Chromosomal Abnormalities

Multiple Choice

Which of the following is NOT a type of chromosomal abnormality caused by breakage of chromosomes?

• Deletion

• Duplication

• Nondisjunction

• Translocation

Multiple Choice

What is nondisjunction and how does it affect chromosome number in daughter cells during meiosis?

• Nondisjunction is the failure of chromosomes to separate properly during mitosis, leading to identical daughter cells.

• Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate during meiosis, resulting in daughter cells with too many or too few chromosomes.

• Nondisjunction is the process by which chromosomes replicate twice during meiosis, causing extra chromosomes in daughter cells.

• Nondisjunction is the separation of chromosomes during mitosis, resulting in cells with half the chromosome number.

Multiple Choice

Compare the effects of nondisjunction in Meiosis I and Meiosis II on the chromosome number of resulting gametes.

• Nondisjunction in Meiosis I results in all gametes having the correct chromosome number, while Meiosis II results in all gametes having incorrect numbers.

• Nondisjunction in Meiosis I results in half of the gametes having incorrect chromosome numbers, while Meiosis II results in all gametes having incorrect numbers.

• Nondisjunction in Meiosis I results in all gametes having incorrect chromosome numbers, while nondisjunction in Meiosis II results in half of the gametes having incorrect numbers.

• Both Meiosis I and Meiosis II nondisjunction result in the same number of incorrect gametes.

Open Ended

Explain the difference between trisomy and monosomy and how each condition arises from nondisjunction.

Hotspot

Select the abnormal set of chromosomes in the picture provided.

Multiple Select

Human chromosome disorders often result from biochemical imbalance. List two possible regulatory molecules that may be affected and describe their role in development.

• hormones

• transcritpion factors

• low cAMP

• improper ligand binding

Fill in the Blanks

Down syndrome is caused by

copies of chromosome 21.

Multiple Choice

Which of the following statements about the relationship between maternal age and the incidence of Down syndrome is correct?

• The incidence of Down syndrome decreases as maternal age increases.

• The incidence of Down syndrome remains constant regardless of maternal age.

• The incidence of Down syndrome increases as maternal age increases.

• Maternal age has no effect on the incidence of Down syndrome.

Multiple Choice

Which genetic testing procedure is used in the 2nd trimester to analyze the karyotype of an embryo?

• Amniocentesis

• Ultrasound

• Blood test

• MRI

Open Ended

Explain how abnormalities in sex chromosomes can lead to distinct syndromes in humans. Use examples from the slides.

Multiple Select

Which of the following are characteristics of Klinefelter’s syndrome (XXY male)?

• Sterile

• Tall

• Normal intelligence

• Delayed emotional maturity

Fill in the Blanks

Klinefelter’s syndrome is caused by the presence of an extra

chromosome in males.

Open Ended

Compare the karyotypes shown for Klinefelter’s syndrome and Jacob’s syndrome. What is the key chromosomal difference between these two conditions?

Multiple Choice

What is the biological reason that females with Trisomy X (XXX) are generally healthy?

• All but one X chromosome is inactivated

• The extra X chromosome is deleted

• The extra X chromosome is duplicated

• The extra X chromosome is converted to a Y chromosome

Fill in the Blanks

A person with Turner syndrome has

sex chromosomes.

Multiple Choice

Which of the following is NOT a typical symptom or characteristic of Turner syndrome?

• Webbed neck

• Short stature

• Sterile

• Excessive height

Open Ended

Explain how changes in chromosome structure such as deletion, duplication, inversion, and translocation can impact genetic disorders. Use examples from the images.

Multiple Choice

Which of the following is NOT a type of chromosomal breakage abnormality?

• Deletion

• Duplication

• Nondisjunction

• Inversion

Open Ended

What are some possible consequences of errors during meiosis, and how might they affect an individual?