Download OUR GENES, OUR SELVES VOCABULARY

OUR GENES, OUR SELVES
VOCABULARY
1. MODEL: A description or concept of a system or set of observable events that accounts for all its known properties in a reasonable way. Models
help us to gain understandings of scientific phenomena.
2. CHARACTERISTIC: A distinguishing physical feature or behavioral condition in a living organism—for example, “eye color” “ability to roll tongue or
not.”
3. TRAIT: A particular version of a characteristic that is determined by one or more genes—for example, “blue eyes.”
4. INHERITANCE: The process by which traits or characteristics pass from parents to their offspring. One half of each parents’ genes (that
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determine which traits get expressed) are randomly selected to be within the reproductive cells of sperm and eggs. As a result, offspring
receive one half of their genes from each parent.
GENES: A segment of DNA, on a chromosome, which provides the inherited bits of information passed down from parent’s cells to the
offspring’s cells. Genes are responsible for determining all inherited traits.
GENETICS: A branch of biology that studies heredity and the variation of inherited traits among related organisms.
OFFSPRING: The term used when referring to non-human organisms instead of “children.” Only humans have children.
PEDIGREE: A family tree used for genetic analysis. Researchers use pedigrees to look for patterns of inheritance from one generation to the
next.
DOMINANT GENE (ALLELE): If an organism inherits a “dominant” allele (for a trait), from either parent, then it will be that form of the gene that gets
expressed because the dominant genes will suppress others that are called “recessive” genes.
RECESSIVE GENE (ALLELE): The version or form of a gene that does not get expressed as an offspring’s trait unless two such genes are
inherited--one from each parent.
ALLELE: Simply put, an allele is a version or form of a gene that determines which traits get expressed or appear in an organism.
HOMOZYGOUS / PURBRED: (AKA Purebred) An organism with identical alleles for a characteristic is homozygous.
HETEROZYGOUS / HYBRID: (AKA Hybrid) An organism with different pairs of alleles for a characteristic is heterozygous.
ASEXUAL REPRODUCTION: Reproduction of offspring in which it is not necessary to have two parents. The offspring are considered clones of the
parent. Reproduction may involve “cell-splitting,” “budding,” and “artificial cloning.”
SEXUAL REPRODUCTION: Reproduction of offspring that requires the union of two sex cells produced by two parents. Sexual reproduction
produces offspring that show a combination of traits inherited from both parents.
MUTATION: A random change in the genes or chromosomes of an organism. Most mutations have harmful effects, but some can increase an
organism’s ability to survive. Mutations occurring in reproductive cells can be passed from generation to the next.
PHENOTYPE: The visible trait/physical appearance displayed by an organism that is determined by the set alleles (genotype) inherited as well as
environmental factors.
GENOTYPE: A particular set of alleles inherited by an organism.
ZYGOTE: Once the male reproductive cell, called a sperm cell, joins together with the female reproductive cell, called an egg cell, fertilization
occurs and the fertilized egg is now called a zygote.
CHROMOSOME: A structure in all living cells, which carries the genes that determine heredity.
DNA: Short for “deoxyribonucleic acid.” DNA exists mainly in the nucleus of each cell of a living organism, and it consists of two long strands
linked together in a structure resembling a ladder twisted into a spiral, called a “double helix.”
NATURE VS. NURTURE: These terms refer to traits being a result of either genetic inheritance (nature), environmental factors (nurture), or both.
For example, the color of grass is typically green because of its genetic “nature,” but when a section of it gets covered, blocking exposure to
sunlight, it changes to a shade of pale yellow due to environmental factors or “nurture.”
INCOMPLETE DOMINANCE: When offspring receive traits that appear to be a blending of the parents’ traits, this is said to be incomplete
dominance. For example, in some plants, a cross between a red-flowered and white-flowered plant will give pink-flowered offspring.
CO-DOMINANCE: When offspring inherit both traits from its parents, we call this co-dominance. For example, in humans, a person with type A
blood and a person with type B blood can have a child with type AB blood.
CARRIER: A person who is heterozygous (a hybrid) for a recessive genetic condition. They carry the gene, but don’t have the genetic trait.
DNA FINGERPRINTING: (AKA: Genetic Fingerprinting or Genetic Profiling)—DNA fingerprinting uses technology and a sample of DNA to
accurately distinguish one person from another (with the exception of identical twins). This technology can be used to determine if people are
related; to link suspects to crimes; and to identify unknown/unrecognizable human remains.