9Th Grade Bio Ch. 26 Vocab

Front 1

genetic counseling

Back 1

prospective parents consult a counselor who determines the genotype of each and whether an unborn child will have a genetic disorder

Front 2

syndrome

Back 2

group of symptoms that appear together and tend to indicate the presence of a particular disorder

Front 3

karyotype

Back 3

chromosomes arranged by pairs according to their size, shape, and general appearance in mitotic metaphase; any body cell, except for red body cells (as they lack a nucleus), can be used for karyotyping; in adults, white blood cells are the easiest subjects for karyotyping

Front 4

amniocentesis

Back 4

procedure for removing amniotic fluid surrounding the developing fetus, using a needle, in order to test the fluid or cells within the fluid

Front 5

chorionic villi sampling (CVS)

Back 5

prenatal test in which a sample of chorionic villi cells is removed from the uterus, using a suction tube, for diagnostic purposes

Front 6

nondisjunction

Back 6

failure of homologous chromosomes or daughter chromosomes to separate during meiosis I and meiosis II, respectively

Front 7

trisomy

Back 7

an extra chromosome in the fetus due to nondisjunction

Front 8

monosomy

Back 8

a lacking of one chromosomes in the fetus due to nondisjunction

Front 9

Barr body

Back 9

dark-staining body in teh nuclei of female mammals that contains a condensed inactive X chromosome

Front 10

chromosomal mutation

Back 10

variation in regard to the normal number of chromosomes inherited or in regard to the normal sequence of alleles on a chromosome; the sequence can be inverted, translocated from a nonhomologous chromosome, deleted, or dpublicated

Front 11

deletion

Back 11

change in chromosome structure in which the end of a chromosome breaks off, or two simultaneous breaks lead to the loss of an internal segment; often causes abnormalities

Front 12

duplication

Back 12

change in chromosome structure in which a particular segment is present more than once

Front 13

inversion

Back 13

change in chromosome structure in which a segment of a chromosome is turned around 180 degrees; this reversed sequence of genes can lead to altered gene activity and abnormalities

Front 14

Tay-Sachs disease

Back 14

lethal genetic disease in which the newborn has a faulty lysosomal digestive enzyme; results from a lack of the enzyme hexosaminidase A (Hex A) and the subsequent storage of its substrate, a glycosphingolipid, in lysosomes; causes the patient to become blind helpless, develop uncontrollable seizures, and eventually become paralyzed; prevalent among American Jews

Front 15

cystic fibrosis (CF)

Back 15

a generalized autosomal recessive disorder of infants and children characterized by widespread dysfunction of the exocrine glands and accumulation of thick mucus in the lungs

Front 16

phenylketonuria (PKU)

Back 16

condition caused by the accumulation of phenylalanine; characterized by mental retardation, light pigmentation, eczema, and neurologic manifestations unless treated with a diet low in phenylalanine

Front 17

sickle cell disease

Back 17

hereditary disease due to a mutation in the hemoglobin gene, in which red blood cells are narrow and curved so that they are unable to pass through capillaries and are destroyed, leading to chronic anemia; sickle cell heterozygotes only exhibit the sickle cell symptoms if the red blood cells experience dehydration or mild oxygen depravation

Front 18

Marfan syndrome

Back 18

congenital disorder of connective tissue, fibrillin, characterized by abnormal length of the limbs

Front 19

Huntington's disease

Back 19

genetic disease marked by progressive deterioration of the nervous system due to deficiency of a neurotransmitter; signs of Huntington's tend to appear around middle age

Front 20

familial hypercholesterolemia (FH)

Back 20

inability to remove cholesterol from the bloodstream; predisposes individual to heart attacks; FH is determined by the number of LDL-cholesterol receptor proteins in the plasma membrane; a person with two mutated alleles lacks LDL-cholesterol receptors, a person with one mutated allele has half the normal number of receptors, and a person with two normal alleles has the normal number of receptors

Front 21

color blindness

Back 21

deficiency in one or more of the three kinds of cones responsible for color vision

Front 22

Duchenne muscular dystrophy

Back 22

chronic progressive disease affecting the shoulder and pelvic girdles, commencing in early childhood; characterized by increasing weakness of the muscles, followed by atrophy and a peculiar swaying gait with the legs kept wide apart; the condition is transmitted as an X-linked trait and affected individuals, predominantly males, rarely survive to maturity; death is usually due to respiratory weakness or heart failure

Front 23

hemophilia

Back 23

X-linked recessive genetic disease in which one or more clotting factors are missing

a. factor VIII, resulting in Hemophilia A

b. factor IX, resulting in Hemophilia B

Front 24

genetic marker

Back 24

abnormality in the sequence of a base at a particular location on a chromosome, signifying a disorder

Front 25

DNA probe

Back 25

piece of single-stranded DNA that will bind to a complementary piece of DNA

Front 26

genetic profiling

Back 26

an individual's complete genotype, including any possible mutations