{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

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

Info icon This 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
Image of page 1

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

View Full Document Right Arrow Icon
Twin studies Plomin & Defries (1985): Temperament o Monozygotic vs. dizygotic twins o Emotionality, sociability MZ: concordance (correlation) rate = .55 DZ: Concordance rate = 0 o Outcome: Temperament has genetic basis.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern