Barbicide is specialized disinfectant for metal tools, meets EPA standards.

Correct: Option C - On the upper lip.

In hair bleaching, the developer (hydrogen peroxide) volume determines lift strength, with 40 volume (12%) being the highest safe concentration for professional use with bleach powder to achieve maximum lightening (e.g., black to pale blonde). Volumes like 20, 25, 30, or 35 are lower, used for less lift or gentler processes. Exceeding 40 volume risks severe hair damage, making it the ceiling in standard protocols.

Hair dye (aniline tints) causes eye irritation, not safe.

Waving lotion that runs toward the scalp can be accelerated by body heat and cause overprocessing or irritation. Applying the lotion a safer distance from the scalp, typically between one half inch and one inch, reduces runoff and direct thermal acceleration at the scalp while still allowing the lotion to act on the hair shaft.

Nail growth originates in the matrix, where mitotic activity produces new cells that keratinize and push outward. The eponychium is the cuticle, the nail bed supports the nail plate, and the lunula is the visible matrix part, not the growth site. The matrix's role is analogous to the hair follicle, driving continuous nail extension, a key fact in manicure and nail health management.

Telogen is the resting phase in hair cycle (anagen: growth, catagen: transition).

Holding and moving hair prevents scalp burns when using heat tools, ensuring safety.

Egyptian henna, derived from the Lawsonia inermis plant, colors the hair by coating the hair shaft with lawsone molecules that bind to the keratin proteins on the exterior, creating a semi-permanent layer that adds reddish tones while conditioning and strengthening the hair without penetrating deeper structures. This coating mechanism provides a natural, translucent color that builds over applications, enhancing shine and thickness but allowing the underlying pigment to show through for multi-dimensional effects. Unlike penetrating methods that alter the cuticle or cortex, henna's external adhesion minimizes damage, making it suitable for sensitive scalps or damaged hair, with results lasting 4-6 weeks depending on porosity and washing frequency. Traditional use in ancient Egypt for body art and hair extended to modern cosmetology for organic alternatives, often mixed with indigo or cassia for varied shades like copper or auburn. Cosmetologists must perform strand tests due to variability in henna quality (body art vs. compound), ensuring no metallic salts are present to avoid reactions with other chemicals. This non-oxidative process requires longer development (1-3 hours) under heat, and while it coats the entire shaft, it doesn't lift color, limiting use on dark hair to subtle warmth. Benefits include UV protection and anti-fungal properties, but removal is challenging, emphasizing client education on commitment and aftercare like sulfate-free shampoos to preserve the coating.

The scientific study of hair, encompassing its growth patterns, structure, and associated disorders, is known as trichology, a specialized field that bridges dermatology and cosmetology. Trichology delves into the anatomy of the hair follicle, the cyclical growth phases - anagen (growth), catagen (transitional), and telogen (resting) - and conditions such as alopecia, dandruff, or excessive hair loss. This knowledge is invaluable for diagnosing scalp issues and tailoring hair care treatments, making it a cornerstone for professionals in hair restoration and salon services. Dermatology, while related, focuses more broadly on skin conditions including those affecting the scalp but is not specific to hair. Cosmetology involves the practical application of beauty techniques, including hair styling and coloring, but lacks the scientific depth of trichology. Biology, as a general science, covers all life forms and is too expansive to be specific to hair study alone.

Correct: Option c - Conditioner or cream rinses - These help detangle and smooth hair post-relaxing.

Pathogenic bacteria cause disease, earning them the common name 'germs' or 'microbes' in lay terms, reflecting their harmful impact on health. Antiseptics and disinfectants are agents used against them, not names, and beneficial bacteria (e.g., probiotics) are non-pathogenic. The term 'germ' historically derives from germ theory, emphasizing their role in infection, a key concept in hygiene and cosmetology sanitation.

Correct: Option B - Under development product

Cuticle nippers cut excess skin accurately and safely.

Aniline derivative tints, including para-phenylene-diamine (PPD), a key oxidative agent used in permanent hair colors for its ability to penetrate the cortex and form large color molecules with hydrogen peroxide, are also referred to as synthetic organic tints, distinguishing them from natural or inorganic alternatives due to their chemically synthesized aromatic amine structure derived from aniline. These tints offer long-lasting, vibrant shades with excellent gray coverage but require patch tests for allergies, as PPD can cause reactions in sensitive individuals. Unlike vegetable tints from plant extracts like henna for temporary hues; metallic dyes with metal salts for progressive coloring; or compound dyes mixing types; synthetic organic tints dominate modern color lines for their versatility in lifting and depositing color. Cosmetologists must follow manufacturer guidelines, considering hair porosity and previous treatments to avoid damage, while regulations like EU limits on PPD concentrations ensure safety. This classification underscores their role in professional salons for customizable, durable results that evolve with trends in fashion and personal expression.

Curl size in a permanent wave is determined primarily by the diameter of the rod used. Smaller rods produce tighter curls and larger rods produce looser waves. Product type affects processing strength and time, and density or elasticity affect response, but rod size sets the finished curl size.

Hair removal on moles causes irritation, inflammation, changes mole structure.

Hair growth cycles through three distinct phases: anagen (active growth), catagen (transitional regression), and telogen (resting phase, where hair is shed). Telogen is the final phase, preparing the follicle for a new anagen cycle. Transition and growth phases are part of anagen or overall development, not distinct stages, making telogen the correct completion of the cycle, a fundamental concept in trichology and hair care.

Disinfection kills bacteria and viruses but not spores, according to CDC.

Draping protects client's clothing and skin from chemicals, according to salon standards.

Correct: Option D - Under no circumstances.

Heated thermal irons' temperature varies with the hair texture, as coarse or thick hair requires higher heat (e.g., 350-400°F) to style effectively, while fine hair needs lower heat (e.g., 250-300°F) to avoid damage. The Marcel iron technique, hair stylist skill, or manufacturer settings are secondary factors. Texture dictates heat settings to ensure styling without compromising hair integrity, a key principle in thermal styling.

Removing a wax strip requires minimizing pain and skin trauma. Pulling in the opposite direction of hair growth ensures effective hair removal by aligning with follicle angles, while the same direction or vertical position increases resistance or incomplete removal. Quick, opposite-direction pulls are standard to reduce follicle damage, a technique honed in waxing procedures.

Good hair (poor absorption) has tight cuticles, needs more chemicals.

Apply talc powder absorbs moisture, reduces pain, increases wax adhesion.

Correct: Option a - Soften and swell - Relaxers break disulfide bonds, softening and swelling hair for straightening.

Correct: Option B - Shampoo and scalp brushing.

Correct: Option d - Microcomedone - This is the initial clogged pore that can develop into inflammatory acne.

Correct: Option A - Close to the scalp.

In cosmetology, coarse hair can be thinned closest to the scalp because it has a thicker diameter and greater density, allowing stylists to remove bulk right near the roots without causing the hair to appear too sparse or damaged. Thinning shears or razors can be applied as close as 1/2 inch from the scalp on coarse hair to effectively reduce volume and prevent a bulky appearance, while blending seamlessly due to the hair's robust structure. In contrast, fine hair requires thinning farther from the scalp (typically 1-1.5 inches away) to avoid making it look limp, stringy, or overly thin, as its delicate strands do not blend as well when cut too close. Medium hair falls in between, often thinned about 1 inch away, and damaged hair should be approached cautiously regardless of texture to prevent further breakage. This principle is taught in cosmetology training to help stylists tailor cutting techniques to different hair types, ensuring optimal results for texture management, style longevity, and client satisfaction. Factors like hair porosity, elasticity, and overall health also influence how close thinning can be done, but texture is the primary determinant.

Clarifying shampoo removes dye, hairspray, deep cleans hair.

Correct: Option D - Alopecia areata.

Porous hair absorbs well, needs less chemicals for processing.

Correct: Option B - Irritations scalp

Correct: Option c - Skin test - A patch test on the skin checks for allergic reactions or irritation.

Correct: Option B - Matrix is the correct term for the area where nail growth occurs.

Backcombing (teasing) creates volume at roots, increases fullness.

Shingling describes a graduated cutting technique where hair is cut progressively shorter toward the nape, producing a tapered or stacked effect from nape to crown. Layer cutting is a more general term for creating layers, razor cutting indicates the tool used, and club cutting is not the standard term for this graduated nape-to-crown method.

Clarifying shampoo removes oil and styling products, prepares hair for dyeing.

Correct: Option c - Inactive stage - Spores are a dormant, resistant form where bacteria are inactive.

Correct: Option D - Primary colors.

Brush-bottle is a specialized bottle for holding and applying hair dye, convenient and accurate.

Wash hands with soap and warm water removes chemicals, avoids skin irritation.

The average lifespan of hair on the human scalp is approximately 4-7 years.

The nail body also called the nail plate is the visible hard keratin that sits on the nail bed. The free edge extends beyond the fingertip, the lunula is the pale half moon at the base, and the nail root is under the skin within the matrix.

Correct: Option B - Achieves yellow color.

When performing a touch-up, color should be applied starting about 1/16 inch away from the tinted hair to avoid overlapping onto previously colored hair. Overlapping can cause uneven color and damage. Applying too far away would leave a gap, and applying directly on tinted hair causes overprocessing.

Correct: Option D - Spiral curl

Correct: Option A - Oxidation

Correct: Option A - Less heat and less pressure

<p>Why Oil Is Used:</p><p>Oil acts as an insulator and barrier.</p><p>It prevents the alkaline solution (which can be caustic) from directly touching the skin.</p><p>It reduces irritation or chemical burns caused by the galvanic current or the alkaline product.</p><p>It also helps the electrode glide smoothly on the skin’s surface.</p><p>In other words:</p><p>When the anode (positive electrode) pulls the alkaline ions from the negative electrode through the skin, the current can dry or irritate the skin.</p><p>Applying oil before the procedure protects and conditions the skin barrier from that reaction.</p>

Medium temperature (120-150°C) is safe, avoids damaging hair.

The primary structural component of hair, nails, and the outer skin layer (epidermis) is keratin, a tough, fibrous protein that provides strength and protection. Hemoglobin is a blood protein, melanin is a pigment, and calcium is a mineral, none of which form the bulk of these tissues. Keratin's cross-linked structure, rich in cysteine, enables its durability, making it essential for understanding skin and appendage biology in cosmetology.

Correct: Option C - 18 hours – 24 hours is the standard period for a skin test.

Cleansing removes dirt and oil, prepares for next steps.

Frequent strand test checks if hair has absorbed enough dye.

Excessive hydrogen peroxide swells and damages the cuticle layer, breaking down the protein structure and increasing porosity. Overuse strips natural oils and structural components, making the hair more porous and fragile. It does not make the hair resistant, nor does it decrease porosity or cause keratinization in this context.

Damaged hair breaks easily due to weak structure, cannot withstand chemicals.

Trimmer is used to sharply edge hairlines around ears and neck, creating precise lines.

Pin curls strategically positioned immediately behind or below the ridgeline—the elevated crest or wave formation in a shaping or finger wave—are known as ridge curls, a specialized technique used to reinforce and define wave patterns by adding underlying support and texture. These curls form a wave when brushed out, creating a seamless transition between ridges for a polished, sculpted effect often seen in retro hairstyles like 1930s Hollywood waves or modern editorial looks. Unlike roller curls, which use cylindrical tools for uniform volume; pivot curls, which rotate around a point for directional movement; or sculpture curls, a broader term for artistic pin curls; ridge curls specifically enhance ridge definition, allowing for stronger, more durable waves that hold against humidity or movement. In practice, cosmetologists create ridge curls by winding small sections clockwise or counterclockwise along the ridge, securing with clips, and considering hair texture—curly hair may need less winding, straight hair more tension—to achieve optimal lift and flow. This method integrates with skip waves or full finger waving, promoting volume at the sides or crown while minimizing flatness, and requires skill in sectioning and drying to prevent frizz or collapse, ultimately contributing to versatile, long-lasting styles that elevate professional services.

The nail body rests on the nail bed, a specialized skin layer beneath the nail plate that supports growth and adhesion. The matrix produces the nail, the nail root is the proximal matrix base, and nail-groove (or lateral nail fold) surrounds the nail edges. The nail bed's rich blood supply nourishes the nail, making it the correct anatomical term in nail anatomy studies.

Handwashing is cleaning, removing surface dirt and bacteria, the lowest level according to CDC.

Nitrile gloves resist chemicals, do not cause allergies, safe according to OSHA.

When hair is bleached to a red-gold tone, which typically presents as a warm, brassy shade with underlying red and yellow (gold) pigments at around level 7-8 on the hair color scale, a violet tone base is used to produce a neutralizer effect by counteracting the unwanted warmth according to the principles of the color wheel. Violet, being the complementary color to yellow/gold, effectively cancels out the gold tones, while its blue undertones help subdue the red, resulting in a more neutral, balanced ash or beige shade without over-toning or darkening the hair excessively. In contrast, orange would intensify the warmth, green primarily neutralizes red but might leave gold tones unaddressed (potentially creating a muddy effect), and gold would enhance the existing warmth. This neutralization process is vital in color correction after bleaching, involving application of a toner or semi-permanent color with violet base, considering factors like hair porosity, previous treatments, and desired end result to avoid damage and achieve even toning. Cosmetologists use this knowledge to refine bleached hair, ensuring client satisfaction with natural-looking colors that complement skin tones and maintain hair integrity through proper formulation and timing.

Primer creates strong bond between natural nails and acrylic.

The pH scale measures acidity or alkalinity, with 7 being neutral, as exemplified by pure water, where H+ and OH- ions are balanced. Values like 5, 6, 9, or 10 indicate acidic or alkaline conditions, respectively. In cosmetology, understanding pH is crucial for product formulation (e.g., shampoos, skin care) to maintain skin and hair health, with 7 serving as the baseline for neutrality.

Cuticle nippers can be reused after proper disinfection.

Correct: Option d - Frenchman - Marcel Grateau, a French hairdresser, invented Marcel waving.

Artificial hair tint removal requires a chemical that breaks down dye molecules without excessive damage. A dye solvent specifically targets synthetic colorants, while hydrogen peroxide or bleach powder with hydrogen peroxide lifts natural pigment, and a 40% H2O2 solution is too strong for safe use. The solvent's selective action preserves hair integrity, a critical consideration in color correction procedures.

Correct: Option D - The side of the head

This condition involves inflammation around the nail, often due to infection, trauma, or irritation. Onychatrophia refers to nail atrophy or wasting, Onychia to nail bed inflammation, Paronychia to the specific inflammation of the surrounding tissue (commonly caused by bacteria or fungi), and Onychoptosis to nail shedding. Paronychia is distinguished by its location and frequent association with swelling or pus, making it a key diagnosis in nail care and cosmetology.

Proper handwashing time is at least 20 seconds to remove dirt, oils, and most transient microorganisms effectively. This is a standard hygiene guideline in both cosmetology and healthcare settings to maintain sanitation. Less time may not adequately break down and rinse away contaminants.

Correct: Option B - Keep low electricity.

Massaging infected skin can spread bacteria or worsen the condition, so it is prohibited in cosmetology practices.

Correct: Option b - Acid - Aniline tint at pH 9.5 is slightly alkaline, but the question implies comparison with pure water (pH 7), and the context suggests a misunderstanding; however, based on standard definitions, it's not typically acid.

Half lift half deposit services use a mid strength developer near the classic twenty volume range that both slightly lifts and deposits. Among the choices provided twenty is not listed and twenty five volume is the closest match; five is too weak for lift, fifteen is mostly deposit, and thirty five is a high lift choice.

A substance capable of dissolving another to create a solution is defined as a solvent, a key concept in chemistry with significant applications in cosmetology. Solvents such as water, alcohol, or acetone work by interacting with solute molecules through forces like hydrogen bonding or polarity, breaking them apart to form a homogeneous mixture, as seen in nail polish removers or hair dye solutions. The solute, conversely, is the substance being dissolved, while a solution is the resulting mixture, and a binder serves to hold ingredients together rather than dissolve them. In cosmetic product development, solvents are essential for ensuring proper consistency, penetration, and efficacy, influencing the performance of creams, lotions, and other formulations.

If excessive tension is applied when wrapping hair for a permanent wave, the action of the cold wave solution—typically containing ammonium thioglycolate to break disulfide bonds—could be retarded, as the stretched hair fibers compress, limiting solution penetration and swelling, resulting in slower processing, uneven curls, or under-permed sections with potential for dryness or breakage. This occurs because tension restricts the hair's natural expansion during chemical restructuring, preventing thorough saturation and bond reformation around the rod. In contrast, proper wrapping uses even, moderate tension for smooth placement without pulling, ensuring optimal curl formation. Sources like Milady and salon forums highlight risks of too much tension causing frizz, weak waves, or hair stress, recommending relaxation techniques and end papers for control. Factors like hair texture—fine hair more susceptible—or rod size influence tension needs, with over-tension often leading to 'fishhook' ends or scalp irritation. Cosmetologists perform test curls to adjust, processing 5-25 minutes based on strength, and neutralize to stop action. This principle, from two-step perming (reduction then oxidation), underscores gentle handling for durable, bouncy results, educating clients on aftercare like protein treatments to restore strength post-service.

Correct: Option a - A filler applied to the pigmented hair - Filler helps even out porosity for better tint uptake.

Correct: Option B - Soften and slightly bleach the hair

Correct: Option d - Sulfor bonds - Disulfide bonds enable cold perming by breaking and reforming.

Hair strength and elasticity—the ability to withstand tension, stretching, and environmental stressors while returning to its original shape—are primarily traceable to the cortex, the thick middle layer of the hair shaft composed of keratin proteins arranged in coiled bundles that provide structural integrity and flexibility. The cortex, making up 80-90% of the hair's mass, contains hydrogen, salt, and disulfide bonds that enable up to 30-50% stretch when wet and resilience when dry, influenced by genetics, nutrition, and care routines. In contrast, the medulla is an inner core often absent in fine hair and contributes minimally; the cuticle is the protective outer layer for shine and barrier function but not core strength; and the follicle is the root structure for growth, not shaft properties. Damage from heat, chemicals, or UV exposure weakens cortical bonds, leading to brittleness, while treatments like protein masks reinforce them. Understanding this anatomy allows cosmetologists to tailor services, such as recommending deep conditioning for low-elasticity hair or avoiding over-processing, ensuring healthy, vibrant styles that maintain form and resist breakage over time.

Nitrocellulose is the primary ingredient that gives nail polish its film-forming properties.

Hacking is strong massage, causes pain, not relaxing.

Massaging infected, broken, or irritated skin/scalp can spread bacteria, worsen conditions, or cause pain, violating hygiene standards. A dead cell, white patch, or mangy condition (e.g., mange) are not standard contraindications; infection is the primary concern due to its contagious potential. This rule protects both client and practitioner, a cornerstone of cosmetology safety.

Blunt cutting is a one length technique. The comb supports and projects the hair while the shears cut a straight line. Fingers are used for layered or graduated work, clips only section hair, and the scissor blade does not hold the hair.

Hydrogen peroxide volume indicates its oxidizing strength, with 40 volume (12%) being a high-lift agent used for significant lightening. It produces more deposit (color change) and high lift, suitable for dark hair to blonde, but risks damage if not controlled. Low deposit options imply weaker solutions (e.g., 10 or 20 volume), making 40 volume's high-lift capacity the defining characteristic in professional hair coloring.

Nummular eczema causes red, round lesions with silver borders, usually itchy.

In cosmetology, when a hairstyle demands a high level of mobility, meaning the curls need to have significant movement, bounce, and flow away from the scalp for dynamic, voluminous looks such as cascading waves or updos with soft, swinging elements, the full-stem curl is the optimal choice. The stem in pin curls or roller sets refers to the section of hair between the scalp (base) and the first turn of the curl (circle), and its length directly dictates the curl's mobility: a no-stem curl sits flat against the scalp with minimal movement, ideal for sleek, close-to-head styles; a half-stem curl offers moderate mobility for balanced volume; while the full-stem curl, where the stem is as long as possible within the section, allows the curl to pivot freely from the base, providing maximum swing and liveliness. This technique is particularly useful in creating hairstyles that require natural-looking motion, like beach waves or formal styles with hanging tendrils, as it leverages the hair's natural elasticity and gravity for enhanced aesthetics. Cosmetologists must consider hair type—fine hair may need shorter stems to avoid limpness, while thick hair benefits from full stems for control—along with factors like face shape, occasion, and client preferences to ensure the mobility enhances rather than overwhelms the overall look. Historical styles from the 1920s flapper era to modern red-carpet appearances often incorporate full-stem curls for their versatility, and proper setting with pins or rollers, combined with products like mousse or hairspray, ensures longevity without sacrificing movement. Mastering stem variations builds foundational skills in wet and dry setting, enabling professionals to adapt to diverse textures, lengths, and trends while minimizing damage through even tension distribution.

The steel pusher is a precision tool in manicure to manage cuticles, requiring careful application to avoid nail bed damage. On a dry nail body, gentle flat pressure allows controlled cuticle movement without excessive moisture softening, which could lead to tearing. Angled use on moist nails risks injury if pressure is uneven, and moist conditions generally require different tools or techniques. This recommendation underscores the importance of technique in maintaining nail integrity during professional care.

A predisposition test for lash adhesive must be performed at least 24 hours before application to detect delayed hypersensitivity reactions. Waiting only minutes is insufficient to reveal a true allergic response.

Inherited immunity, or natural immunity, is passed genetically from parents, providing innate resistance (e.g., to certain diseases) without exposure. Acquired immunity develops post-exposure, vaccination involves artificial immunization, and susceptible indicates lack of immunity. Natural immunity's basis in genetic factors like antibodies or phagocytes underscores its congenital nature, relevant in health-related cosmetology contexts.

Thinning with scissors is commonly called slithering. This technique uses scissors or thinning shears at a shallow angle to remove bulk and create softer lines. Clipper over comb is a clipper technique, razor cutting uses a straight razor for texture and edge, and layer cutting builds length differences rather than specifically thinning.

Correct: Option D - 10 major color changes.

Dermis contains blood vessels, nerves, sweat glands.

For virgin sodium hydroxide relaxers apply to the most resistant mid shaft first keeping product off the scalp and porous ends initially. Heat at the scalp speeds processing and ends absorb fastest, so starting about one half inch away prevents over processing and breakage; scalp and ends are addressed last to even out the result.

Combining coloring and perming involves chemical processes (oxidation for color, reduction for perms) that can damage hair if simultaneous. Tinting first then perming, or applying tint a week later, risks uneven results due to altered cuticle states. The safest approach is perming first, waiting at least 3 days, then tinting to allow hair recovery and ensure chemical compatibility, a standard protocol in cosmetology.

Soft wax efficiently removes hair over broad regions such as legs arms and back. Tweezing and electric tweezers are slow and suited for small localized areas. Bleaching agents only lighten hair color and do not remove it.

Metallic dye causes unwanted chemical reactions, making other services difficult.

Correct: Option C - Use the piggy back method of wrapping.