Biology B Final Review
What are alleles? How many alleles does an individual have for one particular trait? - correct answer -
Alternative from of one gene. There are two alleles per trait.
What are the sources of genetic variation in asexual and sexual organisms? - correct answer -1.
Mutations
2. Random Fertilization
3. Independent Assortment
4. Crossing Over
What is the principle of independent assortment? - correct answer -Formation of random combinations
of chromosomes in meiosis.
A bird homozygous for black feathers and a bird homozygous for white feathers and 100% of the
offspring have black and white feathers. What is this called? - correct answer -Codominance, both the
black and white trait is expressed.
A bird homozygous for black feathers and a bird homozygous for white feathers and 100% of the
offspring have gray feathers. What is this called? - correct answer -Incomplete dominance, the traits
have blended together.
In rabbits, coat color is determined by multiple alleles. What does this mean? - correct answer -Gene
pairing has an effect on the phenotype.
Pleiotropy- one trait is determined by multiple alleles.
What are linked genes? Do they assort independently or dependently? - correct answer -They are genes
that are located on the same chromosome and are inherited together therefore they are assorted
dependently.
, How many chromosomes are found in humans? How many pairs? - correct answer -Humans have 46
chromosomes and 23 homologous pairs.
What is a karyotype? How can karyotypes be used to diagnose some disorders? - correct answer -A
visual representation of the chromosomes in your body. They can help you see mutations and
abnormalities.
Which chromosomes are autosomes? Which are sex chromosomes? - correct answer -Pairs 1-22 are
autosomes and pair 23 are sex chromosomes.
What chromosomes would you expect to find in a female? Male? - correct answer -Female: xx
Male: xy
What are the three effects of mutations on an organism's phenotype? - correct answer -Good, bad, none
Mutations cannot be passed on from parent to offspring when mutations occur in gametes or somatic
cells? - correct answer -Somatic cells
What is meant by a sex-linked trait? Under what conditions would a person exhibit a sex-linked
disorder? - correct answer -Gene carried by a gamete. Disorders from mutations in the gametes.
What are some examples of sex-linked traits? - correct answer -Color blindness and male pattern
baldness
The ABO blood group is determined by multiple alleles. How many alleles are involved? How many can a
normal individual carry? List the possible genotypes. - correct answer -3 alleles involved, normal
individual can carry 2
AA, BB, OO, AO, BO, AB
In humans, polygenic traits are common. What are polygenic traits and what is an example? - correct
answer -Multiple physical traits from one allele. Hair color, height, skin color
What are alleles? How many alleles does an individual have for one particular trait? - correct answer -
Alternative from of one gene. There are two alleles per trait.
What are the sources of genetic variation in asexual and sexual organisms? - correct answer -1.
Mutations
2. Random Fertilization
3. Independent Assortment
4. Crossing Over
What is the principle of independent assortment? - correct answer -Formation of random combinations
of chromosomes in meiosis.
A bird homozygous for black feathers and a bird homozygous for white feathers and 100% of the
offspring have black and white feathers. What is this called? - correct answer -Codominance, both the
black and white trait is expressed.
A bird homozygous for black feathers and a bird homozygous for white feathers and 100% of the
offspring have gray feathers. What is this called? - correct answer -Incomplete dominance, the traits
have blended together.
In rabbits, coat color is determined by multiple alleles. What does this mean? - correct answer -Gene
pairing has an effect on the phenotype.
Pleiotropy- one trait is determined by multiple alleles.
What are linked genes? Do they assort independently or dependently? - correct answer -They are genes
that are located on the same chromosome and are inherited together therefore they are assorted
dependently.
, How many chromosomes are found in humans? How many pairs? - correct answer -Humans have 46
chromosomes and 23 homologous pairs.
What is a karyotype? How can karyotypes be used to diagnose some disorders? - correct answer -A
visual representation of the chromosomes in your body. They can help you see mutations and
abnormalities.
Which chromosomes are autosomes? Which are sex chromosomes? - correct answer -Pairs 1-22 are
autosomes and pair 23 are sex chromosomes.
What chromosomes would you expect to find in a female? Male? - correct answer -Female: xx
Male: xy
What are the three effects of mutations on an organism's phenotype? - correct answer -Good, bad, none
Mutations cannot be passed on from parent to offspring when mutations occur in gametes or somatic
cells? - correct answer -Somatic cells
What is meant by a sex-linked trait? Under what conditions would a person exhibit a sex-linked
disorder? - correct answer -Gene carried by a gamete. Disorders from mutations in the gametes.
What are some examples of sex-linked traits? - correct answer -Color blindness and male pattern
baldness
The ABO blood group is determined by multiple alleles. How many alleles are involved? How many can a
normal individual carry? List the possible genotypes. - correct answer -3 alleles involved, normal
individual can carry 2
AA, BB, OO, AO, BO, AB
In humans, polygenic traits are common. What are polygenic traits and what is an example? - correct
answer -Multiple physical traits from one allele. Hair color, height, skin color
