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NH Cosmetology practice questions

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Question 1Scientific Concepts and Hair Care

Which layer of the hair shaft contains the melanin that determines natural hair color?

  1. Cuticle
  2. Inner root sheath
  3. Cortex Correct answer.
  4. Medulla

Explanation

The cortex is the thick middle layer of the hair shaft and holds the melanin granules that give hair its natural color. Melanin is deposited in the cortex during keratinization, so any color change that alters melanin must affect this layer.

Question 2Scientific Concepts and Hair Care

A client's hair is described as having low porosity. Which behavior should the stylist expect during a chemical service?

  1. The hair holds curl poorly because the cortex is unstable
  2. The hair absorbs water quickly but loses moisture just as fast
  3. The cuticle resists wetting and products absorb slowly Correct answer.
  4. The cuticle lifts easily and products absorb rapidly

Explanation

Low-porosity hair has a tightly closed cuticle that sheds water and resists penetration of moisture and chemicals. Products sit on the surface, so processing may require heat, longer development time, or a pre-softening step.

Question 3Scientific Concepts and Hair Care

Which bond in the hair is broken by a thio relaxer and then reformed in the new shape during rinsing and neutralizing?

  1. Disulfide bond Correct answer.
  2. Hydrogen bond
  3. Peptide bond
  4. Salt bond

Explanation

Thio relaxers reduce disulfide bonds between cysteine units in the cortex, allowing the hair to be reshaped. The neutralizing step oxidizes those bonds back into their new positions, locking in the straightened form.

Question 4Scientific Concepts and Hair Care

Which statement correctly describes the growth phase during which a hair is most vulnerable to damage from chemical services?

  1. Telogen is the active growth phase when pigment is produced
  2. Anagen is the active growth phase and the hair is fully formed and attached Correct answer.
  3. Catagen is the resting phase when the follicle is dormant
  4. Anagen is the shedding phase when the hair detaches from the papilla

Explanation

Anagen is the active growth phase, when the follicle is producing a fully keratinized, attached hair shaft. Catagen is a short transitional phase and telogen is the resting phase that ends in shedding.

Question 5Scientific Concepts and Hair Care

A client with a round face shape wants a style that visually lengthens the face. Which design choice best supports that goal?

  1. A blunt fringe straight across the forehead
  2. A center part with heavy side volume
  3. Volume at the sides with a wide silhouette
  4. Height at the crown with a narrow silhouette Correct answer.

Explanation

Adding height at the crown draws the eye vertically and creates the illusion of a longer, narrower face. Width at the sides does the opposite by emphasizing the horizontal dimension.

Question 6Scientific Concepts and Hair Care

Which of the following best describes the function of the arrector pili muscle?

  1. It contracts to make the hair stand up and creates goose bumps Correct answer.
  2. It supplies blood to the hair bulb
  3. It produces new cells that keratinize into the hair shaft
  4. It secretes sebum onto the hair and scalp

Explanation

The arrector pili is a tiny smooth muscle attached to the follicle that contracts in response to cold or emotion, lifting the hair and dimpling the skin. It has no role in sebum production, cell division, or blood supply.

Question 7Scientific Concepts and Hair Care

A stylist is selecting a shampoo for a client with an oily scalp and fine hair. Which product characteristic is most appropriate?

  1. A color-depositing shampoo with high conditioning
  2. A heavy cream shampoo with rich emollients
  3. A moisturizing shampoo with added oils
  4. A clarifying or balancing formula with low conditioning agents Correct answer.

Explanation

Fine hair with an oily scalp benefits from a light, clarifying or balancing formula that removes excess sebum without weighing hair down. Heavy emollients and oils add weight and can make fine hair appear limp.

Question 8Scientific Concepts and Hair Care

Which factor most directly determines the strength of the hydrogen peroxide developer used in a color service?

  1. The volume of oxygen released relative to its concentration Correct answer.
  2. The amount of ammonia in the color formula
  3. The temperature of the client's scalp
  4. The pH of the final mixture only

Explanation

Developer strength is expressed by volume, which reflects the concentration of hydrogen peroxide and the oxygen it releases. Higher volumes lift more melanin and deposit more color, while ammonia and pH affect processing but do not define developer strength.

Question 9Scientific Concepts and Hair Care

During a patch test for a color product, which observation indicates a positive reaction requiring the service to be postponed?

  1. Redness, swelling, or itching at the test site Correct answer.
  2. Mild dryness with no color change
  3. A slight cooling sensation that fades quickly
  4. Temporary staining of the skin

Explanation

A positive patch test shows signs of allergic reaction such as redness, swelling, itching, or blistering at the test site. Any such reaction means the product should not be applied and the client should be referred for medical advice.

Question 10Scientific Concepts and Hair Care

Which statement accurately describes the relationship between pH and the hair cuticle?

  1. pH has no measurable effect on cuticle scales
  2. Neutral pH always permanently straightens the hair
  3. Alkaline products swell and lift the cuticle, while acidic products help it lie flat Correct answer.
  4. Acidic products swell the cuticle, while alkaline products close it

Explanation

Alkaline solutions cause the cuticle to swell and lift, which allows chemicals to penetrate but also increases porosity. Acidic products contract the cuticle and smooth the surface, which is why acid rinses add shine.

Question 11Scientific Concepts and Hair Care

A client reports that her scalp is dry, flaky, and itchy but shows no redness or broken skin. Which action is within the cosmetologist's scope?

  1. Apply a strong exfoliating acid to remove the flakes
  2. Recommend a mild moisturizing scalp treatment and refer persistent cases to a physician Correct answer.
  3. Diagnose seborrheic dermatitis and prescribe a medicated shampoo
  4. Recommend an oral antifungal supplement

Explanation

Cosmetologists may recommend gentle moisturizing scalp treatments for simple dryness but cannot diagnose skin disorders or prescribe medication. Persistent or worsening conditions must be referred to a physician.

Question 12Scientific Concepts and Hair Care

Which type of hair is most resistant to chemical processing because of its tightly packed, overlapping cuticle scales?

  1. Coarse, low-porosity hair Correct answer.
  2. Fine, high-porosity hair
  3. Grey hair with a loose cuticle
  4. Medium-textured hair with normal porosity

Explanation

Coarse hair has a wide diameter and, when porosity is low, tightly overlapping cuticle scales that resist penetration. Such hair usually needs stronger products, longer processing, or pre-softening before chemical services.

Question 13Scientific Concepts and Hair Care

Which tool is designed to remove bulk length quickly while leaving a blunt or uniform perimeter?

  1. Shears Correct answer.
  2. Razor
  3. Clippers with a guard
  4. Thinning shears

Explanation

Shears cut hair cleanly at the perimeter and are the standard tool for establishing length and blunt lines. Razors and thinning shears create texture and softness rather than a solid perimeter.

Question 14Scientific Concepts and Hair Care

In a haircut, the elevation at which hair is held determines which outcome?

  1. The porosity of the ends
  2. The color deposit on the mid-lengths
  3. The direction of the client's hair growth pattern
  4. The degree of graduation or layering in the shape Correct answer.

Explanation

Elevation is the angle at which hair is held away from the head during cutting, and it controls how much length is removed and how graduated the shape becomes. Low elevation builds weight, while high elevation creates layers.

Question 15Scientific Concepts and Hair Care

Which statement best explains why a wet haircut may appear different once the hair dries?

  1. Wet hair is always shorter because water contracts the cortex
  2. Wet hair has no elasticity, so it cannot be cut accurately
  3. Wet hair stretches and clumps, so the dry result shows the true length and texture Correct answer.
  4. Dry hair is heavier because it retains moisture

Explanation

Water breaks hydrogen bonds and makes hair more elastic, so wet hair stretches and clumps together, hiding detail. As it dries, bonds reform and the hair returns to its natural length and texture, revealing the actual result.

Question 16Scientific Concepts and Hair Care

Which styling product is most suitable for adding firm hold and shine to a finished updo?

  1. Setting lotion
  2. Light leave-in conditioner
  3. Aerosol hairspray Correct answer.
  4. Pomade with heavy wax

Explanation

Aerosol hairspray provides a fine, firm film that holds a finished style and adds shine without weighing it down. It is applied as a final step to lock the shape in place.

Question 17Scientific Concepts and Hair Care

Which sequence correctly describes a basic shampoo and conditioning service?

  1. Analyze scalp, apply conditioner, shampoo, rinse
  2. Apply conditioner, shampoo, rinse, towel dry
  3. Shampoo, towel dry, apply conditioner, comb, leave in
  4. Analyze hair and scalp, shampoo, rinse, apply conditioner, rinse, towel dry Correct answer.

Explanation

The service begins with analysis to select appropriate products, followed by shampooing, rinsing, conditioning, and a final rinse before towel drying. Conditioner is applied after shampoo so it can smooth the cuticle left slightly raised by cleansing.

Question 18Scientific Concepts and Hair Care

Which result occurs when a relaxer is left on the hair beyond the recommended processing time?

  1. The curl pattern returns permanently
  2. Excessive bond reduction can cause breakage and scalp irritation Correct answer.
  3. The hair becomes more resistant and stronger
  4. The cuticle becomes more compact and shiny

Explanation

Over-processing continues reducing disulfide bonds and can damage the cortex, causing breakage, loss of elasticity, and chemical burns on the scalp. Processing time must be monitored and not extended beyond the manufacturer's instructions.

Question 19Scientific Concepts and Hair Care

Which term describes the natural direction in which hair grows from the scalp?

  1. Growth pattern Correct answer.
  2. Projection
  3. Distribution
  4. Elevation

Explanation

Growth pattern refers to the direction the hair naturally flows from the follicle, such as a cowlick or widow's peak. Elevation, distribution, and projection describe how hair is held during cutting, not its natural direction.

Question 20Scientific Concepts and Hair Care

Which characteristic of the hair shaft explains why chemical straightening is possible?

  1. The medulla contains keratin that can be dissolved
  2. The cuticle contains pigment that can be bleached
  3. The follicle contains nerves that respond to chemicals
  4. The cortex contains disulfide bonds that can be rearranged Correct answer.

Explanation

Chemical straightening depends on reducing and rearranging the disulfide bonds in the cortex, which hold the hair's shape. Once rearranged and oxidized, the hair retains the new configuration until new growth appears.

Question 21Scientific Concepts and Hair Care

A client with very fine hair wants a voluminous blowout. Which technique best supports that result?

  1. Applying a heavy pomade to the roots before drying
  2. Using a low-heat diffuser with no tension
  3. Blow-drying downward with a paddle brush
  4. Lifting hair at the root with a round brush and directing heat to the base Correct answer.

Explanation

Volume comes from lifting the hair at the root and setting it with heat so that the base stands away from the scalp. Heavy products or downward tension flatten the root and reduce lift.

Question 22Scientific Concepts and Hair Care

Which statement about the pH scale is correct for hair care products?

  1. The pH scale ranges from 1 to 10 with 5 as neutral
  2. A pH of 7 is alkaline, below 7 is neutral, and above 7 is acidic
  3. A pH of 0 is neutral and higher numbers are more acidic
  4. A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline Correct answer.

Explanation

The pH scale runs from 0 to 14, with 7 as neutral; values below 7 are acidic and above 7 are alkaline. Hair and scalp prefer slightly acidic products, which help keep the cuticle smooth.

Question 23Scientific Concepts and Hair Care

Which explanation best accounts for why hair becomes more porous after repeated bleaching?

  1. The cortex becomes denser and repels water
  2. The cuticle is progressively lifted and lost, exposing the cortex Correct answer.
  3. The medulla thickens and blocks moisture
  4. Melanin is converted into new cuticle scales

Explanation

Bleach raises the cuticle and oxidizes melanin, and repeated cycles strip away cuticle scales. With less protective cuticle, the cortex is exposed and hair absorbs and loses moisture more readily.

Question 24Scientific Concepts and Hair Care

Which massage movement is performed with light, gliding strokes over the scalp during a shampoo service?

  1. Petrissage
  2. Effleurage Correct answer.
  3. Vibration
  4. Tapotement

Explanation

Effleurage is a light, continuous gliding stroke used to begin and end a scalp massage. Tapotement is a percussive movement, petrissage involves kneading, and vibration is a rapid shaking motion.

Question 25Scientific Concepts and Hair Care

A client with a history of scalp psoriasis requests a chemical relaxer. What is the most appropriate action?

  1. Do not proceed and refer the client to a physician before any chemical service Correct answer.
  2. Perform the service only on the scalp area
  3. Apply a protective oil and continue with the service
  4. Proceed with a stronger relaxer to shorten contact time

Explanation

Psoriasis involves inflamed, broken skin that a strong alkaline relaxer could severely irritate or burn. Cosmetologists should not perform chemical services over compromised scalp tissue and should refer the client for medical clearance.

Question 26Scientific Concepts and Hair Care

Which layer of the hair shaft contains the melanin that gives hair its natural color?

  1. The inner root sheath
  2. The medulla
  3. The cuticle
  4. The cortex Correct answer.

Explanation

The cortex is the thick middle layer of the hair shaft and holds the melanin pigment granules that determine natural color. Chemical and physical services that change color or shape act primarily on this layer.

Question 27Scientific Concepts and Hair Care

A client's hair is described as having a low porosity cuticle. Which behavior should the stylist expect during a conditioning treatment?

  1. The hair resists absorbing moisture and products Correct answer.
  2. The hair releases color pigment spontaneously
  3. The hair absorbs moisture quickly and dries rapidly
  4. The hair loses protein without any chemical service

Explanation

Low porosity means the cuticle scales lie tightly closed, so water and conditioning molecules penetrate slowly and products may sit on the surface. Heat and longer processing time are often used to help open the cuticle.

Question 28Scientific Concepts and Hair Care

Which term describes the study of the functions and activities of the body's cells, tissues, and organs?

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

Explanation

Physiology is the study of how living structures function, including the processes that keep cells, tissues, and organs working. Anatomy instead focuses on the structure and form of body parts.

Question 29Scientific Concepts and Hair Care

A stylist is examining a client's scalp and notes a small, raised, pigmented spot with irregular borders that has changed size over the past few months. What is the appropriate action?

  1. Refer the client to a physician for evaluation Correct answer.
  2. Exfoliate the area and continue the service
  3. Cover the spot with styling product during the service
  4. Apply a medicated scalp treatment and recheck in a week

Explanation

A pigmented lesion with irregular borders that is changing in size is a warning sign that requires medical evaluation. Cosmetologists are limited to recognition and referral, not diagnosis or treatment of such conditions.

Question 30Scientific Concepts and Hair Care

Which statement correctly describes the anagen phase of the hair growth cycle?

  1. It is the transition phase, lasting only a few weeks
  2. It is the resting phase, when the hair is shed
  3. It is the phase in which the follicle produces no pigment
  4. It is the active growth phase, lasting from two to six years Correct answer.

Explanation

Anagen is the active growth phase during which new cells form and the hair lengthens; it can last several years and determines how long a hair can grow. Catagen is the short transition phase and telogen is the resting phase.

Question 31Scientific Concepts and Hair Care

Which structure anchors the hair into the skin and supplies it with nutrients through a blood vessel network?

  1. The hair bulb
  2. The arrector pili muscle
  3. The hair follicle Correct answer.
  4. The sebaceous gland

Explanation

The hair follicle is the tube-like depression in the skin from which the hair grows, and the papilla at its base contains blood vessels that nourish the growing hair. The bulb surrounds the papilla and is part of the follicle's base.

Question 32Scientific Concepts and Hair Care

Which characteristic of terminal hair distinguishes it from vellus hair?

  1. It is longer, thicker, and pigmented Correct answer.
  2. It grows only on the palms
  3. It lacks a medulla in all cases
  4. It is short, fine, and unpigmented

Explanation

Terminal hair is the long, coarse, pigmented hair found on the scalp and, after puberty, on other body areas. Vellus hair is short, fine, and lightly pigmented.

Question 33Scientific Concepts and Hair Care

A client with a round face shape asks for a style that creates the illusion of length. Which design choice supports that goal?

  1. Cutting a heavy fringe straight across
  2. Adding height at the crown with volume Correct answer.
  3. Adding width at the cheekbones
  4. Building fullness at the jawline

Explanation

Vertical volume at the crown draws the eye upward and makes a round face appear longer and narrower. Adding width at the cheeks or jaw emphasizes the horizontal dimension.

Question 34Scientific Concepts and Hair Care

Which color principle explains why yellow cancels unwanted purple tones in pre-lightened blonde hair?

  1. Yellow and purple are both primary colors
  2. Yellow and purple are analogous colors
  3. Yellow and purple share the same level of intensity
  4. Yellow and purple are complementary colors on the color wheel Correct answer.

Explanation

Complementary colors sit opposite each other on the color wheel and neutralize one another when combined. Because purple is opposite yellow, a yellow-based toner reduces unwanted purple or violet tones.

Question 35Scientific Concepts and Hair Care

Which term describes the lightness or darkness of a hair color?

  1. Level Correct answer.
  2. Base
  3. Intensity
  4. Tone

Explanation

Level refers to the degree of lightness or darkness of a color, usually numbered from black to lightest blonde. Tone describes warmth or coolness, and intensity describes the strength of the hue.

Question 36Scientific Concepts and Hair Care

During a hair analysis, a stylist tests whether the hair stretches and returns to its original length. Which property is being evaluated?

  1. Porosity
  2. Elasticity Correct answer.
  3. Texture
  4. Density

Explanation

Elasticity is the hair's ability to stretch and return to its normal length without breaking. Good elasticity indicates strong internal bonds; poor elasticity warns that chemical services may cause breakage.

Question 37Scientific Concepts and Hair Care

Which function does sebum perform for the hair and scalp?

  1. It produces melanin for the hair shaft
  2. It lubricates the hair and helps retain moisture Correct answer.
  3. It generates new cells in the follicle
  4. It transmits sensory information to the brain

Explanation

Sebum is an oily substance secreted by the sebaceous glands that coats the hair and scalp, providing lubrication and helping to slow moisture loss. It does not produce pigment or new cells.

Question 38Scientific Concepts and Hair Care

Why is a patch test recommended before applying a permanent hair color product to a client for the first time?

  1. To check whether the color will lift two levels
  2. To measure the hair's porosity
  3. To determine the exact processing time needed
  4. To identify a potential allergic sensitivity to the product Correct answer.

Explanation

A patch test exposes a small area of skin to the product so that an allergic reaction can be identified before a full application. It does not predict color results or processing time.

Question 39Scientific Concepts and Hair Care

A client with highly porous, over-processed hair requests a single-process color to go lighter. Which approach is safest?

  1. Choose a gentle formula and strand test before the full application Correct answer.
  2. Apply the lightest formula available for maximum lift
  3. Apply the color over the entire length for an even result
  4. Skip the strand test because the color is single-process

Explanation

Highly porous hair absorbs and releases pigment unevenly and is prone to breakage, so a gentle formula plus a strand test predicts the outcome before committing. Testing protects against unpredictable lift and damage.

Question 40Scientific Concepts and Hair Care

Which statement describes the relationship between the medulla and fine hair?

  1. Fine hair always has a wide, continuous medulla
  2. The medulla is thicker in fine hair than in coarse hair
  3. Fine hair may lack a medulla entirely Correct answer.
  4. The medulla determines the hair's natural color

Explanation

The medulla is the innermost layer of the hair shaft and is often absent or fragmented, particularly in fine and light-colored hair. Its presence is not required for the hair to be healthy.

Question 41Scientific Concepts and Hair Care

A stylist wants to increase volume during a thermal blow-dry on fine hair. Which technique best supports that result?

  1. Using a low setting with no tension
  2. Directing the hair flat against the scalp
  3. Applying heavy pomade to the roots before drying
  4. Lifting the hair at the root with a round brush Correct answer.

Explanation

Lifting the hair at the root with a round brush creates tension and shape that lift the hair away from the scalp, producing volume. Heavy product or flat drying weighs hair down.

Question 42Scientific Concepts and Hair Care

Which ingredient in a shampoo is primarily responsible for removing oil and debris from the hair and scalp?

  1. Preservative
  2. Surfactant Correct answer.
  3. Silicone
  4. Humectant

Explanation

Surfactants lower surface tension so that water can lift and rinse away oil, dirt, and product residue. Humectants attract moisture, silicones add smoothness, and preservatives prevent microbial growth.

Question 43Scientific Concepts and Hair Care

A client's hair has been lightened several times and now feels rough and tangles easily. Which explanation best accounts for this change?

  1. The cuticle has been lifted and worn away, exposing the cortex Correct answer.
  2. The medulla has thickened and hardened
  3. The hair has entered the telogen phase
  4. The sebaceous glands have stopped producing sebum

Explanation

Repeated lightening raises and eventually removes cuticle scales, leaving the cortex exposed and the surface rough. This increases porosity, causing tangling, dryness, and loss of shine.

Question 44Scientific Concepts and Hair Care

Which condition is a contagious fungal infection of the scalp that must be referred to a physician?

  1. Psoriasis
  2. Alopecia areata
  3. Seborrheic dermatitis
  4. Tinea capitis Correct answer.

Explanation

Tinea capitis, or ringworm of the scalp, is a contagious fungal infection that requires medical treatment and must not be serviced in the salon. The other conditions listed are inflammatory or autoimmune and are not contagious fungal infections.

Question 45Scientific Concepts and Hair Care

Which massage movement consists of light, gliding strokes used to begin and end a scalp massage?

  1. Effleurage Correct answer.
  2. Petrissage
  3. Tapotement
  4. Friction

Explanation

Effleurage uses light, continuous gliding strokes and is typically used to open and close a massage. Petrissage involves kneading, tapotement uses tapping, and friction uses circular pressure.

Question 46Scientific Concepts and Hair Care

A client with a known allergy to a color product's developer experiences itching and redness during a service. What should the stylist do first?

  1. Cover the area with a barrier cream and proceed
  2. Stop the service and remove the product immediately Correct answer.
  3. Continue and apply a soothing conditioner over the color
  4. Increase processing time to finish the service

Explanation

Signs of an allergic reaction require immediate discontinuation and thorough removal of the product to limit exposure. The stylist should then advise the client to seek medical attention if symptoms persist or worsen.

Question 47Scientific Concepts and Hair Care

Which statement correctly describes the direction of hair growth known as the hair stream?

  1. Hair streams are created only by cutting the hair against the grain
  2. Hair streams flow from the scalp in a natural direction, forming patterns such as cowlicks Correct answer.
  3. Hair streams determine the hair's natural color level
  4. Hair streams are the same as the hair's porosity

Explanation

A hair stream is the natural direction in which hair flows from the scalp, and it can create visible patterns such as cowlicks or whorls. Stylists work with the stream to avoid unruly sections.

Question 48Scientific Concepts and Hair Care

Which property of the hair shaft allows it to be reshaped during a wet set?

  1. The cuticle grows new scales after drying
  2. The cortex permanently fuses when wet
  3. Hydrogen bonds can be rearranged when the hair is wet and reset when it dries Correct answer.
  4. Melanin granules dissolve in water

Explanation

Water breaks temporary hydrogen bonds, allowing the hair to be molded around a roller; as the hair dries, new bonds form and hold the shape. This is why a wet set lasts until the hair is rewetted.

Question 49Scientific Concepts and Hair Care

Which factor most affects how much a relaxer will straighten a client's hair?

  1. The hair's texture, porosity, and the strength of the relaxer Correct answer.
  2. The brand of shampoo used at home
  3. The length of the client's fingernails
  4. The color of the client's eyes

Explanation

Relaxer results depend on the hair's natural texture and porosity, which govern how quickly the product penetrates, along with the strength of the relaxer. These factors determine processing time and outcome.

Question 50Scientific Concepts and Hair Care

Which statement about the pH scale is accurate for hair care products?

  1. A pH of 14 is neutral for hair
  2. A pH of 7 is acidic and opens the cuticle
  3. A pH below 7 is acidic and tends to close the cuticle Correct answer.
  4. A pH above 7 is acidic and smooths the cuticle

Explanation

On the pH scale, values below 7 are acidic and values above 7 are alkaline. Acidic products help contract the cuticle and add shine, while alkaline products swell and open it.