{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Ch13 Meiosis - Meiosis chapter 13 PowerPoint Lectures for...

Info icon This preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style 11/10/10 Meiosis chapter 13 PowerPoint Lectures for Biology 8th edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions by Joan Sharp
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
11/10/10 Concept 13.1: Offspring acquire genes from parents by inheriting Living organisms are distinguished by their ability to reproduce their own kind Genetics is the scientific study of heredity and variation Heredity is the transmission of traits from one generation to the next l DNA (genes) Variation is demonstrated by the differences in appearance that offspring
Image of page 2
11/10/10 Meiosis Meiosis allows heredity (passing of DNA) to occur without abnormal duplication of the DNA Meiosis also provides a mechanism to introduce variation Genes are the units of heredity, and are made up of segments of DNA l Each gene has a specific location called a locus on a certain chromosome Slight changes in nucleotide sequences in genes make them different in one
Image of page 3

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

View Full Document Right Arrow Icon
11/10/10 Meiosis and chromosomes Genes for same trait, but slightly different.
Image of page 4
11/10/10 Homologous Chromosomes Homologous Chromosomes l These are chromosomes that contain the same genes (information about the same trait) and structurally look similar. Human somatic cells (any cell other than a gamete) have 23 pairs of chromosomes l A karyotype is an ordered display of the pairs of chromosomes from a cell
Image of page 5

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

View Full Document Right Arrow Icon
11/10/10 Homologous Chromosomes
Image of page 6
11/10/10 Homologous Chromosomes Homologous Chromosomes l For each pair of homologous chromosomes, one chromosome came from Mom, and one came from Dad. l An exception to the rule of homologous chromosomes is found in the sex chromosomes , the X and the Y. Human females have a homologous pair of X chromosomes (XX). Human males have an X and a Y chromosome (XY). l The 22 pairs of chromosomes that do not
Image of page 7

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

View Full Document Right Arrow Icon
11/10/10 Homologous Chromosomes - karyotype Sex Chromosomes Autoso mes
Image of page 8
11/10/10 Concept 13.2: Fertilization and meiosis alternate in Meiosis separates Homologous chromosomes and fertilization reunites them. A life cycle is the generation-to- generation sequence of stages in the reproductive history of an organism
Image of page 9

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

View Full Document Right Arrow Icon
11/10/10 Diploid cells have homologous chromosomes q A diploid cell (2 n ) has two sets of chromosomes q This is the case for somatic cells q For humans, the diploid number is 46 (2 n = 46) q Remember: q In a cell in which DNA synthesis has occurred, each chromosome is replicated q Each replicated chromosome consists of two identical sister chromatids
Image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}