Download HEREDITY AND GENETICS vocabulary terms and

HEREDITY AND GENETICS vocabulary terms and definitions
sexual reproduction
reproduction where half the genetic material is from one parent and half from
another
asexual reproduction
reproduction where parent and offspring are genetically identical
heredity
The passing of genes from parents to offspring
gene
Unit of heredity that occupies a specific location on a chromosome and codes for
the inherited trait
alleles
Pairs of genes that occupy a specific position on a chromosome; genes that code
for the same trait; alternate forms of the same gene
Mendel
Nineteenth century monk that determined the laws of heredity
phenotype
The observable physical characteristics of an organism, determined by genetic
make-up
genotype
The genetic make-up of an organism
dominant allele
a gene that determines the phenotype of a trait
recessive allele
an allele that produces its characteristic phenotype only when its paired allele is
identical
Punnett squares
A mathematical diagram used to calculate the frequencies of different genotypes
and phenotypes among the offspring of a cross
heterozygous
Having different alleles at a particular gene locus on homologous chromosomes
homozygous
Having the same alleles at a particular gene locus on homologous chromosomes
chromosome
A threadlike strand of DNA and proteins that carry the genes
X-chromosome
the sex chromosome associated with female characteristics in mammals
Y-chromosome
the sex chromosome associated with male characteristics in mammals
sex-linked characteristics
A trait that is carried only on the X-chromosome
mitosis
Cell division in somatic cells that produces cells with the same genetic material
(2n) as parent cells
meiosis
Cell division in reproductive cells that produces cells with half the genetic
information (1n) of parent cells
haploid, 1n
Having half the number of chromosomes as a somatic cell; Having a single set of
chromosomes.
diploid, 2n
having pairs of homologous chromosomes
gametes
A reproductive cell having the haploid number of chromosomes; a product of
meiosis
egg
a female gamete
sperm
a male gamete
fertilization
Crossing of gametes from 2 parents
DNA
Molecule that stores information (i.e., the genetic code)
nucleotides
Molecules that line in sequence along the strands of DNA and bond the 2 strands
together
adenine
a nucleotide base that pairs with thymine
thymine
a nucleotide base that pairs with adenine
guanine
a nucleotide base that pairs with cytosine
cytosine
a nucleotide base that pairs with guanine
replication
The copying of DNA before a cell divides
RNA
Translates the genetic code of DNA to make proteins
uracil
an RNA base that substitutes for Thymine
codon
the term geneticists use to describe three base sequences
amino acids
Building blocks of protein; coded by triplets of nucleotide bases
proteins
comprised of amino acids
mutation
a change in DNA
pedigree
Diagram of family relationships
genome
the total genetic content contained in an organism's DNA
selective breeding
intentional breeding of animals or plants having desirable characteristics
genetic engineering
technological alteration of the structure of genetic material in a living organism
clone
A living thing genetically identical to another living thing
somatic cell
Cells in the body which contain a complete copy of an organism’s DNA
embryo
A cluster of cells that are growing and dividing
stem cell
An undifferentiated cell with the ability to divide and to give rise to different
types of specialized cells