation

The pH scale is logarithmic, so each whole unit represents a tenfold change in hydrogen ion concentration. Moving two units toward the acid end (from 7 to 5) therefore means 10 times 10, or 100 times more hydrogen ions.

Question 40Scientific Concepts (infection control, anatomy and physiology, chemistry)

Which of these bones belongs to the appendicular skeleton rather than the axial skeleton?

  1. Frontal bone
  2. Scapula Correct answer.
  3. Vertebra
  4. Sternum

Explanation

The axial skeleton forms the central framework of the body and includes the skull, vertebral column, ribs, and sternum. The appendicular skeleton consists of the limbs plus the girdles that attach them, which includes the scapula.

Question 41Hair Care and Hair Services

What is the pH range of an acid-balanced shampoo?

  1. 4.5 to 5.5 Correct answer.
  2. 8.5 to 9.5
  3. 10.0 to 11.0
  4. 7.0 to 7.8

Explanation

Acid-balanced shampoos are formulated near the hair's natural pH of about 4.5 to 5.5, which helps keep the cuticle compact and minimizes moisture loss. Products in this range are mild and suitable for most clients.

Question 42Hair Care and Hair Services

Which layer of the hair shaft forms the tough, protective outer covering?

  1. Follicle
  2. Cortex
  3. Medulla
  4. Cuticle Correct answer.

Explanation

The cuticle is the outermost layer, made of overlapping scale-like cells that protect the inner structure and control what enters and leaves the hair. Its condition largely determines shine and porosity.

Question 43Hair Care and Hair Services

During which phase of the hair growth cycle does the hair actively grow?

  1. Telogen
  2. Anagen Correct answer.
  3. Exogen
  4. Catagen

Explanation

Anagen is the active growth phase, when cells in the hair bulb divide and the shaft lengthens. It is the longest phase and, on a healthy scalp, most hairs are in it at any given time.

Question 44Hair Care and Hair Services

Which test tells a cosmetologist how readily hair absorbs and holds moisture?

  1. Porosity test Correct answer.
  2. Patch test
  3. Elasticity test
  4. Strand test

Explanation

A porosity test shows how easily moisture passes into the hair, which guides product selection and service timing. Hair with a tight cuticle resists absorption, while a raised cuticle absorbs quickly but loses moisture.

Question 45Hair Care and Hair Services

Which layer of the hair contains melanin and gives the fiber its strength and elasticity?

  1. Cuticle
  2. Medulla
  3. Root sheath
  4. Cortex Correct answer.

Explanation

The cortex is the thick middle layer where melanin granules reside and where the protein chains that create strength and stretch live. Chemical and thermal services act primarily on this layer.

Question 46Hair Care and Hair Services

Hair that absorbs water quickly but also loses moisture readily and feels rough is best described as having what?

  1. Average density
  2. High porosity Correct answer.
  3. Normal porosity
  4. Low porosity

Explanation

High porosity means the cuticle is raised or damaged, so moisture enters fast but escapes just as fast, leaving hair dry and rough. These clients benefit from protein and moisturizing treatments rather than lightweight products.

Question 47Hair Care and Hair Services

When a wet strand stretches and returns to its original length without breaking, the hair shows what?

  1. Low elasticity
  2. Normal elasticity Correct answer.
  3. High porosity
  4. Excessive density

Explanation

Normal elasticity means the hair can stretch and return to shape, a sign that the cortex and its bonds are intact. Hair that snaps immediately has low elasticity and is unsuitable for strong chemical services.

Question 48Hair Care and Hair Services

Rinsing the hair with warm water during shampooing primarily helps to do what?

  1. Set a firm curl pattern
  2. Loosen sebum and debris Correct answer.
  3. Seal the cuticle shut
  4. Add protein to the cortex

Explanation

Warm water softens sebum and lifts away dirt, product residue, and perspiration so shampoo can work efficiently. Water that is too hot can strip moisture and irritate the scalp, so warm is preferred over hot.

Question 49Hair Care and Hair Services

Which shampoo is formulated to remove product buildup and is generally used only occasionally?

  1. Conditioning shampoo
  2. Balancing shampoo
  3. Clarifying shampoo Correct answer.
  4. Medicated shampoo

Explanation

Clarifying shampoo uses stronger detergents to strip oils, minerals, and styling residue. Because it can leave hair dry, it is used occasionally rather than at every shampoo.

Question 50Hair Care and Hair Services

For a client with an oily scalp and fine hair, the most suitable shampoo is one that does what?

  1. Controls oil without adding weight Correct answer.
  2. Coats the hair with silicone
  3. Delivers extra protein to the cuticle
  4. Adds heavy moisture to the cortex

Explanation

Fine hair collapses easily under heavy products, so an oily scalp needs a lightweight formula that manages sebum without weighing the hair down. Frequent shampooing with a mild formula often works best.