Ch 1 Vocab (Exam 1) Flashcards
CRISPR-Cas
Molecular mechanism found in bacteria that has the potential to revolutionize our ability to rewrite the DNA sequence of genes from any organism.
Epigenesis
Theory that an organism develops from the fertilized egg by a succession of developmental events that eventually transform the egg into an adult.
Preformationism
Theory that the fertilized egg contains a complete miniature adult called a homunculus.
Cell Theory
States all organisms are composed of basic structural units called cells, which are derived from preexisting cells.
Spontaneous generation
The creation of living organisms from non living components (disproved by Louis Pasteur later in the 19th century).
Natural selection
Theory that presented an explanation of the mechanism of evolutionary change etc.
Genetics
Branch of biology concerned with the study of heredity and variation.
Diploid number (2n)
The characteristic number of chromosomes in most eukaryotes (in members of each species).
Homologous chromosomes
Chromosomes in diploid cells exist in these pairs.
Mitosis
A form of cell division. Chromosomes are copied and distributed so that each daughter cell receives a diploid set of chromosomes identical to those in the parental cell.
Meiosis
A form of cell division; associated with gamete formation. Cells produced by this process receive only one chromosome from each chromosome pair.
Haploid number (n)
Cells produced by meiosis receive only one chromosome from each chromosome pair, and the resulting number of chromosomes is called the _______.
Chromosomal theory of inheritance
Theory which states that inherited traits are controlled by genes residing on chromosomes faithfully transmitted through gametes, maintaining genetic continuity from generation to generation.
Mutation
Any heritable change in the DNA sequence and the source of all genetic variation.
