BIO 235 Unit 1 Study Guide | Questions with 100%
Verified Answers | Latest Update 2026/2027
Question: Homogametic
Answer: XX
Question: Hetergametic
Answer: XY
Question: SRY - Sex Determining Region
Answer: Encodes Testis Determining Factor
Promotes male-typical reproductive development
Question: PAR - Pseudoautosomal Region
Answer: Allows the X and Y chromosomes to pair up and swap DNA
Region of shared X-Y homology (they are not homologous)
Question: MSY - Male specific region of Y
Answer: Designed to avoid crossing over
- too much variation can lead to reproductive issues
Question: Euchromatin
Answer: heavily expressed
Question: Heterochromatin
Answer: so compact, it's hardly expressed
Question: mosaicism
Answer: Female mammals are therefore mosaics of cells—some cells have the maternal X
inactive
and others the paternal X inactive.
Females that are heterozygous at an x-link loci express one allele in 50% of the cells
and
the other allele in the other 50%
Question: Barr Body
Answer: Inactive X chromosome
condensed heterochromatin is visible as a barr body
Question: Aneuploidy
Answer: abnormal variation in the sex chromosome copy
, Question: Bird sex chromosmes:
Answer: Females: ZW
Male: ZZ
Question: Some reptile genders are determined by
Answer: Temperature
Temperature-dependent sex determination (TSD)
- Expression of aromatase genes is affected by temperature
- Aromatase enzymes turn androgens into estrogens
Question: Pangenesis
Answer: Shedding cells into ovaries to pass on traits
Question: germ-plasm theory
Answer: traits passed on only through sex cells
Question: Genetic variation is caused by
Answer: crossing over
Random assortment of maternal and paternal chromosomes
Question: Gametogenesis (oogenesis)
Answer: Discontinuous, stops in later life
- cytokenisis is uneven, which creates one larger cell and one smaller cell
Question: Spermatogenesis
Answer: Continuous through entire life
Question: Meiosis is responsible for
Answer: genetic diversity
Question: Turner's Syndrom
Answer: XO, female traits
Question: Kleinfelters Syndrome
Answer: XXY, XXYY, XXXY, male traits
Question: Poly-X females
Answer: XXX, XXXX, XXXXX, female traits
Question: Y0
Answer: having no X chromosome is lethal
Verified Answers | Latest Update 2026/2027
Question: Homogametic
Answer: XX
Question: Hetergametic
Answer: XY
Question: SRY - Sex Determining Region
Answer: Encodes Testis Determining Factor
Promotes male-typical reproductive development
Question: PAR - Pseudoautosomal Region
Answer: Allows the X and Y chromosomes to pair up and swap DNA
Region of shared X-Y homology (they are not homologous)
Question: MSY - Male specific region of Y
Answer: Designed to avoid crossing over
- too much variation can lead to reproductive issues
Question: Euchromatin
Answer: heavily expressed
Question: Heterochromatin
Answer: so compact, it's hardly expressed
Question: mosaicism
Answer: Female mammals are therefore mosaics of cells—some cells have the maternal X
inactive
and others the paternal X inactive.
Females that are heterozygous at an x-link loci express one allele in 50% of the cells
and
the other allele in the other 50%
Question: Barr Body
Answer: Inactive X chromosome
condensed heterochromatin is visible as a barr body
Question: Aneuploidy
Answer: abnormal variation in the sex chromosome copy
, Question: Bird sex chromosmes:
Answer: Females: ZW
Male: ZZ
Question: Some reptile genders are determined by
Answer: Temperature
Temperature-dependent sex determination (TSD)
- Expression of aromatase genes is affected by temperature
- Aromatase enzymes turn androgens into estrogens
Question: Pangenesis
Answer: Shedding cells into ovaries to pass on traits
Question: germ-plasm theory
Answer: traits passed on only through sex cells
Question: Genetic variation is caused by
Answer: crossing over
Random assortment of maternal and paternal chromosomes
Question: Gametogenesis (oogenesis)
Answer: Discontinuous, stops in later life
- cytokenisis is uneven, which creates one larger cell and one smaller cell
Question: Spermatogenesis
Answer: Continuous through entire life
Question: Meiosis is responsible for
Answer: genetic diversity
Question: Turner's Syndrom
Answer: XO, female traits
Question: Kleinfelters Syndrome
Answer: XXY, XXYY, XXXY, male traits
Question: Poly-X females
Answer: XXX, XXXX, XXXXX, female traits
Question: Y0
Answer: having no X chromosome is lethal
