Heredity and Genetics (C652)(WGU) exam
with complete solutions
gene - ANSWER- a string of nucleotides within a DNA molecule that is the basic
structural and functional unit of genetics
allele - ANSWER- this is the term for one of a number of different forms of a gene
phenotype - ANSWER- physical characteristics of an organism
genotype - ANSWER- genetic makeup of an organism
heterozygous - ANSWER- this term describes an organism that has two different
alleles for a trait
homozygous - ANSWER- this term describes an organism that has two identical
alleles for a trait
dominant - ANSWER- describes a trait that covers over, or dominates, another
form of that trait
recessive - ANSWER- an allele that is masked when a dominant allele is present
meiosis - ANSWER- cell division that produces reproductive cells in sexually
reproducing organisms; one diploid cell containing forty six chromosomes
undergoes one round of chromosome replication and two rounds of division to
produce four haploid cells each of which contains one copy of each chromosome
Interphase - ANSWER- this is the phase during which the chromosomes replicate
Prophase I - ANSWER- during this phase chromosomes condense and become
visible under a microscope, the nuclear envelope disappears, and the spindle
becomes organized
, Metaphase I - ANSWER- during this phase paired homologous chromosomes line
up at the equator of the cell with each chromosome attached to spindle fibers
from opposite poles of the cell
Anaphase I - ANSWER- during this phase the paired chromatids are separated
from each other and move towards opposite sides of the cell
Telophase I - ANSWER- during this phase the cytoplasm begins to divide
resulting in two haploid cells
Prophase II - ANSWER- during this phase the unpaired chromosomes consist of
two sister chromatids joined by a centromere
Metaphase II - ANSWER- during this phase the twenty three unpaired
chromosomes are at the equator of the cell with spindle fibers from opposite
poles of the cell attached to their centromeres
Anaphase II - ANSWER- during this phase spindle fibers pull the chromatids apart
in both cells
Telophase II - ANSWER- during this phase the chromosomes uncoil and the
nuclear envelope reforms and the cytoplasm begins to split resulting in four
haploid cells
crossing over - ANSWER- this is the process in which homologous chromosomes
exchange portions of their chromatids during the first prophase and metaphase
in meiosis and this allows for genetic codes to be swapped between homologous
pairs of chromosomes
Principle of Segregation (Mendel's First Law) - ANSWER- this principle states that
members of a gene pair must separate or segregate from each other during
gamete formation and each gamete receives only one of the two genes that
control a particular trait
Principle of Independent Assortment - ANSWER- this principle states that genes
for different traits can segregate independently during the formation of gametes
incomplete dominance - ANSWER- this describes a situation in which one allele
is not completely dominant over another allele such as a red flower crossing with
a white flower and producing a pink flower
with complete solutions
gene - ANSWER- a string of nucleotides within a DNA molecule that is the basic
structural and functional unit of genetics
allele - ANSWER- this is the term for one of a number of different forms of a gene
phenotype - ANSWER- physical characteristics of an organism
genotype - ANSWER- genetic makeup of an organism
heterozygous - ANSWER- this term describes an organism that has two different
alleles for a trait
homozygous - ANSWER- this term describes an organism that has two identical
alleles for a trait
dominant - ANSWER- describes a trait that covers over, or dominates, another
form of that trait
recessive - ANSWER- an allele that is masked when a dominant allele is present
meiosis - ANSWER- cell division that produces reproductive cells in sexually
reproducing organisms; one diploid cell containing forty six chromosomes
undergoes one round of chromosome replication and two rounds of division to
produce four haploid cells each of which contains one copy of each chromosome
Interphase - ANSWER- this is the phase during which the chromosomes replicate
Prophase I - ANSWER- during this phase chromosomes condense and become
visible under a microscope, the nuclear envelope disappears, and the spindle
becomes organized
, Metaphase I - ANSWER- during this phase paired homologous chromosomes line
up at the equator of the cell with each chromosome attached to spindle fibers
from opposite poles of the cell
Anaphase I - ANSWER- during this phase the paired chromatids are separated
from each other and move towards opposite sides of the cell
Telophase I - ANSWER- during this phase the cytoplasm begins to divide
resulting in two haploid cells
Prophase II - ANSWER- during this phase the unpaired chromosomes consist of
two sister chromatids joined by a centromere
Metaphase II - ANSWER- during this phase the twenty three unpaired
chromosomes are at the equator of the cell with spindle fibers from opposite
poles of the cell attached to their centromeres
Anaphase II - ANSWER- during this phase spindle fibers pull the chromatids apart
in both cells
Telophase II - ANSWER- during this phase the chromosomes uncoil and the
nuclear envelope reforms and the cytoplasm begins to split resulting in four
haploid cells
crossing over - ANSWER- this is the process in which homologous chromosomes
exchange portions of their chromatids during the first prophase and metaphase
in meiosis and this allows for genetic codes to be swapped between homologous
pairs of chromosomes
Principle of Segregation (Mendel's First Law) - ANSWER- this principle states that
members of a gene pair must separate or segregate from each other during
gamete formation and each gamete receives only one of the two genes that
control a particular trait
Principle of Independent Assortment - ANSWER- this principle states that genes
for different traits can segregate independently during the formation of gametes
incomplete dominance - ANSWER- this describes a situation in which one allele
is not completely dominant over another allele such as a red flower crossing with
a white flower and producing a pink flower
