Bio 1406: Exam #4 (Ch. 11-14)
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Purpose of meiosis - ANS ✔✔To make gamete cells (haploid) for sexual reproduction.
products of meiosis - ANS ✔✔4 haploid (daughter cells) gametes genetically unique to each
other and parent cells. The daughter cells have 1/2 # of chromosomes
crossing over - ANS ✔✔Process in which homologous chromosomes exchange portions of their
chromatids during meiosis.
site: chiasmata
Recombination nodules: thought to contain enzymatic machinery necessary to break & rejoin
chromatids of homologous chromosomes
phenotype - ANS ✔✔physical characteristics of an organism
dominant - ANS ✔✔An allele that is always expressed.
Mendel referred form of trait expressed in F1 plants
recessive - ANS ✔✔An allele that is masked when a dominant allele is present.
Alternative form that was not expressed in F1 plants
testcross - ANS ✔✔an individual of unknown genotype is crossed with a homozygous recessive
individual
pleiotropy - ANS ✔✔The ability of a single gene that affects more than 1 trait.
, Pleiotropic- Allele that has more than 1 effect on phenotype
sex-linked - ANS ✔✔An inheritance pattern in which traits are controlled by genes located on
the X chromosome.
autosomes - ANS ✔✔Any chromosome that is not a sex chromosome (22 pairs)
Barr bodies - ANS ✔✔inactivated X chromosomes found only in females early in embryonic
development after sex is determined.
non-disjunction - ANS ✔✔failure of homologues of sister chromatids to separate properly
during meiosis. Failure of chromosomes to move to opposite poles during either meiotic
division.
alleles - ANS ✔✔alternative forms of a gene
polygenic traits - ANS ✔✔traits controlled by two or more genes
aneuploid - ANS ✔✔Having too many or too few copies of a particular chromosome
aneuploidy- gain or loss of chromosome
outcomes of monohybrid cross - ANS ✔✔Phenotype- 3:1 (dom:rec)
Genotype- 1:2:1 (Homozygous dom, heterozygous, Homozygous rec)
questions n answers rated A+
Purpose of meiosis - ANS ✔✔To make gamete cells (haploid) for sexual reproduction.
products of meiosis - ANS ✔✔4 haploid (daughter cells) gametes genetically unique to each
other and parent cells. The daughter cells have 1/2 # of chromosomes
crossing over - ANS ✔✔Process in which homologous chromosomes exchange portions of their
chromatids during meiosis.
site: chiasmata
Recombination nodules: thought to contain enzymatic machinery necessary to break & rejoin
chromatids of homologous chromosomes
phenotype - ANS ✔✔physical characteristics of an organism
dominant - ANS ✔✔An allele that is always expressed.
Mendel referred form of trait expressed in F1 plants
recessive - ANS ✔✔An allele that is masked when a dominant allele is present.
Alternative form that was not expressed in F1 plants
testcross - ANS ✔✔an individual of unknown genotype is crossed with a homozygous recessive
individual
pleiotropy - ANS ✔✔The ability of a single gene that affects more than 1 trait.
, Pleiotropic- Allele that has more than 1 effect on phenotype
sex-linked - ANS ✔✔An inheritance pattern in which traits are controlled by genes located on
the X chromosome.
autosomes - ANS ✔✔Any chromosome that is not a sex chromosome (22 pairs)
Barr bodies - ANS ✔✔inactivated X chromosomes found only in females early in embryonic
development after sex is determined.
non-disjunction - ANS ✔✔failure of homologues of sister chromatids to separate properly
during meiosis. Failure of chromosomes to move to opposite poles during either meiotic
division.
alleles - ANS ✔✔alternative forms of a gene
polygenic traits - ANS ✔✔traits controlled by two or more genes
aneuploid - ANS ✔✔Having too many or too few copies of a particular chromosome
aneuploidy- gain or loss of chromosome
outcomes of monohybrid cross - ANS ✔✔Phenotype- 3:1 (dom:rec)
Genotype- 1:2:1 (Homozygous dom, heterozygous, Homozygous rec)
