Chapter 6: Genetics

Question 0

The Lyon hypothesis is demonstrated by:

Answer 0

X-linked recessive traits

Question 1

The short and long arms of each chromosome are joined by a constriction called the:

Answer 1

Centromere

Question 2

Trisomy is defined as:

Answer 2

A pair of chromosomes with an identical extra chromosome

Question 3

The process by which a primitive germ cell becomes a gamete is called:

Answer 3

Meiosis

Question 4

Barr bodies are seen at the:

Answer 4

Nuclear periphery of cells in women

Question 5

The karyotype of a patient with Turner syndrome shows:

Answer 5

44 autosomes and XO

Question 6

Hypothetically, an autosomal-dominant trait would be clinically present in:

Answer 6

50% of the offspring of an affected parent

Question 7

Patients with an X-linked hereditary condition:

Answer 7

Are generally affected more severely if they are men

Question 8

Which one of the following is associated with cyclic neutropenia?

Answer 8

Diminished number of circulating neutrophils

Question 9

In all inherited varieties of gingival fibromatosis, the gingival enlargement is characterized by a marked:

Answer 9

Collagenization of the connective tissue

Question 10

A 14-year-old boy is seen in consultation because of bilateral Mandibular swelling. Radiographs show a bilateral multilocular lesion in the ascending Mandibular rami. The mother of this patient has similar findings. The most likely diagnosis is:

Answer 10

Cherubism

Question 11

A 9-year-old boy exhibits markedly swollen red and bleeding gingiva. In addition, he has tooth mobility, and the intraoral radiographs show marked alveolar bone atrophy with vertical periodontal pockets. Which of the following will be found in this child if he were to have Papillon-Lefèvre syndrome?

Answer 11

Palmar and plantar hyperkeratosis

Question 12

Which of the following is the most serious component of Gardner syndrome?

Answer 12

Intestinal polyposis

Question 13

A 19-year-old woman is diagnosed with cleidocranial dysplasia. She has absent clavicles and a mushroom-shaped skull. Which of the following conditions is she also most likely to have?

Answer 13

Supernumerary teeth

Question 14

Odontogenic keratocysts are a clinical component of:

Answer 14

Nevoid basal cell carcinoma syndrome

Question 15

Two characteristic clinical components of mandibulofacial dysostosis are:

Answer 15

Hypoplastic mandible and deafness

Question 16

Torus mandibularis and torus palatinus are:

Answer 16

Inherited as an autosomal-dominant trait

Question 17

The major concern for a dental hygienist when treating a patient with Osler-Rendu–Parkes Weber syndrome should be:

Answer 17

Gingival hemorrhage

Question 18

The cause of all forms of labial and palatal clefting is considered to be:

Answer 18

Multifactorial

Question 19

Which of the following is true for Von Recklinghausen disease?

Answer 19

Patients may have gingival neurofibromas

Question 20

The most serious clinical manifestation of the MEN 2B syndrome is considered to be:

Answer 20

Carcinoma of the thyroid gland

Question 21

Teeth in snowcapped amelogenesis imperfecta have:

Answer 21

White hypocalcified enamel at the incisal and occlusal thirds

Question 22

In dentinogenesis imperfecta type II, teeth have:

Answer 22

Roots that are short and thin

Question 23

Patients with hypohidrotic ectodermal dysplasia characteristically have:

Answer 23

Hypodontia

Question 24

Patients with hypophosphatasia characteristically have:

Answer 24

Absence of root cementum

Question 25

Taurodontic teeth:

Answer 25

Are pyramidal in shape

Question 26

The characteristic finding in permanent teeth affected with coronal dentin dysplasia is:

Answer 26

Thistle-shaped pulp chambers on radiographs

Question 27

The order of the four stages of mitosis is:

Answer 27

Prophase, metaphase, anaphase, telophase

Question 28

The so-called “enamel agenesis” is one of which type of amelogenesis imperfecta?

Answer 28

Hypoplastic

Question 29

The most frequent site of hemorrhage in patients with hereditary hemorrhagic telangiectasia is the:

Answer 29

Nasal mucosa

Question 30

The Papillon-Lefèvre syndrome is inherited according to a(n)

Answer 30

Autosomal recessive pattern

Question 31

The most frequently exfoliated teeth in patients with hypophosphatasia are the

Answer 31

Mandibular primary incisors

Question 32

Which one of the following statements is true when comparing cyclic neutropenia and Kostmann syndrome?

Answer 32

The oral lesions in Kostmann syndrome are always present unless systemic treatment is instituted

Question 33

Which of the following is a component of the Peutz-Jeghers syndrome?

Answer 33

Multiple pigmented macules on the tip of the tongue

Question 34

Radiographs of a patient with radicular dentin dysplasia show

Answer 34

Pulp chambers with a half-moon appearance