genes Flashcards
A functional
hereditary unit made up
of DNA that occupies a
fixed location on a
chromosome.
Gene
Humans have
approximately ____________ proein-encoding
genes
20,000 -25,000
four biochemicals known as bases or nucleotides:
adenine (A), cytosine (C), guanine (G), and thymine (T)
it is entire set of DNA instructions found in a
cell.
Genome
In humans, the genome consists of ___ pairs
of chromosomes
23
The genetic composition of an
individual organism
Genotype
The observable appearance of
an individual organism.
Phenotype
The translation of the
genotype into the
phenotype of an
organism.
Gene Expression
An _____ is one of two or more
versions of DNA sequence (a single
base or a segment of bases) at a
given genomic location.
allele
- Having two identical alleles for a
given gene.
Homozygous
- Having two different alleles for a
given gene.
Heterozygous
- A gene that will produce its
characteristic phenotype only when it occurs in
a homozygous pair.
Recessive allele
-A gene that produces its
phenotype regardless of whether it occurs in a
heterozygous or homozygous pair.
Dominant allele
It is a type of cell division in sexually
reproducing organisms that reduces the number
of chromosomes in gametes (the sex cells, or egg
and sperm).
Meiosis
Crossing over is a cellular
process that happens during meiosis when
chromosomes of the same type are lined up.
Crossing over