Question 1

What is Tay-Sachs disease?

Accepted Answer

A fatal genetic disorder that causes the destruction of nerve cells in the brain and spinal cord

(inability to break down a particular type of lipid in the brain; recessive)

Question 2

What is cystic fibrosis (CF)?

Accepted Answer

A genetic disorder that causes thick mucus to accumulate in the lungs and digestive tract

(gene is located on chromosome 7; kills children at a young age if untreated)

Question 3

What is sickle cell anemia?

Accepted Answer

A recessive genetic disorder that causes hemoglobin to deform to a "sickle" shape, making it less efficient at carrying oxygen

(with only one copy, you get increased resistance to malaria, but with both copies, you get sickle cell anemia)

Question 4

What is phenylketonuria (PKU)?

Accepted Answer

A recessive genetic disorder that may lead to an intellectual disability if untreated

(causes inability to successfully digest an amino acid called phenylalanine)

Question 5

What is Huntington disease?

Accepted Answer

A fatal, dominant genetic disorder that causes the breakdown of the nervous system

(dominant, not recessive!; only appears when a person is in their 30s/40s)

Question 6

Why are lethal recessive alleles more common than lethal dominant alleles?

Accepted Answer

Individuals with lethal recessive alleles can live and reproduce perfectly fine, spreading the allele to their children

Individuals with lethal dominant alleles will most likely die before spreading the allele to their children

Question 7

What is aneuploidy?

Accepted Answer

An organism or cell having an unusual amount of chromosomes

(if a human had 45 of 47 chromosomes)

Question 8

What is Down syndrome (trisomy 21)?

Accepted Answer

An aneuploid disorder, leading to intellectual disability, heart defects, short stature, and abnormal facial features

(caused by an extra copy of chromosome 21)

Question 9

What is a trisomy?

Accepted Answer

A chromosomal condition where there is an extra copy of a chromosome

(trisomy 21 (Down syndrome) = extra copy of 21st chromosome)

Question 10

What is Patau syndrome (trisomy 13)?

Accepted Answer

A chromosomal abnormality causing serious brain and circulatory defects

Question 11

What is Edwards syndrome (trisomy 18)?

Accepted Answer

A genetic disorder that affects many body parts, causing developmental delays and a small/defective heart

(usually fatal before the first year)

Question 12

What is XYY syndrome?

Accepted Answer

A chromosomal disorder that causes males to get an extra Y chromosome (XYY)

(not too severe, but usually taller and possibly more aggressive than avg)

Question 13

What is Klinefelter syndrome?

Accepted Answer

A chromosomal disorder that causes males to receive an extra X chromosome (XXY)

Causes the male to have male sex organs, but display feminine body characteristics

Question 14

What is Turner syndrome?

Accepted Answer

A chromosonal disorder that causes females to miss an X chromosome (XO), and be sterile and lack mature sex organs

Question 15

What is a deletion in genetics?

Accepted Answer

When a piece of a chromosome (or an entire chromosome) is lost in development

Question 16

What is cri-du-chat?

Accepted Answer

A rare chromosonal disorder, where a deletion in chromosome 5 leads to intellectual disability

(French for "cat cry"; causes affected to have a cry like a cat)

Question 17

What are chromosomal translocations?

Accepted Answer

A chromosomal abnormality where a piece of one chromosome breaks and reattaches to a different chromosome

(can cause major problems)

Question 18

What is chronic myelogenous leukemia?

Accepted Answer

A disease caused by chromosomal translocation, resulting in bone marrow making too many white blood cells

(part of chromosome 22 is swapped with part of chromosome 9)

Question 19

What is a chromosome inversion?

Accepted Answer

A chromosomal abnormality where a portion of a chromosome separates and reattaches in the opposite direction

(can be harmless, but can also render a gene useless)

Question 20

What is a chromosome duplication?

Accepted Answer

A chromosomal abnormality that results in the repetition of a genetic segment

Disorders, AP Biology Flashcards