1.
The portion of the hair that extends above the skin or scalp.
Correct Answer
A. Hair shaft
Explanation
The hair shaft refers to the portion of the hair that extends above the skin or scalp. It is the visible part of the hair that we can see and touch. The hair shaft is made up of dead, keratinized cells that have been pushed up from the hair follicle. It is responsible for giving hair its color, texture, and length. The hair shaft is different from the hair root, which is the part of the hair that is located below the skin or scalp and anchors the hair in place. The hair bulb, on the other hand, is the rounded base of the hair follicle where the hair root begins.
2.
The tough outer protective covering of hair.
Correct Answer
A. Cuticle
Explanation
The correct answer is cuticle. The cuticle is the tough outer protective covering of hair. It is a thin, transparent layer that surrounds the hair shaft and helps to protect it from damage. The cuticle also plays a role in maintaining the moisture balance of the hair and preventing it from becoming too dry or too brittle.
3.
The ________ is the middle layer of the hair.
Correct Answer
B. Cortex
Explanation
The cortex is soft, thick and made up of elongated cells. It also contains melanin pigment. The elasticity of the hair and it's natural color are the result of the unique protein structures located within the cortex. The changes involved in oxidation hair coloring, wet setting, thermal styling, permanent waving, and chemical hair relaxing all take place within the cortex.
4.
Gray hair is caused by the absence of melanin.
Correct Answer
A. True
Explanation
Gray hair grows from the hair bulb in exactly the same way that pigmented hair grows and has exactly the same structure, but without the melanin pigment.
5.
Hair growth occurs in cycles. Each complete cycle has three phases that are repeated over and over again throughout life. The three phases are anagen, catagen, and telogen.
Correct Answer
A. True
Explanation
Hair growth occurs in cycles, with each cycle consisting of three phases: anagen, catagen, and telogen. These phases are repeated throughout a person's life. During the anagen phase, the hair actively grows, while in the catagen phase, the hair stops growing and detaches from the blood supply. Finally, during the telogen phase, the hair rests before falling out and being replaced by a new hair. Therefore, it is true that hair growth occurs in cycles with these three phases.
6.
During the ________ or growth phase, new hair is produced. The hair actively manufactures new keratinized cells in the hair follicle. During this phase, hair cells are produced faster than any other normal cell in the human body.
Correct Answer
C. Anagen
Explanation
The average growth of healthy scalp hair is about 1/2 inch per month. Scalp hair grows faster on women than on men. Scalp hair grows rapidly between the ages of 15 and 30 but slows down sharply after the age of 50. About 90% of scalp hair is growing in the anagen phase at any one time. For each specific hair, the anagen phase generally lasts from three to five years, but in some cases, it can last as long as ten years.
7.
Name the outside layer of the hair.
Correct Answer
A. Cuticle
Explanation
The cuticle is the outermost layer of the hair. It is a thin, transparent layer that acts as a protective barrier for the hair shaft. The cuticle is made up of overlapping scales that help to prevent damage and keep the hair shaft moisturized. It also plays a role in giving the hair its shine and smoothness. The other options, follicle, cortex, and medulla, are not the correct answers as they refer to different parts of the hair structure.
8.
A Medulla is not present in all hair
Correct Answer
A. True
Explanation
The medulla is the innermost layer of the hair shaft and is not present in all hair types. Some hair types, such as fine or thin hair, may not have a medulla. Therefore, the statement "A Medulla is not present in all hair" is true.
9.
Put the layers in order, starting from outside.
Correct Answer
D. Cuticle, Cortex, Medulla
Explanation
The cuticle is the outermost layer of the hair shaft, followed by the cortex, which is the middle layer, and finally the medulla, which is the innermost layer. This order is important because the cuticle acts as a protective barrier for the cortex and medulla, and the cortex provides strength and structure to the hair. The medulla, although not always present in all hair types, is responsible for the hair's flexibility and elasticity. Therefore, the correct order of the layers from outside to inside is cuticle, cortex, medulla.
10.
Trace evidence is a type of circumstantial evidence, examples of which include:
Correct Answer
D. All of these choices
Explanation
The given correct answer is "All of these choices". This means that all of the examples mentioned - hair found on a brush, fingerprints found on a glass, and blood drops on a shirt - are types of trace evidence. Trace evidence refers to any small, physical material that is left behind at a crime scene and can be used to link a suspect to the crime. In this case, all three examples mentioned are types of physical evidence that can be collected and analyzed to help solve a crime.