Chapter 2 Flashcards
Hereditary
the transmission of traits and characteristics from parent to child by means of genes
Genetic
The branch of biology that studies heredity
Gene
The basic unit of heredity. Genes are composed of deosyribonucleic acid (DNA)
Polygenic
Resulting from many genes
DNA
Genetic material that takes the form of a double helix made up of phosphates sugars and bases
zgote
a new cell formed from the union of a sperm an ovum (egg cell) a fertilized egg
Mitosis
The form of cell division in which each chromosome splits length wise to double in number. Half of each chromosome combines with chemicals to retake its original form and then moves forward
Mutation
A sudden variation in a heritable characteristic such as by an accident that affects the composition of genes
Meiosis
The form of cell division in which each pair of chromosomes splits so that one member of each moves to the new cell. As a result each new cell has 23 chromosomes
Autosome
a member of a pair of chromosomes (with the exception of sex chromosomes)
sex chromosome
a chromosome in the shape of a Y (male and X (female. that determines the sex of a child
Monozygotic twins
twins that derive from a single zygote that has split into two identical twins. Each MZ twin carries the same genetic code
Dizygotic Twins (DZ)
Twinsthat derive from two zygotes fraternal twins
Ovulation
the release of an ovum from an ovary
allelea
a MEMBER OF A PAIR OF GENES
Homozygous
Having two different alleles
Heterozygous
having two different alleles
dominant trait
A trait that is expressed
Recessive Trait
A trait that is not expressed when the gene or genes involved have been paired with dominant genes. Recessive traits are transmitted to future generations and expressed if they are paired with other recessive genes
Carrier
A person who carries and transmits characteristics but does not exhibit them
multifactorial problems
Problems that stem from the interaction of heredity and environmental factors
Down Syndrome
A chromosomal abnormality characterized by mental retardation and caused by an extra chromosome in the 21st pair
sex linked chromosomal abnormalities
abnormalities that are transmitted from generation to generation carried by a sex chromosome usually an X sex chromosome
Klinefelter syndrome
a chromosomal disorder found among males that is caused by an extra X sex chromosome and thjat is characterized by infertility and mild mental retardation
Testosterone
a male sex hormone produced by manily by the testes
Turner Syndrome
A chromosomal disorder found among females that is caused by having a single X sex chromosome and that is characterized by infertility
estrogen
a female sex hormone produced maily by the ovaries
phenylketonuria (PKU)
a genetic abnormality in which phenylalanine builds up and causes intellectual disability
Huntington Disease
A fatal genetic neurological disorder whose onset is in the middle age
Sickle Cell Anemia
A genetic disorder that decreases the bloods capacity to carry oxygen
Tay Sachs disease
a fatal genetic neurological disorder
Cystic fibrosis
A fatal genetic disorder in which mucus obstructs the lungs and pancreas
hemophilia
A genetic disorder in which blood does not clot properly
sex linked genetic abnormalties
abnormalities resulting from genes that are found on the x sex chromosome
alpha fetoproten assay
a blood test that asses the mothers blood level of alphafetoprotein a substance that is linked with fetal neural tube defects
canalization
the tendency of growth rates to return to genetically determined patterns after undergoing environmentally induced change
Reaction range
the variability in the expression of inherited traits as they are influenced by environmental factors
Phenotype
the actual form or consitution of a person as determined by heredity and environmental factors
