and sexual life cycles

Gamete

Sexual Reproduction (animals)Gamete

Zygote

Fertilization (n + n 2n) Mitosis produces

subsequent somatic cells Meiosis

(2n n + n + n + n)Gametes

Meiosis I – homologous pairs separate

Synapsis Homologous

chromosomes form tetrads

Chiasmata may result

Paternal and maternal chromatids recombine (cross over)

Meiosis I – homologous pairs separate

Meiosis II –pairs separate

Crossing Over

Independent Assortment

Crossing Over

Independent Assortment

Summary Comparison

Animal Sexual Life Cycle

MEIOSIS FERTILIZATION

n

n

n

2n2n

2n2n2n2n

2n 2n2n

2n2n2n

2n2n2n

2n2n2n

2n2n

2n2n

2n

MEIOSIS FERTILIZATION

nn

n

n

2n

n n n n nn

nnnnnn

nnnn n n nnnnn n

n n

Fungal/ProtistSexual Life Cycle

Plant Sexual Life Cycle

MEIOSIS FERTILIZATION

2n2n

2n2n2n

2n 2n2n

2n2n2n

2n2n2n

2n2n2n

2n2n

2n2n

2n

n n n n nn

nnnnnn

nnnn n n nnnnn n

n n

n n nn

2n