RIO BIO 156 MIDTERM ACTUAL
CERTIFICATION SCRIPT 2026 EXTENSIVE
QUESTIONS WITH PRECISELY ANALYZED
CORRECT ANSWERS GRADED A+
⩥ In an individual with a dominant phenotype is crossed with an
individual with a recessive phenotype, 4 of their 9 offspring show the
recessive phenotype. What is the genotype of the first parent? Answer:
Bb
⩥ Solve this monohybrid genetics problem: Black hair is governed by
the dominant gene (B) and blond hair is determined by the recessive
gene (b). In this monohybrid cross, if both parents are heterozygous,
what percentage of the offspring would be expected to have blond hair?
Answer: 25%
⩥ A Punnett square can be used to determine___________. Answer: the
genotype of an offspring
⩥ Different alleles of the same gene are found Answer: at the same place
on homologous chromosomes
,⩥ If a parental cell has 14 chromosomes prior to mitosis, how many
chromosomes will each daughter cell have? Answer: 14 because the
chromatids separate
⩥ a duplicated chromosome has _____ chromatid(s) Answer: 2
⩥ Mendel was fortunate to work out the laws of segregation and
independent assortment because he used an organism that reproduced
quickly and in which the traits were discrete (easy to observe). Mendel's
organism of choice was the Answer: pea plant
⩥ What is the importance of crossing-over? Answer: It increases the
likelihood that daughter cells contain different genetic material.
⩥ Assuming that the probability of having a female child is 50% and the
probability of having a male child is also 50%, what is the probability
that a couple's firstborn child is female and second-born child is male?
Answer: 25%
⩥ If a parental cell has 12 chromosomes, then each of the daughter cells
following meiosis will have _____. Answer: 6 chromosomes.
⩥ Which of the following genotypes would be homozygous dominant
for both alleles? Answer: DDEE
, ⩥ Which sequence of stages in mitosis is correct? Answer: prophase,
prometaphase, metaphase, anaphase, telophase
⩥ During which stage of meiosis does crossing-over occur? Answer:
prophase I
⩥ Which occurs in anaphase? Answer: Chromosomes move to opposite
poles.
⩥ If both parents in a dihybrid cross are heterozygous for both traits, the
expected phenotypic ratio in the offspring would be Answer: 9:3:3:1
⩥ A pair of chromosomes that are similar in length, shape, and the traits
they govern are called ____. Answer: homologous chromosomes
⩥ If a pea plant shows a recessive phenotype, _____. Answer: it can
only be tt
⩥ The offspring of a monohybrid testcross would show the genotype(s)
_____. Answer: Aa and aa
⩥ In which kind of cross would you expect to find a ratio of 3:1 among
the F2 offspring? Answer: monohybrid cross
CERTIFICATION SCRIPT 2026 EXTENSIVE
QUESTIONS WITH PRECISELY ANALYZED
CORRECT ANSWERS GRADED A+
⩥ In an individual with a dominant phenotype is crossed with an
individual with a recessive phenotype, 4 of their 9 offspring show the
recessive phenotype. What is the genotype of the first parent? Answer:
Bb
⩥ Solve this monohybrid genetics problem: Black hair is governed by
the dominant gene (B) and blond hair is determined by the recessive
gene (b). In this monohybrid cross, if both parents are heterozygous,
what percentage of the offspring would be expected to have blond hair?
Answer: 25%
⩥ A Punnett square can be used to determine___________. Answer: the
genotype of an offspring
⩥ Different alleles of the same gene are found Answer: at the same place
on homologous chromosomes
,⩥ If a parental cell has 14 chromosomes prior to mitosis, how many
chromosomes will each daughter cell have? Answer: 14 because the
chromatids separate
⩥ a duplicated chromosome has _____ chromatid(s) Answer: 2
⩥ Mendel was fortunate to work out the laws of segregation and
independent assortment because he used an organism that reproduced
quickly and in which the traits were discrete (easy to observe). Mendel's
organism of choice was the Answer: pea plant
⩥ What is the importance of crossing-over? Answer: It increases the
likelihood that daughter cells contain different genetic material.
⩥ Assuming that the probability of having a female child is 50% and the
probability of having a male child is also 50%, what is the probability
that a couple's firstborn child is female and second-born child is male?
Answer: 25%
⩥ If a parental cell has 12 chromosomes, then each of the daughter cells
following meiosis will have _____. Answer: 6 chromosomes.
⩥ Which of the following genotypes would be homozygous dominant
for both alleles? Answer: DDEE
, ⩥ Which sequence of stages in mitosis is correct? Answer: prophase,
prometaphase, metaphase, anaphase, telophase
⩥ During which stage of meiosis does crossing-over occur? Answer:
prophase I
⩥ Which occurs in anaphase? Answer: Chromosomes move to opposite
poles.
⩥ If both parents in a dihybrid cross are heterozygous for both traits, the
expected phenotypic ratio in the offspring would be Answer: 9:3:3:1
⩥ A pair of chromosomes that are similar in length, shape, and the traits
they govern are called ____. Answer: homologous chromosomes
⩥ If a pea plant shows a recessive phenotype, _____. Answer: it can
only be tt
⩥ The offspring of a monohybrid testcross would show the genotype(s)
_____. Answer: Aa and aa
⩥ In which kind of cross would you expect to find a ratio of 3:1 among
the F2 offspring? Answer: monohybrid cross
