Sex Chromosomes: Animal Species Match

Correct Answer: 1-b, 2-d, 3-a, 4-c

From the notes and Table 1 (Chromosome numbers):

• 1. Poultry female (b) = 76 + ZW: Female birds are heterogametic (ZW). Total diploid = 78.
• 2. Human Male (d) = 44 + XY: Human males are heterogametic (XY). Total diploid = 46.
• 3. Poultry Male (a) = 76 + ZZ: Male birds are homogametic (ZZ). Total diploid = 78.
• 4. Human Female (c) = 44 + XX: Human females are homogametic (XX). Total diploid = 46.

Key Contrast

• In mammals → Male is heterogametic (XY); Female is homogametic (XX)
• In birds → Female is heterogametic (ZW); Male is homogametic (ZZ)

Chromosomal Abnormalities in Humans (from notes)

• Klinefelter's syndrome: 47 (44 + XXY)
• Turner syndrome: 45 (44 + XO) — Number of Barr bodies = 0
• Super male / Jacob's syndrome: 47 (44 + XYY)
• Super female: 47 (44 + XXX)