Mechanism of Heredity Flashcards
The “stuff” of heredity is a chemical
deoxyribonucleic acid (DNA)
Chemical that carries inherited instructions
for the development of all cellular forms of
life
deoxyribonucleic acid (DNA)
The double-helix structure of a DNA
molecule resembles a long, spiraling ladder whose steps are made of pairs of chemical units
Bases
The 4 Bases
Adenine, thymine, cytosine, and guanine.
Sequence of bases within the DNA
molecule; governs the formation of proteins
that determine the structure and functions of
living cells
Genetic Code
Coils of DNA that consist of gene
chromosomes
Small segments of DNA located in definite
positions on particular chromosomes; functional units of heredity.
Genes
Complete sequence of genes in the human body.
Human genome
Permanent alterations in genes or chromosomes that may produce harmful
characteristics.
Mutations
In humans, the 22 pairs of chromosomes
not related to sexual expression
Autosomes
Pair of chromosomes that determines sex:
XX in the normal human female, XY in the
normal human male
Sex chromosomes
The,Y chromosome contains the gene for maleness
SRY GENE
Genes that can produce alternative
expressions of a characteristic (such as the
presence or absence of dimples).
Alleles
for the characteristic - both alleles are the same
Homozygous
when they are different
Heterogygous
