Prenatal development Chapter 2 Exam
Questions With 100% Correct Answers
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What is the difference between monozygotic and dizygotic twins? - Answer-
Monozygotic twins are genetically identical (one zygote splits), while dizygotic twins are
non-identical (two separate ova fertilized by two separate sperm).
Which parent's gamete determines the sex of the child? - Answer- The father's sperm,
as it can carry either an X or a Y chromosome.
Define genotype versus phenotype. - Answer- Genotype is the underlying combination
of genetic material (DNA), while phenotype is the set of observable traits.
What does it mean to be homozygous versus heterozygous for a trait? - Answer-
Homozygous means receiving the same alleles from both parents; heterozygous means
receiving different alleles.
What is the basic unit of genetic information? - Answer- Genes
How many pairs of chromosomes are in a typical human cell? - Answer- 23 pairs (46
total)
What is the process of cell replication called? - Answer- Mitosis
Which process is responsible for the formation of gametes (ovum and sperm)? -
Answer- Meiosis
What are polygenic traits? - Answer- Traits whose inheritance or phenotype is controlled
by multiple gene pairs, such as skin color.
Why are males at a higher risk for X-linked disorders? - Answer- Because they have
only one X chromosome (XY), meaning they lack a second X chromosome to potentially
mask a recessive disorder.
What is the chromosomal cause of Down syndrome? - Answer- An extra chromosome
on the 21st pair (trisomy).
What are the characteristics of Klinefelter's syndrome? - Answer- An extra X
chromosome in males (XXY), leading to under-developed genitals and both male and
female physical changes.
, What is Turner's syndrome? - Answer- A condition in females where one X
chromosome is missing (X0), resulting in stunted growth and the inability to menstruate
or develop breasts at puberty.
Define multifactorial transmission. - Answer- The process where traits are determined
by a combination of both genetic and environmental factors.
How do twin studies help researchers distinguish between genetic and environmental
influences? - Answer- By comparing identical twins raised in different environments and
fraternal twins raised in the same environment, researchers can isolate the relative
impact of biology versus environment.
What is the 'reaction range' in genetics? - Answer- The degree of variability in the
expression of a trait depending on the environment.
How can a child's genetics influence their environment? - Answer- Children may choose
environments that suit their genetic abilities, evoke specific responses from parents, or
parents may provide opportunities based on their own genetic predispositions.
What is the result of fertilization? - Answer- The fusion of a sperm and an ovum to form
a new cell called a zygote.
Where does fertilization typically occur? - Answer- In the fallopian tubes.
What is Fragile X syndrome? - Answer- A genetic disorder caused by an injury to a
gene on the X chromosome, resulting in mild to moderate intellectual disabilities.
What is the primary cause of the increase in multiple births since the 1980s? - Answer-
The increased use of fertility drugs, rising maternal age, and assisted human
reproduction.
What is the difference between a dominant and recessive trait? - Answer- A dominant
trait is expressed when present; a recessive trait is only expressed if the individual is
homozygous for that trait.
What percentage of the human genetic sequence is shared among all humans? -
Answer- 99.9%.
What is the role of the dopamine gene in personality? - Answer- It is associated with
risk-taking behaviors.
What is the duration of the germinal stage of prenatal development? - Answer- 0 to 2
weeks.
At what point does a zygote become a blastocyst? - Answer- After approximately 32 cell
divisions (about 3 days).
Questions With 100% Correct Answers
| Verified | Latest Update
What is the difference between monozygotic and dizygotic twins? - Answer-
Monozygotic twins are genetically identical (one zygote splits), while dizygotic twins are
non-identical (two separate ova fertilized by two separate sperm).
Which parent's gamete determines the sex of the child? - Answer- The father's sperm,
as it can carry either an X or a Y chromosome.
Define genotype versus phenotype. - Answer- Genotype is the underlying combination
of genetic material (DNA), while phenotype is the set of observable traits.
What does it mean to be homozygous versus heterozygous for a trait? - Answer-
Homozygous means receiving the same alleles from both parents; heterozygous means
receiving different alleles.
What is the basic unit of genetic information? - Answer- Genes
How many pairs of chromosomes are in a typical human cell? - Answer- 23 pairs (46
total)
What is the process of cell replication called? - Answer- Mitosis
Which process is responsible for the formation of gametes (ovum and sperm)? -
Answer- Meiosis
What are polygenic traits? - Answer- Traits whose inheritance or phenotype is controlled
by multiple gene pairs, such as skin color.
Why are males at a higher risk for X-linked disorders? - Answer- Because they have
only one X chromosome (XY), meaning they lack a second X chromosome to potentially
mask a recessive disorder.
What is the chromosomal cause of Down syndrome? - Answer- An extra chromosome
on the 21st pair (trisomy).
What are the characteristics of Klinefelter's syndrome? - Answer- An extra X
chromosome in males (XXY), leading to under-developed genitals and both male and
female physical changes.
, What is Turner's syndrome? - Answer- A condition in females where one X
chromosome is missing (X0), resulting in stunted growth and the inability to menstruate
or develop breasts at puberty.
Define multifactorial transmission. - Answer- The process where traits are determined
by a combination of both genetic and environmental factors.
How do twin studies help researchers distinguish between genetic and environmental
influences? - Answer- By comparing identical twins raised in different environments and
fraternal twins raised in the same environment, researchers can isolate the relative
impact of biology versus environment.
What is the 'reaction range' in genetics? - Answer- The degree of variability in the
expression of a trait depending on the environment.
How can a child's genetics influence their environment? - Answer- Children may choose
environments that suit their genetic abilities, evoke specific responses from parents, or
parents may provide opportunities based on their own genetic predispositions.
What is the result of fertilization? - Answer- The fusion of a sperm and an ovum to form
a new cell called a zygote.
Where does fertilization typically occur? - Answer- In the fallopian tubes.
What is Fragile X syndrome? - Answer- A genetic disorder caused by an injury to a
gene on the X chromosome, resulting in mild to moderate intellectual disabilities.
What is the primary cause of the increase in multiple births since the 1980s? - Answer-
The increased use of fertility drugs, rising maternal age, and assisted human
reproduction.
What is the difference between a dominant and recessive trait? - Answer- A dominant
trait is expressed when present; a recessive trait is only expressed if the individual is
homozygous for that trait.
What percentage of the human genetic sequence is shared among all humans? -
Answer- 99.9%.
What is the role of the dopamine gene in personality? - Answer- It is associated with
risk-taking behaviors.
What is the duration of the germinal stage of prenatal development? - Answer- 0 to 2
weeks.
At what point does a zygote become a blastocyst? - Answer- After approximately 32 cell
divisions (about 3 days).
