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TN Cosmetology study materials
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TN Cosmetology practice questions

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Question 1Infection Control, Sanitation, and Safety Practices

Which statement best defines disinfection?

  1. Destroying every microorganism, including spores
  2. Killing most pathogens on a surface Correct answer.
  3. Rinsing an implement under running water
  4. Brushing soil off a tool with soap

Explanation

Disinfection uses an EPA-registered product to destroy most pathogenic organisms on a nonporous surface, but it does not necessarily kill bacterial spores. Cleaning with soap and water is a separate first step, and destroying every organism including spores is sterilization.

Question 2Infection Control, Sanitation, and Safety Practices

When washing the hands with soap and warm water, how long should you lather and scrub?

  1. At least 20 seconds Correct answer.
  2. About 3 seconds
  3. Until the lather disappears
  4. At least 5 minutes

Explanation

Health agencies recommend lathering with soap and warm water for at least 20 seconds, covering palms, backs of hands, between the fingers and under the nails. Shorter times do not give the soap enough contact time to remove transient pathogens.

Question 3Infection Control, Sanitation, and Safety Practices

Which federal agency reviews and registers the disinfectants sold for salon use?

  1. EPA Correct answer.
  2. FDA
  3. CDC
  4. OSHA

Explanation

The EPA registers disinfectants and approves the efficacy claims printed on their labels, so a salon product should carry an EPA registration number. OSHA enforces workplace safety rules and the FDA regulates cosmetics and drugs rather than disinfectant registration.

Question 4Infection Control, Sanitation, and Safety Practices

Which of these implements is porous and therefore should not be reused on another client after disinfection?

  1. A stainless steel cuticle pusher
  2. A wooden emery board Correct answer.
  3. A glass tint bowl
  4. A plastic tail comb

Explanation

Porous materials such as wood, paper, foam and unsealed plastic absorb liquids and harbor microorganisms, so they cannot be reliably disinfected and must be discarded after a single use. Nonporous materials like metal, glass and hard plastic can be cleaned and disinfected.

Question 5Infection Control, Sanitation, and Safety Practices

Which of the following is a bloodborne pathogen?

  1. The mite that causes scabies
  2. Hepatitis B virus Correct answer.
  3. The bacterium that causes tuberculosis
  4. The fungus that causes ringworm

Explanation

Hepatitis B is a virus transmitted through blood and other body fluids, so it is a bloodborne pathogen covered by OSHA's Bloodborne Pathogens Standard. Ringworm is fungal, scabies is caused by a mite, and tuberculosis is spread through the air.

Question 6Infection Control, Sanitation, and Safety Practices

An autoclave destroys microorganisms by using:

  1. Ultraviolet light in a closed cabinet
  2. Dry heat at about 120 degrees Fahrenheit
  3. A hospital-grade chemical soak
  4. Steam under pressure at about 250 degrees Fahrenheit Correct answer.

Explanation

An autoclave is a sterilization unit that uses steam under pressure, typically about 250 degrees Fahrenheit at 15 psi for 15 to 20 minutes, to destroy all microbial life including spores. Chemical soaks and ultraviolet cabinets do not achieve sterilization in a salon setting.

Question 7Infection Control, Sanitation, and Safety Practices

Employers must keep a Safety Data Sheet on file for each chemical in the salon because of regulations from:

  1. The FDA
  2. The local fire marshal
  3. OSHA Correct answer.
  4. The EPA

Explanation

OSHA's Hazard Communication Standard requires employers to keep a Safety Data Sheet for every hazardous chemical in the workplace and to make it accessible to employees. The sheets summarize hazards, safe handling, storage and first-aid measures.

Question 8Infection Control, Sanitation, and Safety Practices

What must be done to a metal implement immediately before it is placed in disinfectant?

  1. Washed and dried with soap and water Correct answer.
  2. Sprayed with disinfectant first
  3. Heated briefly in a microwave to loosen any debris
  4. Wiped once with a paper towel

Explanation

Visible debris and oils shield microorganisms and can inactivate disinfectants, so implements must be washed with soap and water and dried before immersion. Skipping the cleaning step is one of the most common causes of disinfection failure.

Question 9Infection Control, Sanitation, and Safety Practices

A steel implement contacts a client's blood during a service. What is the correct processing for that implement?

  1. Rinsed under running water and left to air dry
  2. Cleaned, then sterilized or tuberculocidal-disinfected Correct answer.
  3. Wiped with a quaternary ammonium wipe and put away in a drawer
  4. Soaked for two minutes in a low-level disinfectant solution

Explanation

An implement that contacts blood is treated as contaminated with bloodborne pathogens and must be cleaned, then sterilized or immersed in an EPA-registered hospital-grade tuberculocidal disinfectant for the full label contact time. Routine low-level sanitation is not adequate after a blood exposure.

Question 10Infection Control, Sanitation, and Safety Practices

Quaternary ammonium compounds are classified as:

  1. High-level sterilants that destroy spores
  2. Antiseptics for use on broken skin
  3. Low-level disinfectants Correct answer.
  4. Fumigants for the whole salon

Explanation

Quaternary ammonium compounds are low-level disinfectants effective against many bacteria and some viruses, but they are not tuberculocidal and do not destroy spores. They are widely used for general surfaces and for implements that have not contacted blood.

Question 11Infection Control, Sanitation, and Safety Practices

For a blood spill on a hard, nonporous floor, which bleach dilution is the standard strength?

  1. One part bleach to one part water
  2. One part bleach to nine parts water Correct answer.
  3. One part bleach to three parts water
  4. Full-strength bleach straight from the container

Explanation

A 1:10 dilution, one part household bleach to nine parts water, is the standard strength for disinfecting blood and body-fluid spills on hard surfaces. Stronger concentrations do not improve the kill and increase fumes, skin irritation and damage to surfaces.

Question 12Infection Control, Sanitation, and Safety Practices

Sterilization is different from disinfection because sterilization:

  1. Requires less time and costs much less money
  2. Is required for every salon tool
  3. Destroys all microbial life and spores Correct answer.
  4. Is performed only on the client's skin

Explanation

Sterilization destroys all forms of microbial life, including the highly resistant bacterial spores that survive ordinary disinfection. In salons it is achieved with an autoclave or a registered high-level sterilant on items that contact blood or break the skin.

Question 13Infection Control, Sanitation, and Safety Practices

A disinfectant label instructs a 10-minute immersion, but a cosmetologist soaks the implements for only 4 minutes. Which statement is correct?

  1. Adding extra disinfectant makes a shorter soak acceptable
  2. The full label contact time is required Correct answer.
  3. Four minutes is long enough for metal tools
  4. The tools are sterile because they were submerged

Explanation

Disinfectants are registered with a specific dilution and contact time, and the product is only proven to work when items stay submerged for the full time stated on the label. Cutting the soak short leaves pathogens alive on the implement.

Question 14Infection Control, Sanitation, and Safety Practices

A client has intense itching with tiny burrows between the fingers. This most likely indicates:

  1. Pediculosis
  2. Folliculitis
  3. Scabies Correct answer.
  4. Tinea pedis

Explanation

Scabies is caused by a microscopic mite that burrows into the skin, producing intense itching and thin linear tracks, often in the webs of the fingers. It is contagious through prolonged skin contact and the client should be referred for medical treatment.

Question 15Infection Control, Sanitation, and Safety Practices

MRSA is best described as:

  1. A virus that attacks the liver
  2. A mite that burrows under the skin
  3. A fungus that thickens and discolors the nail plate
  4. A staph bacterium resistant to antibiotics Correct answer.

Explanation

MRSA stands for methicillin-resistant Staphylococcus aureus, a bacterium that has developed resistance to many common antibiotics and spreads by skin contact or contaminated tools and surfaces. It is not a virus, fungus or parasite, and it can be life-threatening in compromised clients.

Question 16Infection Control, Sanitation, and Safety Practices

Following standard precautions in the salon means:

  1. Disinfecting all tools once at the end of each workday
  2. Wearing gloves only when a client appears ill
  3. Asking each client to sign a health release
  4. Treating all blood and body fluids as infectious Correct answer.

Explanation

Standard precautions require treating all blood, body fluids and potentially infectious materials as if they were infected, regardless of how healthy the client appears. Barriers such as gloves and proper hand washing are used with every client, and tools are processed after each service.

Question 17Infection Control, Sanitation, and Safety Practices

A disinfectant solution in the salon has become cloudy and contains visible debris. What is the correct action?

  1. Top it off with fresh concentrate
  2. Add hot water to stretch the solution
  3. Strain it through a fine filter
  4. Discard it and mix a fresh solution Correct answer.

Explanation

Cloudy or dirty solution carries organic soil and may have lost potency, so it must be discarded, the container cleaned and a fresh solution mixed at the label dilution. Solutions are dated when mixed so old product is not reused.

Question 18Infection Control, Sanitation, and Safety Practices

Which statement about an ultraviolet light cabinet for nail implements is accurate?

  1. It leaves a residue that must be rinsed off
  2. It is the only way to destroy bacterial spores
  3. It is a sterilizer approved by the EPA
  4. It sanitizes at best; it does not sterilize Correct answer.

Explanation

Ultraviolet cabinets are not approved sterilizers and provide only a low level of sanitizing, since the light cannot reach spores or debris hidden in tool joints and hinges. Implements that need disinfection or sterilization must be processed with a registered chemical or an autoclave.

Question 19Infection Control, Sanitation, and Safety Practices

If a client's blood contacts a cut on your hand, what should you do first?

  1. Seal the cut with nail adhesive
  2. Soak the hand in disinfectant
  3. Wash it with soap and water Correct answer.
  4. Finish the service and then report it

Explanation

After any blood exposure, the first step is to wash the affected area thoroughly with soap and water, then report the incident and follow the salon's exposure-control plan, which may include medical evaluation. Disinfectants are formulated for surfaces and tools, not for living tissue.

Question 20Infection Control, Sanitation, and Safety Practices

Why should a disinfectant never be mixed with another chemical product?

  1. It automatically voids the salon's liability insurance
  2. It may release toxic gas or reduce efficacy Correct answer.
  3. It causes implements to corrode instantly
  4. It makes the solution too costly to use

Explanation

Mixing incompatible products, such as bleach with ammonia or an acid, can release toxic gases and can also inactivate the disinfectant so it no longer works at label strength. Products should be used exactly as directed and never combined.

Question 21Infection Control, Sanitation, and Safety Practices

Which of these will destroy bacterial spores on a metal implement?

  1. A hospital-grade quaternary ammonium soak
  2. A five-minute bleach soak
  3. A 70 percent alcohol wipe
  4. Steam sterilization in an autoclave Correct answer.

Explanation

Bacterial spores are the most resistant form of microbial life and survive ordinary disinfectants, so destroying them requires sterilization such as steam under pressure in an autoclave. Tuberculocidal and low-level disinfectants kill many pathogens but not necessarily spores.

Question 22Infection Control, Sanitation, and Safety Practices

Which device protects against electric shock when a tool comes into contact with water?

  1. A surge-protector power strip with a reset button
  2. A 15-amp extension cord
  3. A three-prong adapter plug
  4. A ground-fault circuit interrupter Correct answer.

Explanation

A ground-fault circuit interrupter monitors current and shuts off power within milliseconds if electricity begins to leak to ground, protecting users from shock near water. It is required in wet locations such as shampoo areas and pedicure stations.

Question 23Infection Control, Sanitation, and Safety Practices

A stylist develops numbness and tingling in the wrist from repeated cutting motions. What is the best preventive step?

  1. Wear a tight wristband during every service
  2. Work through the pain to build wrist strength
  3. Switch to a heavier pair of shears
  4. Adjust posture, grip and take breaks Correct answer.

Explanation

Repetitive strain injuries develop gradually, so prevention focuses on neutral posture, a relaxed grip, correctly sized tools and frequent short breaks with stretching. Pain that persists should be evaluated by a physician rather than ignored.

Question 24Infection Control, Sanitation, and Safety Practices

During a consultation you notice tiny oval nits firmly attached to the hair shafts and the client's scalp is itchy. What is the correct action?

  1. Apply a deep conditioning treatment and continue
  2. Cut the affected hair and proceed with the service
  3. Shampoo the hair thoroughly and continue the service
  4. Decline the service and disinfect the items Correct answer.

Explanation

Nits cemented to the hair shaft along with an itchy scalp indicate pediculosis, a contagious parasitic infestation. The service should not be performed; the client is referred for treatment, and combs, brushes and contact surfaces are cleaned and disinfected before another client is served.

Question 25Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which layer of the hair shaft is the innermost core and may be entirely absent in fine or light-colored hair?

  1. Medulla Correct answer.
  2. Hair bulb
  3. Cortex
  4. Cuticle

Explanation

The hair shaft is built from three layers: the medulla (innermost core), the cortex (middle layer that gives strength, elasticity, and holds pigment), and the cuticle (tough outer covering of overlapping scales). The medulla is often missing in fine or light-colored hair. The hair bulb is a structure at the base of the root, not a layer of the shaft.

Question 26Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which layer of the skin is the outermost and thinnest layer?

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

Explanation

The skin has three main layers: the epidermis on the outside, the dermis in the middle, and the subcutaneous layer at the base. The epidermis is the thin, protective outer layer that constantly renews itself. The papillary layer is a sublayer found within the dermis, not a separate skin layer.

Question 27Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

On the pH scale, a value of 7 indicates which type of solution?

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

Explanation

The pH scale runs from 0 to 14, with 7 at the exact midpoint. A solution at 7 is neutral, meaning it is neither acidic nor alkaline. Values below 7 are acidic and values above 7 are alkaline.

Question 28Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which gland is attached to a hair follicle and secretes sebum onto the skin?

  1. Sebaceous gland Correct answer.
  2. Sudoriferous gland
  3. Eccrine gland
  4. Apocrine gland

Explanation

Sebaceous glands are the oil glands of the skin, usually connected to hair follicles, and their secretion (sebum) lubricates the skin and hair. Sudoriferous glands are sweat glands and belong to a separate category. Eccrine and apocrine glands are both types of sudoriferous glands.

Question 29Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

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

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

Explanation

The hair growth cycle has three main phases: anagen (active growth), catagen (transition), and telogen (resting and shedding). Anagen is the growth phase and lasts from roughly two to six years. Lanugo is fine fetal hair, not a phase of the adult cycle.

Question 30Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which structure at the base of the nail contains nerves, lymph, and blood vessels and creates new nail cells?

  1. Hyponychium
  2. Lunula
  3. Eponychium
  4. Nail matrix Correct answer.

Explanation

The nail matrix is the tissue at the base of the nail that holds nerves, lymph, and blood vessels and produces new cells; those cells keratinize to become the nail plate. The lunula is the visible whitish half-moon of the matrix. The eponychium is the cuticle and the hyponychium is the skin beneath the free edge.

Question 31Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

A chemical bond formed when one atom gives up an electron to another atom is called a(n):

  1. Covalent bond
  2. Hydrogen bond
  3. Ionic bond Correct answer.
  4. Metallic bond

Explanation

In an ionic bond, one atom loses an electron and another gains it, producing oppositely charged ions that attract each other. In a covalent bond, atoms share electrons rather than transfer them. Hydrogen bonds are weaker attractions between molecules and do not involve electron transfer.

Question 32Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

An inflamed, elevated lesion containing pus, such as a pimple, is best described as a:

  1. Wheal
  2. Macule
  3. Papule
  4. Pustule Correct answer.

Explanation

A pustule is a small, elevated, inflamed lesion filled with pus. A papule is a raised lesion without pus, a macule is a flat spot of color change, and a wheal is an itchy, swollen bump such as a hive.

Question 33Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which muscle draws the eyebrows down and together, creating vertical wrinkles between the brows?

  1. Temporalis
  2. Occipitalis
  3. Masseter
  4. Corrugator Correct answer.

Explanation

The corrugator muscle lies between and slightly above the brows and pulls them together and down, producing frown lines. The occipitalis is at the back of the skull, the masseter is a chewing muscle at the angle of the jaw, and the temporalis covers the temple.

Question 34Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

In a solution, the substance that does the dissolving is called the:

  1. Surfactant
  2. Emulsion
  3. Solute
  4. Solvent Correct answer.

Explanation

A solution has two parts: the solute, which is dissolved, and the solvent, which does the dissolving. Water is the most common solvent in cosmetic products. A surfactant is a surface-active cleansing ingredient, and an emulsion is a blend of two immiscible liquids.

Question 35Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which pigment is primarily responsible for black and dark brown hair color?

  1. Hemoglobin
  2. Keratin
  3. Pheomelanin
  4. Eumelanin Correct answer.

Explanation

Melanin exists in two forms in hair: eumelanin, which produces black and brown tones, and pheomelanin, which produces red and blond tones. Keratin is the protein that builds hair, and hemoglobin is the oxygen-carrying pigment of blood.

Question 36Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

A fungal infection of the natural nail plate is called:

  1. Onycholysis
  2. Onychorrhexis
  3. Onychomycosis Correct answer.
  4. Paronychia

Explanation

Onychomycosis is a fungal infection of the nail plate; a cosmetologist should not service the nail and should refer the client to a physician. Onychorrhexis refers to brittle, split nails, onycholysis is separation of the nail plate from the bed, and paronychia is inflammation of the tissue surrounding the nail.

Question 37Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Blood vessels, nerve endings, and sebaceous glands are found mainly in which skin layer?

  1. Subcutaneous layer
  2. Dermis Correct answer.
  3. Epidermis
  4. Stratum corneum

Explanation

The dermis is the middle, thicker layer of the skin and holds blood vessels, nerves, lymph vessels, oil and sweat glands, and hair follicles. The epidermis has no blood vessels of its own. The subcutaneous layer lies beneath the dermis and consists mainly of fat and connective tissue.

Question 38Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Most cells of the human body reproduce through a process called:

  1. Mitosis Correct answer.
  2. Meiosis
  3. Osmosis
  4. Phagocytosis

Explanation

Mitosis is the division of a cell into two identical daughter cells and is how most body tissues grow and repair themselves. Meiosis produces reproductive cells, osmosis is the movement of water across a membrane, and phagocytosis is a cell engulfing particles.

Question 39Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

A mixture of two or more immiscible liquids held together by an emulsifier is a(n):

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

Explanation

An emulsion blends two liquids that would otherwise separate, such as oil and water, with the help of an emulsifier. A solution has fully dissolved ingredients and is usually clear, while a suspension has undissolved particles temporarily dispersed in a liquid.

Question 40Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which nerve controls the muscles of facial expression that a cosmetologist works with during a facial massage?

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

Explanation

The facial nerve (cranial nerve VII) supplies the muscles of facial expression, which are the muscles manipulated during facial massage. The trigeminal nerve is the chief sensory nerve of the face and also controls the chewing muscles. The occipital and brachial nerves serve other regions of the head and arm.

Question 41Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The outermost layer of the epidermis, composed of flattened, keratinized dead cells, is the:

  1. Stratum corneum Correct answer.
  2. Stratum granulosum
  3. Stratum lucidum
  4. Stratum spinosum

Explanation

The stratum corneum is the horny outer layer of the epidermis, made of dead, keratin-filled cells that shed continuously and form the skin's first barrier to the environment. The granulosum, spinosum, and lucidum layers all lie deeper within the epidermis.

Question 42Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The term for excessive hair growth in areas where hair does not normally grow is:

  1. Alopecia areata
  2. Hirsuties Correct answer.
  3. Canities
  4. Telogen effluvium

Explanation

Hirsuties refers to excessive hair growth in areas where hair would not normally grow, commonly on the face. Alopecia areata is patchy hair loss, canities is gray or whitened hair, and telogen effluvium is excessive shedding of hairs in the resting phase.

Question 43Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Ammonia, a common ingredient in permanent hair color, is best classified as:

  1. An alkaline agent Correct answer.
  2. An acid
  3. A neutral solution
  4. A salt

Explanation

Ammonia has a pH well above 7, so it is alkaline; it swells the cuticle so color molecules can enter the cortex. Acids have a pH below 7, and a truly neutral solution sits at pH 7.

Question 44Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Apocrine sweat glands typically become active at which time of life?

  1. At birth
  2. At puberty Correct answer.
  3. In early childhood
  4. After age 60

Explanation

Apocrine glands are located mainly in the underarms and genital area and remain inactive until puberty, when hormonal changes switch them on; they produce a thicker secretion that bacteria break down into body odor. Eccrine glands, by contrast, are active from birth.

Question 45Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The two bones that form the upper jaw are the:

  1. Mandible
  2. Nasal bones
  3. Maxillae Correct answer.
  4. Zygomatic bones

Explanation

The maxillae are the two bones of the upper jaw; they hold the upper teeth and help form the eye socket and sides of the nose. The mandible is the lower jaw, the zygomatic bones form the cheekbones, and the nasal bones form the bridge of the nose.

Question 46Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The spleen, thymus, lymph nodes, and lymph vessels make up which body system?

  1. Lymphatic system Correct answer.
  2. Endocrine system
  3. Muscular system
  4. Integumentary system

Explanation

The lymphatic system consists of lymph, lymph vessels, lymph nodes, the spleen, and the thymus; it drains excess tissue fluid and helps fight infection. The endocrine system is made up of hormone-secreting glands such as the thyroid and adrenal glands.

Question 47Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The acid mantle that protects the surface of the skin is best described as:

  1. Alkaline, about pH 9
  2. Slightly acidic, about pH 4.5 to 5.5 Correct answer.
  3. Neutral, about pH 7
  4. Strongly acidic, about pH 1

Explanation

The acid mantle is a thin film of sebum and sweat on the skin with a pH of roughly 4.5 to 5.5, which discourages bacteria and helps the skin hold moisture. Products with a pH far outside this range can disrupt the barrier and leave skin dry or irritated.

Question 48Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

The whitish, half-moon-shaped area at the base of the nail plate is the:

  1. Lunula Correct answer.
  2. Free edge
  3. Nail bed
  4. Eponychium

Explanation

The lunula is the visible, paler portion of the nail matrix that shows at the base of the nail plate. The free edge extends past the fingertip, the eponychium is the living skin at the base of the nail, and the nail bed is the skin on which the plate rests.

Question 49Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

Which bonds must be broken and then re-formed to change the shape of hair permanently?

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

Explanation

Permanent waving uses a reducing agent to break the strong disulfide bonds in the cortex, reshapes the hair around rods, and then neutralizes to rebuild those bonds in the new position. Hydrogen and salt bonds are weaker, are easily broken by water or pH changes, and account only for temporary styling effects. Peptide bonds are part of the protein chain itself and are not rearranged in a normal wave.

Question 50Scientific Fundamentals: Anatomy, Physiology, Chemistry, and Disorders of Hair, Skin, and Nails

A solution with a pH of 5 is how many times more acidic than a solution with a pH of 7?

  1. 100 times Correct answer.
  2. 1,000 times
  3. 2 times
  4. 10 times

Explanation

The pH scale is logarithmic, so each single-unit change represents a tenfold change in acidity. Moving two units (from 7 to 5) therefore means 10 × 10, or 100 times greater acidity.