Skeletal and Muscle System (Human Anatomy and Physiology)

Total Questions: 32

21. Plaques formed on teeth are made up of— [U.P.P.C.S. (Mains) 2004]

Correct Answer: (d) Food particles plus saliva plus mouth acids plus bacteria
Solution:

Dental plaque is a biofilm or mass of bacteria that grows on surfaces within the mouth. It appears as a white/pale yellow ‘slime layer’ commonly found in between the teeth and along the cervical margins.

Plaques formed on teeth are made up of food particles, saliva, mouth acids and bacteria in the oral cavity. Saliva has a normal pH range of 6.2-7.6 with 6.7 being the average pH.

22. No pain is felt while cutting the nails because— [M.P.P.C.S. (Pre) 1994]

Correct Answer: (a) Nails are made of the material of dead cells in which there is no blood circulation.
Solution:

Nails are usually made up of thick and multiple layers of a type of protein known as α-keratin and are composed of dead tissues. They are devoid of any nerves and blood vessels and therefore we do not feel any pain while the nails are being cut.

23. Alpha-keratin is a protein, present in : [U.P.P.C.S. (Mains) 2003, I.A.S. (Pre) 1997]

Correct Answer: (b) Skin
Solution:

Alpha-keratin is a family of fibrous structural proteins. It is the key structural material making up the outer (epidermis) layer of human skin. It is the key structural component of hair, nails, hooves, and it provides the necessary strength and toughness for mastication organs, such as the tongue and the hard palate.

24. Hair is composed of protein called— [U.P.P.C.S. (R.I.) 2014]

Correct Answer: (c) Keratin
Solution:Hair is composed of the protein keratin, which is also the primary component of finger and toe nails. Keratin is a key structural protein found in various parts of the body, including hair, nails, and the outer layer of skin (epidermis).

It helps to protect cells from damage and provides strength and resilience to these tissues. Hair is composed of keratin cells, which are produced in the hair follicle and undergo a process called keratinization. This process transforms the cells into tough, non-living keratin fibers that form the hair shaft.

25. Which one of the following proteins is present in human hair and nails? [U.P.R.O./A.R.O (Pre) 2014]

Correct Answer: (b) Keratin
Solution:Keratin is an extremely strong protein that is a major component in skin, hair, nails, hooves, horns and teeth. Keratin is a key structural protein found in various parts of the body, including hair, nails, and the outer layer of skin (epidermis).

It helps to protect cells from damage and provides strength and resilience to these tissues. Hair is composed of keratin cells, which are produced in the hair follicle and undergo a process called keratinization. This process transforms the cells into tough, non-living keratin fibers that form the hair shaft.

26. Which of the following are required for the formation of bones and teeth? [U.P.P.C.S. (Mains) 2011]

Correct Answer: (d) Calcium and Phosphorus
Solution:

Teeth and bones both are hard, white and heavy. Teeth are composed of calcium, phosphorous and other minerals. Bones contain calcium, phosphorus, sodium and other minerals, but mostly consist of the protein collagen.

27. Which one of the following nutritional elements is not essential for the formation and strengthening of bones and teeth? [U.P.P.C.S. (Pre) 2015]

Correct Answer: (d) Iodine
Solution:

Calcium, phosphorus, and fluorine are essential elements for the formation and strengthening of bones and teeth. Deficiency of these nutritional elements may cause teeth and bone diseases, while iodine is used to control thyroid gland.

28. The number of teeth that are developed twice in the lifetime of human being is [39th B.P.S.C. (Pre) 1994]

Correct Answer: (c) 20
Solution:

In human life span, 20 teeth developed twice. Like a human, most of the mammals are diphyodont – It means our 12 permanent molars are monophyodont and others diphyodont. There are four types of teeth– Incisors, canines, premolars and molars.

29. Which of the following is the strongest part of our body ? [Uttarakhand U.D.A./L.D.A. (Pre) 2003]

Correct Answer: (b) Enamel
Solution:

Tooth enamel is the thin outer covering of the tooth and the strongest part of our body. It makes our teeth white and it exists to protect the crowns of healthy teeth. Tooth decay is due to the destruction of tooth enamel. It is made up of hydroxyapatite crystals, which is mainly calcium phosphate.

30. Which one of the following statements is incorrect about muscles in human body? [68th B.P.S.C. (Pre) 2022]

Correct Answer: (a) Muscles can only push the bone.
Solution:Muscles allow a person to move, speak, and chew. They control heartbeat, breathing, and digestion. Other seemingly unrelated functions, including temperature regulation and vision, also rely on the muscular system.

Muscles have a range of functions from pumping blood and supporting movement to lifting heavy weights or giving birth.

Muscles work by either contracting or relaxing to cause movement. Muscles work in pairs and become shorter, stiffer and thicker when contracted. So, statement of option (a) is incorrect.