Meiosis Producing Sex Cells.

Slides:

Advertisements

Similar presentations

Meiosis is a special form of cell division.

Advertisements

Sexual Reproduction: Meiosis.

Meiosis is a Special Type of Cell Division that Occurs in Sexually Reproducing Organisms Meiosis reduces the chromosome number by half, enabling sexual.

Sexual Reproduction: Meiosis.

Meiosis Notes Cell division to form the gametes, sperm (male gamete) and egg (female gamete). Normal cells are diploid (2n): 2 copies of every gene. Gametes.

Meiosis Chapter 10, Section 2.

Meiosis and Karyotypes

CH 10.2 Meiosis.

Producing Gametes (eggs & sperm)

Think: We have discussed how somatic cells (body cells other than the gametes) are formed…what process forms the sex cells (the gametes- sperm/egg)? Take.

Section 10.2 Summary – pages

MEIOSIS Variety is the Spice of Life!. SEXUAL REPRODUCTION  The production of offspring from the fusion of two sex cells  Usually from two different.

1. CHROMOSOMES 2 CHROMOSOME NUMBER  All cells in the human body (SOMATIC CELLS) have 46 or 23 pairs of chromosomes  Called the DIPLOID or 2n number.

1copyright cmassengale. Chromosomes 2 Chromosome Number All cells in the human body (SOMATIC CELLS) have 46 or 23 pairs of chromosomes Called the DIPLOID.

1. Chromosomes 2 Chromosome Number All cells in the human body (SOMATIC CELLS) have 46 or 23 pairs of chromosomes Called the DIPLOID or 2n number GAMETES.

Meiosis. Reproduction Mitosis produces somatic cells (body cells) Somatic cells have 46 chromosomes (23 pairs) What if somatic cells were involved in.

Meiosis Division of Sex Cells. Meiosis  A process of reduction division in which the number of chromosomes per cell is cut in half through the separation.

Inheritance of Traits Sexual reproduction In organisms that reproduce sexually, traits are inherited through gametes. Gametes (sperm and eggs) are produced.

MEIOSIS AND CROSSING OVER Chromosomes are matched in homologous pairs Homologous chromosomes: the 2 members of a pair of chromosomes—contain genes for.

DO NOW: What is the difference between asexual and sexual reproduction?

Meiosis Chapter 10.

Meiosis. The Diploid Cell Cell with 2 sets of chromosomes Contains chromosomes for each homologous pair Somatic Cells = Body Cells: Diploid All human.

 Cross TT X Tt  Give the genotypic and phenotypic ratios.

Meiosis Division of sex cells. Meiosis Cell Division to make 4 new, genetically different sex cells.

12/8/13 Objective: How does meiosis contribute to genetic variation? Do Now: -Take out your notes, online lab, and cancer activity from Friday.

Meiosis does two things - 1) Meiosis takes a cell with two copies of every chromosome (diploid) and makes cells with a single copy of every chromosome.

MEIOSIS Ch. 8 CELLS FOR SEXUAL REPRODUCTION. Meiosis for Sexual Reproduction Sexual Reproduction - two parents a. Offspring are genetic mix of both parents.

MEIOSIS: Sexual Reproduction Ch. 9.7 – EGG SPERM.

Meiosis and Nondisjunction. Meiosis Definition: Cell division that divides the number of chromosomes per cell in half to produce sperm and eggs.

Meiosis Chapter 10, Section 2.

Meiosis Chapter 8.

Reduction-Division Genetic Recombination

Meiosis Division of Sex Cells.

Meiosis SC.912.L

Cell Division: Meiosis

KEY CONCEPT Meiosis creates sex cells that are haploid.

Meiosis; Chapter 6.2 I. Purpose of meiosis is to create a gamete that is haploid (half the normal number of chromosomes), from a diploid cell (complete.

Meiosis Meiosis is a form of nuclear division that divides a diploid cell into haploid cells. This process is essential for sexual reproduction. Only takes.

Sources of Genetic Variation

SEXUAL REPRODUCTION.

Chapter 11.4 Meiosis.

Cells For Sexual Reproduction

Meiosis Chapter 8.

Unit 5 Cell Division Review

Chromosomes & Karyotypes

The same genes, but different forms (alleles) of those genes

Cell Division Meiosis.

Meiosis Division of Sex Cells.

Meiosis I results in 2 haploid daughter cells

Sexual Reproduction and Meiosis

Meiosis Division of Sex Cells.

Week 8 Vocab Definitions

The formation of gametes (sex cells)

Welcome to Jeopardy!.

MEIOSIS … making gametes….

Meiosis and Sexual Reproduction

CHROMOSOMES As a eukaryotic cell prepares to divide the DNA

Meiosis; Chapter 6.2 I. Purpose of meiosis is to create a gamete that is haploid (half the normal number of chromosomes), from a diploid cell (complete.

Meiosis Meiosis covered in Chapter 8 in Modern Biology Chapter 11 (HB)

Fertilization The process of haploid gametes joining together to form a diploid cell with 2n chromosomes. n chromosomes come from the male parent and n.

Biology Pop-quiz Review

Meiosis Division of Sex Cells.

Meiosis Division of Sex Cells.

Presentation transcript:

Meiosis Producing Sex Cells

I. How Many Possible Chromosome combos? In a human gamete: 23 pairs of chromosomes - one from each pair in a sperm or egg.

If there were only one pair, how many ways would there be to pass on one chromosome? From two pairs? Three pairs? Hmmm, I see a pattern… And where there’s a pattern, there’s a formula.

The equation F(x)= 2x X = # of pairs. Possible combinations is… 2 to choose from in each pair. Possible combinations is… 8,388,608 Finally: For 2 of those cells to combine? (8,388,608)2

Meiosis Produces sex cells - gametes Somatic (body) cells have pairs of homologous chromosomes. Same genes at same locus (location). These are Diploid – 2n N is number of each chromosome type. Humans: 2n = 46 Gametes: n = 23. Haploid cells That’s a lot of vocab Bro!

Karyotype Photograph that shows all pairs. Can diagnose extra/missing chromosomes/fragments. Down Syndrome, Klinefelter, etc

Quick Quiz Llama sperm/egg cells have 38 chromosomes. What is the N #? 2N? Are sperm haploid or diploid?

Meiosis I cell’s DNA is copied (4n) Tetrad – 4 chromatids line up During Prophase I

Crossing Over A piece of one chromosome is cut out, switching with the same piece on its homolog. Recombinant chromosomes. Creates new genetic combinations. Chances of identical gametes is basically zero.

Meiosis I Like Mitosis Chrom. separated into 2 cells. Sister chrom. still together.

Meiosis II Sister chr. are pulled apart. Cell divides again. 4 total cells produced. Each has n number.

Mistakes During Meiosis Nondisjunction Failure of a pair of chromosomes to separate correctly. Spindle fails to attach properly at centromere. Result: both chromatids go one way. Nondisjunction. Gamete with too many/few chromosomes. Usually lethal. Down Syndrome - 3 copies (Trisomy) of chr. 21.

Sex- Chromosomes XXY - Kleinfelter syndrome XO - Turner Syndrome Male sex organs, testes abnormally small, sterile. Breast enlargement, normal intelligence. How Frequent? 1 per 1000 male births. XO - Turner Syndrome Lacking an X. Develops as a woman Short stature Sterile because sex organs don’t fully mature. Frequency: 1 per 2500 female births.