SBI3U- Exam Review Questions with
complete solution 2025
prophase - correct answer Chromosomes become visible, nuclear envelop
dissolves, spindle forms
interphase - correct answer Cell grows, performs its normal functions, and
prepares for division; consists of G1, S, and G2 phases
anaphase - correct answer the third phase of mitosis, during which the
chromosome pairs separate and move toward opposite poles
allele - correct answer Different forms of a gene
genotype - correct answer An organism's genetic makeup, or allele
combinations.
phenotype - correct answer An organism's physical appearance, or visible
traits.
pedigree - correct answer A chart or "family tree" that tracks which members
of a family have a particular trait
karyotype - correct answer the number and visual appearance of the
chromosomes in the cell nuclei of an organism or species.
nondisjunction - correct answer Error in meiosis in which homologous
chromosomes fail to separate.
, Down Syndrome - correct answer (Trisomy 21) Occurs when an individual
has 3 chromosomes on the 21st pair instead of 2; caused by
NONDISJUNCTION
incomplete dominance - correct answer A pattern of inheritance in which two
alleles, inherited from the parents, are neither dominant nor recessive. The
resulting offspring have a phenotype that is a blending of the parental traits.
complete dominance - correct answer a relationship in which one allele is
completely dominant over another
codominance - correct answer A condition in which both alleles for a gene are
fully expressed
centromere - correct answer Region of a chromosome where the two sister
chromatids attach
gamete - correct answer specialized cell involved in sexual reproduction
tetrad - correct answer structure containing 4 chromatids that forms during
meiosis
nucleotides - correct answer Basic units of DNA molecule, composed of a
sugar, a phosphate, and one of 4 DNA bases
RNA - correct answer A single-stranded nucleic acid that passes along
genetic messages
complete solution 2025
prophase - correct answer Chromosomes become visible, nuclear envelop
dissolves, spindle forms
interphase - correct answer Cell grows, performs its normal functions, and
prepares for division; consists of G1, S, and G2 phases
anaphase - correct answer the third phase of mitosis, during which the
chromosome pairs separate and move toward opposite poles
allele - correct answer Different forms of a gene
genotype - correct answer An organism's genetic makeup, or allele
combinations.
phenotype - correct answer An organism's physical appearance, or visible
traits.
pedigree - correct answer A chart or "family tree" that tracks which members
of a family have a particular trait
karyotype - correct answer the number and visual appearance of the
chromosomes in the cell nuclei of an organism or species.
nondisjunction - correct answer Error in meiosis in which homologous
chromosomes fail to separate.
, Down Syndrome - correct answer (Trisomy 21) Occurs when an individual
has 3 chromosomes on the 21st pair instead of 2; caused by
NONDISJUNCTION
incomplete dominance - correct answer A pattern of inheritance in which two
alleles, inherited from the parents, are neither dominant nor recessive. The
resulting offspring have a phenotype that is a blending of the parental traits.
complete dominance - correct answer a relationship in which one allele is
completely dominant over another
codominance - correct answer A condition in which both alleles for a gene are
fully expressed
centromere - correct answer Region of a chromosome where the two sister
chromatids attach
gamete - correct answer specialized cell involved in sexual reproduction
tetrad - correct answer structure containing 4 chromatids that forms during
meiosis
nucleotides - correct answer Basic units of DNA molecule, composed of a
sugar, a phosphate, and one of 4 DNA bases
RNA - correct answer A single-stranded nucleic acid that passes along
genetic messages
