General Biology Final Exam
Review Questions and Answers
Homologous - -term used to describe pairs of chromosomes having DNA
segments, or genes for the same traits
-What is the organization of genetic information within a cell nucleus? - -
Genes--> Chromosomes-->Nucleus
-If Yellow is dominant to Green in pea plants and a plant exhibits the yellow
phenotype, what are the possible genotypes? - -Yy or YY
-Which cells are considered gametes in humans? - -Egg (Ova) in females;
Sperm in males
-What is the number of chromosomes found in normal human gametes? - -
23 chromosomes
-What is Mendel's Law of Independent Assortment? - -Factors for different
traits are inherited independently of one another.
-What is the expected phenotypic ratio in any dihybrid cross? - -9-3-3-1 or
(9/16:3/16:3/16:1/16)
9: Dominant-Dominant
3: Dominant-Recessive
3: Recessive-Dominant
1: Recessive Recessive
-What do the boxes found in a punnett square represent? - -Potential
genotypes for the offspring.
-Crossing Over - -What process is shown in the illustration provided?
-Why is meiosis significant in helping to maintain the continuation of a
species? - -It provides for chromosomal variation in the gametes produced
by an organism.
-If Snapdragon's exhibit incomplete dominance. What would the
PHENOTYPIC ratio be of a white plant crossed with a pink plant? - -1: 1
(White to pink, no red plants will result)
-What are the possible gametes for a parent who is BbTt? - -BT, Bt, bT, tb
, -What is Mendel's Law of Segregation? - -2 alleles separate during formation
of gametes
-What would the sex chromosomes look like for a normal human female? - -
XX
-What would the sex chromosomes look like for a normal human male? - -XY
-Which sex chromosome is found in female gametes? - -X
-Who determines the sex in humans? - -Male
-Tall is dominant to short in pea plants. When crossing two tall plants, 1/4 of
them turned out short. What is the genotype of the parents? - -Both are Tt
(heterozygous)
-It must be a dominant trait since one of the parents is unaffected and yet
there are offspring who are affected. The unaffected parent must be
heterozygous for the condition. - -By observing the pedigree to the right,
and assuming that shapes that are shaded are affected. What can you
determine with regard to this trait?
-What would be one indicator for a trait being sex-linked in a pedigree
diagram? - -Only males are affected in the diagram.
-What genetic characteristic did we examine in class that demonstrates the
principle of codominance? - -Human Blood Type
-What is sickle cell anemia? - -A co-dominant genetic disorder where the
shape of the red cells are sickle shaped. In the diagram, this person is a
heterozygote because only 1/2 of their cells are affected.
-What are some examples of diseases that we studied in class that resulted
from non-disjunction? - -Trisomy 21 (Down's Syndrome)
Trisomy 13
etc.
-What is nondisjunction? - -Chromosomes divide unevenly during meiosis,
leads to chromosome abnormalities
-What type of trait is colorblindness and how do you know? - -It is sex-linked
and is carried on the X chromosome. Males are more often affected than
females.
-If a female is normal, but has a colorblind son, what do you know about her
genotype? - -She must be a carrier (heterozygous) for the condition.
Review Questions and Answers
Homologous - -term used to describe pairs of chromosomes having DNA
segments, or genes for the same traits
-What is the organization of genetic information within a cell nucleus? - -
Genes--> Chromosomes-->Nucleus
-If Yellow is dominant to Green in pea plants and a plant exhibits the yellow
phenotype, what are the possible genotypes? - -Yy or YY
-Which cells are considered gametes in humans? - -Egg (Ova) in females;
Sperm in males
-What is the number of chromosomes found in normal human gametes? - -
23 chromosomes
-What is Mendel's Law of Independent Assortment? - -Factors for different
traits are inherited independently of one another.
-What is the expected phenotypic ratio in any dihybrid cross? - -9-3-3-1 or
(9/16:3/16:3/16:1/16)
9: Dominant-Dominant
3: Dominant-Recessive
3: Recessive-Dominant
1: Recessive Recessive
-What do the boxes found in a punnett square represent? - -Potential
genotypes for the offspring.
-Crossing Over - -What process is shown in the illustration provided?
-Why is meiosis significant in helping to maintain the continuation of a
species? - -It provides for chromosomal variation in the gametes produced
by an organism.
-If Snapdragon's exhibit incomplete dominance. What would the
PHENOTYPIC ratio be of a white plant crossed with a pink plant? - -1: 1
(White to pink, no red plants will result)
-What are the possible gametes for a parent who is BbTt? - -BT, Bt, bT, tb
, -What is Mendel's Law of Segregation? - -2 alleles separate during formation
of gametes
-What would the sex chromosomes look like for a normal human female? - -
XX
-What would the sex chromosomes look like for a normal human male? - -XY
-Which sex chromosome is found in female gametes? - -X
-Who determines the sex in humans? - -Male
-Tall is dominant to short in pea plants. When crossing two tall plants, 1/4 of
them turned out short. What is the genotype of the parents? - -Both are Tt
(heterozygous)
-It must be a dominant trait since one of the parents is unaffected and yet
there are offspring who are affected. The unaffected parent must be
heterozygous for the condition. - -By observing the pedigree to the right,
and assuming that shapes that are shaded are affected. What can you
determine with regard to this trait?
-What would be one indicator for a trait being sex-linked in a pedigree
diagram? - -Only males are affected in the diagram.
-What genetic characteristic did we examine in class that demonstrates the
principle of codominance? - -Human Blood Type
-What is sickle cell anemia? - -A co-dominant genetic disorder where the
shape of the red cells are sickle shaped. In the diagram, this person is a
heterozygote because only 1/2 of their cells are affected.
-What are some examples of diseases that we studied in class that resulted
from non-disjunction? - -Trisomy 21 (Down's Syndrome)
Trisomy 13
etc.
-What is nondisjunction? - -Chromosomes divide unevenly during meiosis,
leads to chromosome abnormalities
-What type of trait is colorblindness and how do you know? - -It is sex-linked
and is carried on the X chromosome. Males are more often affected than
females.
-If a female is normal, but has a colorblind son, what do you know about her
genotype? - -She must be a carrier (heterozygous) for the condition.
