25 terms
Genetics, DNA, and Mutations
Genotype
An organism's genetic code, or allele combinations. Represented by letters
Phenotype
An organism's physical appearance, or visible traits.
Trait
A characteristic that an organism can pass on to its offspring through its genes.
Allele
Different forms of a gene
Heterozygous
An organism that has two different alleles for a trait, ex. Gg
Homozygous
An organism that has two identical alleles for a trait, ex. GG or gg
Dominant
Describes a trait that covers over, or dominates, another form of that trait.
Recessive
An allele that is masked when a dominant allele is present
Gene
A segment of DNA on a chromosome that codes for a specific trait
DNA
deoxyribonucleic acid, holds specific code for your body
Nucleotide
A building block of DNA, consisting of a five-carbon sugar, a nitrogenous base, and a phosphate group.
Nitrogenous bases in DNA
adenine, guanine, cytosine, thymine
Adenine (A) pairs with
Thymine (T)
Cytosine (C) pairs with
Guanine (G)
amino acids
building blocks of proteins
Proteins
Chains of amino acids, allow the body to perform and function
DNA replication
the process of making a copy of DNA, final result is 2 identical daughter strands
Chromosomes
rod-shaped structures that contain all basic hereditary information
Humans have ___ pairs of chromosomes
23
Humans have ___ chromosomes
46
deletion mutation
a mutation in which one or more pairs of nucleotides are removed from a gene
substitution mutation
a mutation in which one nitrogeneous base (nucleotide) is changed to another
insertion mutation
a mutation in which one or more nucleotides are added to a gene
frameshift mutation
involves the insertion or deletion of a nucleotide in the DNA sequence, cause s the "reading" of the genetic message to be shifted
codon
a sequence of three nucleotides that code for an amino acid