Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
46 Cards in this Set
- Front
- Back
units of information about inherited traits that can be passed from one generation to the next
|
genes
|
|
different forms of a gene
|
alleles
|
|
two chromosomes of each pair in a diploid cell that are alike in length, shape and genes
|
homologous chromosomes
|
|
when homologous chromosomes exchange corresponding segments
|
crossing over
|
|
name for combinations of alleles in gametes, then in offspring, that were not present in a parent
|
genetic recombination
|
|
pairs of chromosomes that are the same in males and females
|
autosomes
|
|
pairs of chromosomes that govenr a new individual's gender
|
sex chromosomes
|
|
a diagram that can help answer questions about a person's chromosomes.
|
karyotype
|
|
chemical that arrests mitosis at metaphase during a karyotype
|
colchicine
|
|
most or all of the genes on one of a female's x chromosomes are "switched off" soon after the first cleavages of the zygote
|
x inactivation
|
|
condition occurring in females in whom mutated gene that blocks the formation of sweat glands
|
anhidrotic ectodermal dysplasia
|
|
genetic family history
|
pedigree chart
|
|
deviation from the average
|
abnormality
|
|
causes mild to severe medical problems
|
disorder
|
|
a set of symptoms that characterize a disorder
|
syndrome
|
|
condition resulting from abnormal buildup of the amino acid phynylalanine
|
phynylketonuria (PKU)
|
|
condition in which an individual lacks hexosaminidase A, the enzyme required for the metahbolism of sphingolipids that are espciall y abundant in the plasma membrane of cells in nerves and the brain, causes loss of motor functions, deabness blindness , mental retardation and often death in early childhood
|
Tay-Sachs disease
|
|
diesase in which the basal nuclei of the brain degenerate, homozygootes die as embryos
|
Huntington disease
|
|
condition results in weakened connective tissues in many body structures including aorta, often results in death due to a blood vessel rupture before age 50
|
Marfan syndrome
|
|
condition in which cartilage elementos of bones do not form properly, hymozygoutes are usually stillborn, adults are usually under 4'4" tall
|
achondroplasia
|
|
condition in which dangerously elevated blood cholesterol
|
familial hypercholesterolemia
|
|
gene sequences that are repeated
|
duplications
|
|
part of one chromosome exchanges places with a corresponding part of another chromosome that is not its homologous partner
|
translocation
|
|
loss of a gene that may be caused spontaneously, or by a virus or by irradiation or some other environmental factor including but not limited to chemical assaults
|
deletion
|
|
disorder in which the deletion of human chromosome 5 leads to mental retardation and an abnormally shaped larynx resulting in a cat cry
|
cri-du-chat
|
|
a change in one or more of the nucleotides that make up a particular gene
|
mutation
|
|
condition in which the embryo doesn't have an exact multiple of the normal haploid set of 23 chromosomes
|
aneuploidy
|
|
a ______ embryo has three, four or more sets of the normal haploid set of 23 chromosomes. All but 1 % die before birth and the rare newborns die soon afterward
|
polyploid
|
|
one or more pairs of chromosomes fail to separate during mitosis or meiosis, resulting in too many or too few crhomosomes
|
nondisjunction
|
|
when fertilization brings together a geamete with an extra chromosome resulting in 3 of one type of chromosome
|
trisomy
|
|
when fertilzation results in the agamete missing a chromosome the the result is ______
|
monosomy
|
|
When a nondisjunction has reduced the chromosome number to 45, resulting in individuals who are missing an x chromosome
|
Turner syndrome
|
|
How do X and Y chromosomes differ?
|
X chromosomes are female and Y chromosomes are male
|
|
What do we mean when we say someone is a carrier of a genetic trait
|
they have the ability to pass on the trait as they carry the recessive allele, but due to they are not affected by it.
|
|
What evidence indicates that a trait is coded by a dominant allele on an autosome?
|
the trait usually appears in each generation
|
|
Explain the difference in an X-linked trait and a sex influenced trait
|
X-linked genetic disorders occurwhen the mutated gene is on the X chromosome, typically affecting males who inherit only one X chromosome, Sex-influenced traits appear more frequently in one sex.
|
|
Give two examples of phenotypes that can result from nondisjunction
|
Turner Syndrome
XXX females Klinfelter syndrome xyy condition |
|
Genetic disorders can be caused by _____.
A gene mutations B. changes in chromosome structure C. changes in chromosome number D. all of the above |
D
|
|
______ segregate during _____.
A Homologues; mitosis B. Genes on one chromosome; meiosis C. Homologues; meiosis D. Genes on one chromosome; mitosis |
C
|
|
The alleles of a gene on homologous chromosomes end up in separate _____.
A. body cells B. gametes C. nonhomologous chromosomes D. offspring E. both B and D are possible |
E
|
|
Genes on the same chromosome tend to remain together during _____ and end up in the same _____.
A. mitosis; body cell B. mitosis; gamete C. meiosis; body cell D. meiosis; gamete E. both A and D |
E
|
|
The probability of a crossover occurring between two genes on the same chromosome is _____.
A. unrelated to the distance between them B. increased if they are closer together on the chromosome C. increased if they are farther apart on the chromosome D. zero |
C
|
|
A chromosome's structure can be altered by _____.
A. deletions B. duplications C. translocations D. all of the above |
D
|
|
Nondisjunction can be caused by _____.
A. crossing over in meiosis B. segregation in meiosis C. failure of chromosomes to separate during meiosis D. multiple independent assortments |
C
|
|
A gamete affected by nondisjunction could have _____.
A. a change from the normal chromosome number B. one extra or one missing chromosome C. the potential for a genetic disorder D. all of the above. |
D
|
|
A person who is a carrier for a genetic trait _____.
A. is heterozygous for a dominant trait B. is heterozygous for a recessive trait C. is homozygous for a recessive trait D. could be either A or B but not C. |
D
|