Genetics Flashcards
Genetics
the study of heredity and the variation of inherited characteristics.
Heredity
the passing on of physical or mental characteristics genetically from one generation to another.
Inheritance
a thing that is inherited.
Dominant
An allele or a gene that is expressed in an organism’s phenotype, masking the effect of the recessive allele or gene when present.
Recessive
A recessive gene is a gene that can be masked by a dominant gene. … You might remember the word recessive from biology, where it most often appears. Its opposite is dominant and is always living in its shadow. A recessive allele has to team up with another recessive allele in order to show up.
Allele
An allele is one of the possible forms of a gene. Most genes have two alleles, a dominant allele and a recessive allele. If an organism is heterozygous for that trait, or possesses one of each allele, then the dominant trait is expressed. … Alleles were first defined by Gregor Mendel in the law of segregation.
Mitosis
A process in which the parent cell divides itself into 2 identical daughter cells containing the same DNA information
Deoxyribonucleic acid (DNA)
Deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information
Nucleotide
a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.
deoxyribose
a sugar derived from ribose by replacement of a hydroxyl group by hydrogen.
adenine (A)
a compound which is one of the four constituent bases of nucleic acids. A purine derivative, it is paired with thymine in double-stranded DNA.
thymine (T)
a compound which is one of the four constituent bases of nucleic acids. A pyrimidine derivative, it is paired with adenine in double-stranded DNA.
guanine (G)
a compound that occurs in guano and fish scales, and is one of the four constituent bases of nucleic acids. A pure derivative, it is paired with cytosine in double-stranded DNA.
cytosine (C)
a compound found in living tissue as a constituent base of DNA. It is paired with guanine in double-stranded DNA.
base pairing
Any of the pairs of nucleotides connecting the complementary strands of a molecule of DNA or RNA and consisting of a purine linked to a pyrimidine by hydrogen bonds. The base pairs are adenine-thymine and guanine-cytosine in DNA, and adenine-uracil and guanine-cytosine in RNA or in hybrid DNA-RNA pairing
Chargaff’s rule .
Chargaff’s rules state that DNA from any cell of any organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine. This pattern is found in both strands of the DNA.
nucleic acids
a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.
nitrogenous base
A nitrogenous base is simply a nitrogen-containing molecule that has the same chemical properties as a base. They are particularly important since they make up the building blocks of DNA and RNA: adenine, guanine, cytosine, thymine and uracil.
double helix
a pair of parallel helices intertwined about a common axis, especially that in the structure of the DNA molecule.
complementary base pairs
Complementary base pairing is the phenomenon where in DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine.
amino acid
a simple organic compound containing both a carboxyl (—COOH) and an amino (—NH2) group.
ribose
a sugar of the pentose class which occurs widely in nature as a constituent of nucleosides and several vitamins and enzymes.
uracil
a compound found in living tissue as a constituent base of RNA. In DNA it is replaced by thymine.
codon
a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.
