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10 Cards in this Set
- Front
- Back
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Chromosomal sex determination
1891 |
Cytologists studying chromosomes found the unpaired “X
chromosome” in males. |
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Chromosomal sex determination
1903 |
Walter Sutton proposed the Chromosomal Theory of
Inheritance stating that genes are on chromosomes. |
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Chromosomal sex determination
1905 - 1910 |
Geneticists decipher the XX-XY system of sex
determination and discover some genes on sex chromosomes. |
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Heterogametic sex
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Produce 2 different gametes
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Homogametic sex
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Produce 1 gamete
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Chromosomal Sex Determination:
Patterns of Inheritance (3) |
- sex determination depends on the
sperm - Y chromosomes are inherited only from father to son. - In males, X chromosomes are inherited from mothers and passed on to daughters only. |
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Chromosomes other than X and Y are called...
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AUTOSOMES
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In Non-chromosomal sex determination (2 points)
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1. One or more loci determine sex, but there are no
morphologically different sex chromosomes. 2. Environmental sex determination. |
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In mating experiments, X-linked inheritance can be identified by: (3 points)
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1) Reciprocal crosses lead to different phenotypic ratios in the sexes.
2) Suspected heterozygous female transmits alleles to both daughters and sons in a 1:1 ratio. 3) In males, the X-linked phenotype tells you the genotype. |
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Y-linked inheritance
(1 point) |
Y chromosome is inherited ONLY from father to son.
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