29 - 560 1/29 29/01/2009 12:57:00 Meiosis Typical cells: 46...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
560 1/29 29/01/2009 12:57:00 Meiosis Typical cells: 46 chromosomes each (23 pairs) Gametes: 23 chromosomes each o Create via meiosis o Sperm and egg Each gamete comes with ½ of the parent cell’s set Germ cells—combine to create zygote (fertilized egg) o Zygote: 1 or more cells 46 chromosomes (23 pairs) each contains ~ 20,000 genes o Growth of zygote: Mitosis New cells via duplication and division Genetic diversity Meiosis: zygote differs from each parent Crossing-over: genetic material exchanged between paired chromosomes during meiosis Multiple births Identical twins: cell mass separates during early mitosis Monozygotic: one zygote 1 in 250 live births Fraternal twins 2 sperm, 2 eggs at the same time dizygotic: 2 zygotes 1 in 30 live births 74% increase 1980-2000 o fertility treatments
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Twin studies o Monozygotic vs. dizygotic twins o Emotionality, sociability MZ: concordance (correlation) rate = .55
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

29 - 560 1/29 29/01/2009 12:57:00 Meiosis Typical cells: 46...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online