BIO 1050 PRACTICE TEST 2026 TEST BANK
QUESTIONS AND SOLUTIONS ACCURATE
ANSWERS VERIFIED A+
●● What types of cells does meiosis create?
Answer: sperm and eggs
●● What happens if there are errors during meiosis?
Answer: nondisjunctions (ie. disorders like Down Syndrome)
●● Describe meiosis.
Answer: The process that produces haploid gametes in diploid
organisms
●● How many cell divisions occur during meiosis and how many cells
are produced?
Answer: 2 cell divisions
Meiosis 1- homologous pairs separate
Meiosis 2- sister chromatids separate, resulting in 4 haploid cells, each
containing a copy of each chromosome instead of a homologous pair
●● What is a life cycle?
,Answer: Diploid organisms undergo meiosis to create haploid gametes
Sperm fertilizes an egg to create a zygote which undergoes mitosis to
grow
●● What is a zygote?
Answer: a fertilized egg (diploid)
●● Describe the life cycle of a human.
Answer: Meiosis --> Fertilization --> Mitosis
●● What are the male sex chromosomes?
Answer: XY
●● What are the female sex chromosomes?
Answer: XX
●● Explain why fathers determine the sex of their offspring, instead of
mothers.
Answer: Women have 2 X chromosomes, so an X is always present in
every egg (half of eggs get a copy of one X, the other half get the other
X) whereas men have each (half of sperm get X, half get Y). The type of
sperm that reaches the egg determines the sex.
,●● Do all animals have the same system of sex determination as
humans?
Answer: No. In birds, mom determines sex in a way similar to human
dads. In insects, males are haploid and females are diploid. In turtles, sex
determined by temperature at which eggs are incubated.
●● What are 2 reasons why offspring from sexual reproduction are
genetically different from their parents & each other?
Answer: random fertilization and crossing over
●● random fertilization
Answer: source of genetic variation caused by the unlimited number of
possible sperm & egg combinations (64 trillion genetically different
options)
●● What is crossing over?
Answer: exchange of genetic material between homologous
chromosomes (each individual chromosome becomes a mix of info from
mom and dad)
●● Why is crossing over important?
Answer: -creates gene combinations different from those carried by the
parents' chromosomes
-main reason offspring of sexual reproduction are genetically unique
, ●● What is a nondisjunction?
Answer: -members of a chromosome pair fail to separate in meiosis
-causes abnormal chromosome numbers
-we don't know what causes them
●● What happens if a sperm fertilizes an egg with an abnormal
chromosome number?
Answer: Every cell resulting from this initial error (including the zygote)
will also have the wrong chromosome number
●● Can nondisjunctions lead to abnormal chromosome numbers in
autosomes, sex chromosomes, or both?
Answer: BOTH
●● What happens to a human embryo born with an abnormal # of
autosomes?
Answer: Generally catastrophic and results in miscarriage or survival
with a syndrome
●● What is a syndrome?
Answer: A characteristic set of symptoms that different people have to
varying extents
QUESTIONS AND SOLUTIONS ACCURATE
ANSWERS VERIFIED A+
●● What types of cells does meiosis create?
Answer: sperm and eggs
●● What happens if there are errors during meiosis?
Answer: nondisjunctions (ie. disorders like Down Syndrome)
●● Describe meiosis.
Answer: The process that produces haploid gametes in diploid
organisms
●● How many cell divisions occur during meiosis and how many cells
are produced?
Answer: 2 cell divisions
Meiosis 1- homologous pairs separate
Meiosis 2- sister chromatids separate, resulting in 4 haploid cells, each
containing a copy of each chromosome instead of a homologous pair
●● What is a life cycle?
,Answer: Diploid organisms undergo meiosis to create haploid gametes
Sperm fertilizes an egg to create a zygote which undergoes mitosis to
grow
●● What is a zygote?
Answer: a fertilized egg (diploid)
●● Describe the life cycle of a human.
Answer: Meiosis --> Fertilization --> Mitosis
●● What are the male sex chromosomes?
Answer: XY
●● What are the female sex chromosomes?
Answer: XX
●● Explain why fathers determine the sex of their offspring, instead of
mothers.
Answer: Women have 2 X chromosomes, so an X is always present in
every egg (half of eggs get a copy of one X, the other half get the other
X) whereas men have each (half of sperm get X, half get Y). The type of
sperm that reaches the egg determines the sex.
,●● Do all animals have the same system of sex determination as
humans?
Answer: No. In birds, mom determines sex in a way similar to human
dads. In insects, males are haploid and females are diploid. In turtles, sex
determined by temperature at which eggs are incubated.
●● What are 2 reasons why offspring from sexual reproduction are
genetically different from their parents & each other?
Answer: random fertilization and crossing over
●● random fertilization
Answer: source of genetic variation caused by the unlimited number of
possible sperm & egg combinations (64 trillion genetically different
options)
●● What is crossing over?
Answer: exchange of genetic material between homologous
chromosomes (each individual chromosome becomes a mix of info from
mom and dad)
●● Why is crossing over important?
Answer: -creates gene combinations different from those carried by the
parents' chromosomes
-main reason offspring of sexual reproduction are genetically unique
, ●● What is a nondisjunction?
Answer: -members of a chromosome pair fail to separate in meiosis
-causes abnormal chromosome numbers
-we don't know what causes them
●● What happens if a sperm fertilizes an egg with an abnormal
chromosome number?
Answer: Every cell resulting from this initial error (including the zygote)
will also have the wrong chromosome number
●● Can nondisjunctions lead to abnormal chromosome numbers in
autosomes, sex chromosomes, or both?
Answer: BOTH
●● What happens to a human embryo born with an abnormal # of
autosomes?
Answer: Generally catastrophic and results in miscarriage or survival
with a syndrome
●● What is a syndrome?
Answer: A characteristic set of symptoms that different people have to
varying extents
