Chapter 14 Flashcards
What does homozygous mean?
describes an individual with two alleles at one
locus that are identical (two dominant or recessive alleles for one
trait) (homo = same)
What does heterozygous mean?
describes an individual with two different alleles
at a locus (one dominant and one recessive allele for a single
traits)
What is a genotype?
genetic makeup of an organism; remains constant
throughout an individual’s life. Usually indicated by the
combination of letters in a Punnett square
What is a phenotype?
the physical and physiological traits of an organism
what is an allele
An alternate form of a gene
why was the pea plant a great choice for Mendels experiments?
1) They were easy to get!
2) They are easy to grow and mature quickly!
3) The pea plant has enclosed reproductive organs, so Mendel could manipulate which plants he bred. This allowed for more reliable experiments + results!
4) They’re single plants - They only have 2 variations for each trait that could easily be observed + reported.
ex: Tall or short
What were Gregor Mendel’s established 3 main laws?
1) Law of dominance
2) Law of segregation
3) Law of independent assortment
What is the law of segregation?
Mendel’s first
law of inheritance, in which the
hereditary traits are determined by the
pair of alleles from each parent. These
alleles are separated during gamete
formation, giving each offspring only
one allele from each parent.
what is the universal blood donor?
O
What is the universal reciever?
AB
what is a dominant trait?
a characteristic which is always expressed or
always appears in an individual.
what is a recessive trait?
a characteristic which is latent or inactive and
usually does not appear in an individual.
what is the law of independent assortment?
Mendel’s second law of inheritance,
stating that the inheritance of alleles
for one trait does not affect the
inheritance of alleles for another trait.
cross of an individual
with unknown genotype with a
homozygous recessive individual;
used as a method to identify an
unknown genotype.
Ex. Suppose you had an unknown tall
pea plant. You could breed it with a
short plant and see the ratios of the
offspring produced.
Test cross
