Key words #3 Flashcards
Deoxyribonucleic acid
The chemical composition of the molecules that contain the genes, which are the chemical instructions for cells to manufacture various proteins.
Chromosome
One of the 46 molecules of DNA (in 23 pairs) that virtually each cell of the human body contains and that, together, contain all the gene. Other species have more or fewer chromosomes.
Gamete
A reproductive cell. In humans it is a sperm or an ovum
Zygote
The single cell formed from the union of two gametes, a sperm, and an ovum
Gene
A small section of a chromosome; the basic unit for the transmission of heredity. A gene consists of a string of chemicals that provide instructions for the cell to manufacture certain proteins
Allele
A variation that makes a gene different in some way from other genes for the same characteristics. Many genes never vary; others have several possible alleles
Genome
The full set of genes that are the instructions to make an individual member of a certain species
Copy number variations
Genes with various repeats or deletions of base pairs
Autosomes
The chromosomes that are not sex chromosomes that is, not the 23rd pair. Humans usually have 44 autosomes
Homozygous
Referring to two genes of one pair that are exactly the same in every letter of their code. Most genes pairs are homozygous
Heterozygous
Referring to two genes of one pair that differ in some way. Typically, one allele has only a few base pairs that differ from the other member of the pair
23rd pair
The chromosome pair that, in humans, determines sex. The other 22 pairs are autosomes, inherited equally by males and females
XY
A 23rd chromosome pair that consists of an X-shaped chromosome from the mother and a Y-shaped chromosome from the father. XY zygotes become males
XX
A 23rd chromosome pair that consists of two X-shaped chromosomes, one each from the mother and father. XX zygotes become females.
Epigenetics
The study of how environmental factors affect genes and genetic expression - enhancing, halting shaping, or altering the expression of genes.
Microbiome
All the microbes (bacteria, viruses, and son on) with all of their genes in a community
In vitro fertilization
Fertilization that takes place outside a woman’s body (as in a glass laboratory dish). The procedure involves adding sperm to ova that have been surgically removed from the woman’s ovary. If a zygote is produced, it is inserted into a woman’s uterus, where it may implant and develop into a baby
Stem cells
Cells from which any other specialized type of cell can form
Golden rice
A variant of rice that has been genetically modified to contain vitamin A, thus preventing blindness. This GMO rice is yellowish in color, hence the name.
Monozygotic (MZ twins)
Twins who originate from one zygote that splits apart very early in development (also called identical twins.) Other monozygotic multiple births (such as triplets and quadruplets) can occur as well.
Dizygotic (DZ) twins
Twins, who are formed when two separate ova are fertilized by two separate sperm at roughly like the same time (Also called fraternal twins).
Phenotype
Is the observable characteristics of a person, including appearance, personality, intelligence, and all other traits.
Genotype
A person’s entire genetic inheritance, or genetic potential.
Dominant
Reflected in the phenotype. Dominant genes have more influence on traits than recessive genes.
Human Genome Project
Is an international effort to map the complete human genetic code. This effort was essentially completed in 2001, though analysis is ongoing.
Recessive
Hidden, not dominant. Recessive genes are carried in the genotype and are not evident in the phenotype, except in special circumstances.
Carrier
A person whose genotype includes a gene that is not expressed in the phenotype. The carried gene occurs in half of the carrier’s gametes and thus is passed on to half of the carrier’s children. If such a gene is inherited from both parents, the characteristic appears in the phenotype
