Chapter 2 Heredity And Conception, Prenatal Development Flashcards
Heredity
Transmission of traits and characteristics from parent to child by genes
Genetics
The study of heredity
Chromosomes
Structures that are composed of genes and found within nuclei of cells, rod shaped
Gene
Basic unit of heredity composed of DNA
Polygenic
Resulting from many genes
Deoxyribonucleic Acid
Genetic material that takes the form of a double helix made up of phosphates, sugars, and bases
Zygote
An egg formed when the sperm and ovum join together
Mitosis
The form of cell division when chromosomes split lengthwise to double in number
Mutation
A sudden variation in a heritable characteristic affecting the composition of genes
Meiosis
The form of cell division in which each pair of chromosome splits and one member of each pair moves to the cell
Auto some
A member of a pair of chromosomes with the exception of sex chromosomes
Sex Chromosome
A chromosome that determines the sex of a child. X for a girl and Y for a boy.
Monozygotic Twins
Twins that derive from a single zygote that split into two identical twins
Dizygotic Twins
Twins that derive from two zygotes
Ovulation
The release of an ovum from an ovary
Allele
A member of a pair of genes
Homozygous
Having two identical alleles
Heterozygous
Having two different alleles
Dominant Trait
A trait that is expressed
Recessive Trait
A trait that is not expressed when the gene of genes involved have been paired with dominant genes. The traits are transmitted to future generations and expressed if paired with other recessive genes
Carrier
A person who carries and transmits characteristics but does not exhibit them
Multifactoral Problems
Problems that stem from heredity and environmental factors interacting
Down Syndrome
A chromosomal abnormality characterized by intellectual disability and caused by an extra 21st chromosome. Also known as Trisomy 21.
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 X sex chromosome and is characterized by infertility and mild intellectual disability
Testosterone
A male sex hormone produced mainly by the testes