Download Meiosis and Genetics

Nicholas Olofsson and Elissa Harris
Period 3
Meiosis
 Process that converts diploid
nuclei into haploid nuclei
 Occurs in the sex organs-testes
and ovaries
 Produces gametes- sperm and
eggs
 Divided into Meiosis 1 and
Meiosis 2
Meiosis 1
 Cell division that reduces the chromosome
number by half
Meiosis 2
 No interphase 2 and similar to
mitosis
Questions:
 What is one advantage and disadvantage of asexual reproduction?
 What is one advantage and disadvantage of sexual reproduction?
 How does meiosis ensure genetic diversity?
 When does independent assortment and crossing over occur during
meiosis?
 List three ways mitosis and meiosis are similar.
 List three ways mitosis and meiosis are different.
Genetics
 The study of heredity or how
traits are passed for parents to
offspring
 Traits are distinguishing
qualities pr characteristics
Mendel’s Laws
 Law of Segregation
 Two members of a gene pair
separate from each other in the
formation of gametes
 Half the gametes carry one allele
and the others carry the other
 Law of Dominance
 The trait that shows in a
heterozygous individual is
dominant and the hidden trait is
recessive
 Law of Independent Assortment
 A particular allele for one trait
can be paired with either allele
of another trait
Exceptions
 Incomplete Dominance
 Heterozygous alleles have a
phenotype that is in between
two homozygotes
 Codominance
 When both alleles are fully
expressed usually in a pattern
Punnet Squares
 Diagram used to predict
outcome of genetic cross
 Phenotype: observable trait
 Genotype: combination of
alleles
Pedigrees and Karyotypes
Pedigree: recorded ancestry of a person
or family
Karyotype: organized profile of
a person’s chromosomes
Questions:
 The outward appearance (gene
expression) of a trait in an
organism is referred to as:
 A. genotype
B. phenotype
C. an allele
D. independent assortment
 What is the ratio for a dihybrid
cross between parents that are
heterozygous for both traits?
 The mating of two curly-haired
brown guinea pigs results in some
offspring with brown curly hair,
some with brown straight hair, some
with white curly hair, and even some
with white straight hair. This
mating illustrates which of Mendel's
Laws?
 A. Dominance
B. Segregation
C. Independent Assortment
D. Sex-Linkage