Genetics Test Review
1. Know all the vocabulary words!!
2. Compare sexual and asexual reproduction. Sexual reproduction is the type of reproduction where
the genetic material from a sperm and egg cell combine, while asexual reproduction is the type of
reproduction in which one parent produces an offspring without meiosis or fertilization.
3. Compare mitosis and meiosis. Mitosis when a cell divides producing two identical daughter cells,
while meiosis is when a cell divides producing 4 gametes.
4. What are gametes? What is unique about the # of chromosomes in gametes? Gametes are human
reproductive cells. A gamete has half the number of chromosomes as a regular body cell. (ex: human
cells have 46 chromosomes; gametes have 23 chromosomes)
5. What are the male and female gametes called? The male gamete is called a sperm; the female
gamete is called an egg.
6. Compare haploid and diploid cells? Haploid cells have only one chromosome from each
chromosome pair, while a diploid cell has both chromosomes from a chromosome pair.
7. Humans have how may total chromosomes? 46 chromosomes in 23 pairs
8. Compare dominant and recessive alleles. Dominant alleles are traits that are always shown when at
least one allele is present. Recessive alleles are traits that are blocked by a dominant allele and are
only shown when 2 alleles are present.
9. Compare homozygous and heterozygous alleles. Homozygous alleles are alleles that are both
dominant or recessive (HH or hh). Heterozygous alleles are alleles that are mixed (Hh).
10. Compare genotype and phenotype? A genotype is an organism’s complete set of genes. A
phenotype is the physical characteristic shown.
11. Punnett squares – be able to complete them and give ratios of genotypes and phenotypes.
A) One cat carries heterozygous, long-haired traits (Ss), and its mate carries homozygous short-haired
traits (ss) .
S
s
s
s
Ss
ss
Ss
ss
Genotypes: 2 Ss; 2 ss
Phenotypes: 2 long-haired cats; 2 short-haired cats
Genetics Test Review
B) The female dog is heterozygous for spots. The male dog is heterozygous for spots. Having spots is
dominant to no spots. Figure out the phenotypes and genotypes of their possible puppies by using a
Punnett Square.
Female Dog Heterozygous for Spots: Ss
Male Dog Heterozygous for Spots: Ss
S
s
S
SS
Ss
S
Ss
ss
Genotypes: 1 SS, 2 Ss, 1 ss
Phenotypes: 3 dogs with spots, 1 dog without spots