Reproduction and Genetics Notes
Reproduction
Asexual
1 parent
Clone-No Genetic
variation
Advantages
1 parent – does not
have to find a mate
Disadvantages
No genetic variation –
species can be wiped
out due to
environmental
changes/disease
Genes and Traits
Sexual
2 parents
Genetic Variationdifferences
Genetic variation –
reduces chances of
complete loss of
species due to
disease/change in
environment
Bacteria
Archaebacteria
Eukaryote
Genetic material is
contained in a nucleus
Animals
Plants
Fungi
Protists

Humans have 46 chromosomes
Other organisms have different amounts
Genetic material is called DNA
A gene contains information about a specific trait
Genes occur in pairs
o Alleles are a form of a gene and occurs in pairs (2) which can
be dominant or recessive
Independent Assortment
o Every trait has 2 alleles
o This pair of alleles from each parent separates and the
offspring will only inherit one allele from each parent.
Law of Dominance
o Heredity information for two different forms of a trait can
coexist in one individual
o One form of the trait masks the expression of the other
Dominant


If a dominant allele is present, the dominant trait will appear in an
organism.
Represented by capital letter
Recessive


DNA




2 parents – individuals
have to find mates.
Cells
Prokaryote
Genetic material is NOT
contained in a nucleus


In order for a recessive trait to appear, both alleles must be
recessive.
Represented by a lower case letter
Organization of Genetic Material
DNA
Gene
Chromosome
Cell Nucleus
Reproduction and Genetics Notes
Vocabulary
Gene
Allele
Dominant
Recessive
Phenotype
Genotype
Heterozygous
Homozygous
Heredity
Chromosomes
Basic unit of heredity
One of two alternate forms of a gene
An allele whose trait always shows up in the organism
when it is present
An allele that is masked/covered up when a dominant
allele is present
Physical characteristics – what is seen
Set of alleles (ex: bb) – allele combination
A combination of alleles that are different
A combination of alleles that are the same
the passage of genetic instructions from one
generation to the next
found INSIDE the nucleus/A structure in all living cells
that consists of a single molecule of DNA bonded to
various proteins and that carries the genes
determining heredity.