meiosis
Meiosis produces germ cells, or gametes with half (haploid) the number of chromosomes of a diploid cell.
First cell division: single diploid parent cell successively passes through:
1. prophase 1
2. metaphase 1
3. anaphase 1
4. telophase 1 & prophase 2
Second cell division
5. metaphase 2
6. anaphase 2
7. telophase 2,
producing 4 haploid daughter cells.
(image mitosis vs meiosis)
Recombination provides a mechanism for genetic variability and is a mechanism of biological evolution. Recombination between homologous chromosomes in meiosis I involves the formation and repair of double strand breaks (DSBs), and meiosis I employs the same enzymes as does DSB repair. Many biologists consider the main function of sexual reproduction is to provide this mechanism for maintaining the integrity of the genome.
• A • adhesion • C • cell membranes • cellular adhesion molecules • cellular signal transduction • centrioles • chemotaxis • chloroplast • cilia & flagella • communication • concentration gradients • cytokine receptors • cytoplasm • cytoskeleton • E • energy transducers • endoplasmic reticulum • endosomes • exosome • F • flagella & cilia • G • Golgi apparatus • GPCRs • H • hormones • I • ion channels • L • lysosome • M • meiosis • microtubules • mitosis • mitochondrion • N • Nitric Oxide • neurotransmission • neuronal interconnections • nuclear membrane • nuclear pore • P • pinocytosis • proteasome • pumps • R • receptor proteins • receptor-mediated endocytosis • S • second messengers • signaling gradients • signal transduction • spindle • structure • T • transport • two-component systems • V • vacuole • vesicle •
First cell division: single diploid parent cell successively passes through:
1. prophase 1
2. metaphase 1
3. anaphase 1
4. telophase 1 & prophase 2
Second cell division
5. metaphase 2
6. anaphase 2
7. telophase 2,
producing 4 haploid daughter cells.
(image mitosis vs meiosis)
Recombination provides a mechanism for genetic variability and is a mechanism of biological evolution. Recombination between homologous chromosomes in meiosis I involves the formation and repair of double strand breaks (DSBs), and meiosis I employs the same enzymes as does DSB repair. Many biologists consider the main function of sexual reproduction is to provide this mechanism for maintaining the integrity of the genome.
• A • adhesion • C • cell membranes • cellular adhesion molecules • cellular signal transduction • centrioles • chemotaxis • chloroplast • cilia & flagella • communication • concentration gradients • cytokine receptors • cytoplasm • cytoskeleton • E • energy transducers • endoplasmic reticulum • endosomes • exosome • F • flagella & cilia • G • Golgi apparatus • GPCRs • H • hormones • I • ion channels • L • lysosome • M • meiosis • microtubules • mitosis • mitochondrion • N • Nitric Oxide • neurotransmission • neuronal interconnections • nuclear membrane • nuclear pore • P • pinocytosis • proteasome • pumps • R • receptor proteins • receptor-mediated endocytosis • S • second messengers • signaling gradients • signal transduction • spindle • structure • T • transport • two-component systems • V • vacuole • vesicle •