1. Introduction
Meiosis is a special type of cell division that creates sex cells (sperm cells or egg cells) with half the chromosome number of body cells. As these sex cells (or gametes) are created, an enormous amount of shuffling of genes occurs, making meiosis a powerful engine for creating variation within sexually reproducing, eukaryotic organisms.
In what follows, we’ll start by looking at a cell’s chromosome number and its relationship to meiosis. Then we’ll turn our attention to how meiosis creates variation.
Meiosis evolved from (or with) mitosis and uses many of the same cellular mechanisms. If you need an easy review of Mitosis, consider listening to my Mitosis Rap and trying my mitosis quizzes before proceeding with what’s below. Also, if you want to watch my music video about meiosis before interacting with the material below, then click here for my Meiosis Song.
A typical lab relating to meiosis and recombination is the Sordaria lab. Here’s a piece with my reflections on the underlying biology of this lab.
2. Understanding Chromosome Number
Eukaryotic chromosomes are linear packages of DNA (with the DNA tightly coiled around various proteins). The cells in your body (excluding sperm cells or egg cells) have two sets of chromosomes: one inherited through your mother’s egg, and one through your father’s sperm. These two sets came together during fertilization, and all the cells of your body are descended from that one fertilized egg cell.
Humans have 23 pairs of chromosomes, for a total of 46. There’s nothing important or significant about the chromosome number of a species. More is not better. Chimpanzees have 48 chromosomes. Dogs have 78. Pineapples have 50. Fruit flies have 8. Notice that because there are two sets, the total chromosome number is always an even number.
The word that describes having two sets of chromosomes in each cell is diploid. Focus on the prefix di (as in dialogue, where two people speak). You can also represent this with a mathematical symbol. If n stands for each set of chromosomes, then a diploid cell has 2n chromosomes.
You can see this in the image below, which is called a karyotype. The image shows the chromosomes in a human diploid cell, artificially paired up by size and staining pattern. In each of the pairs below, one of the chromosomes is from the mother, and the other is from the father.
It’s essential to note that the chromosomes in each pair are not identical. They contain the same genes for the same proteins and RNAs in the same order, but the actual DNA sequences in each gene might be different. The word for this kind of pair is homologous. It means “sharing the same pattern.” As Richard Dawkins explains, it’s as if both of your parents gave you, as part of your inheritance, a 23-volume set of recipes. The recipe books from your mother would be numbered 1a, 2a, 3a, and so on; the ones from your father would be numbered 1b, 2b, and 3b. If you opened volumes 1a and 1b to page 73, you’d find recipes for the same dish. Those recipes might be the same, but they can also differ. If this were a recipe for tomato sauce, your mother’s recipe might have a bit more onion. Your father’s recipe might have more oregano. To return to cells and biology, the genes are the same, but there might be alternative versions of these genes, with distinct sequences of DNA nucleotides. Alternative versions of genes are called alleles, and we’ll see the consequences of differences in alleles when we study genetics in an upcoming module.
The diploid cells in your body fall into two categories. The vast majority of these cells are somatic cells. Somatic cells are all the cells in your body that are doing the job of keeping you alive. They’re the cells making up your brain, muscles, liver, kidney, skin, etc. These somatic cells were created through mitosis, during which a diploid cell cloned itself to create diploid daughter cells. The only diploid cells that aren’t somatic cells are germ cells. Germ cells are specialized cells in the ovaries or testes that go through meiosis to create gametes (sperm cells or egg cells).
While our somatic and germ cells are diploid, our gametes have only one chromosome set. Think about it. We have two sets of chromosomes. Since we inherit half of our chromosomes from our mothers and the other half from our fathers, then we can only get one set from each parent. The gametes (sperm cells and egg cells) deliver that one set. A cell with one set of chromosomes is said to be haploid. Mathematically, this is represented by the symbol n. In humans, the haploid number of chromosomes (n) is 23 and the diploid number (2n) is 46. Fruit flies have four pairs of chromosomes, so their haploid number is 4. In dogs, with 39 pairs of chromosomes, the haploid number is 39.
In what follows, the meiotic cell division that germ cells undergo will be our focus. But first, a few flashcards about what you just read.
3. Flashcards: Key Meiosis Terms
[qdeck qrecord_id=”sciencemusicvideosMeister1961-meiosis: key meiosis terms”]
[h]Flashcards: Key Meiosis Terms
[i]Chromosomes and Chromosome Number in Sexually Reproducing Organisms
[start]
[q] What’s a chromosome?
[a]Chromosomes are linear packages of DNA, with the DNA tightly coiled around proteins. Chromosomes carry genetic information.
[q] Define gamete, and describe a gamete’s chromosomal condition.
[a]Gametes are sex cells. The term encompasses both sperm cells and egg cells. Gametes are haploid: they have only one chromosome set.
[q]What does haploid mean?
[a]Haploid means one chromosome set.
[q]What does diploid mean?
[a]Diploid means two chromosome sets.
[q]What are homologous chromosomes?
[a]Homologous chromosomes are chromosomes that are matched in terms of size, banding pattern, and above all information. In each homologous pair, one member of the pair comes from your mother, and the other from your father. The genes in these homologs are the same, in the same order, but the actual genetic information (in the sequence of DNA) can vary. In other words, the genes are the same, but the alleles might vary.
[q]Define “somatic cell,” describe a somatic cell’s chromosomal condition, and give some examples.
[a]Somatic cells are body cells. They’re diploid (with two chromosome sets). Examples are any cell in the body (liver, heart, skin, pancreatic, muscle, etc.) except for egg or sperm cells.
[q]What’s a karyotype?
[a]A karyotype is an image that’s made by matching up chromosomes by size and banding pattern.
[q]What are germ cells? What’s their chromosomal condition? What kind of cell division do they undergo?
[a]Germ cells are the diploid cells in the testes or ovaries that go through meiosis to produce haploid gametes.
[x][restart]
[/qdeck]
4. Quiz: Basic Concepts of Meiosis
[qwiz style = “border: 3px solid black; ” qrecord_id=”sciencemusicvideosMeister1961-meiosis: basic concepts”]
[h] Meiosis: Basic Concepts
[i] Here’s how the quiz works:
- Each question is multiple-choice, but the entire quiz is like a series of flashcards.
- If you get the question right, it comes off the deck.
- If you get the question wrong, it goes to the bottom of the deck, so you can try it again.
[q multiple_choice=”true”] The word for ‘two chromosome sets’ is
[c]IGRpcG xvaWQ=[Qq]
[f]IENvcnJlY3QuIOKAmERpcGxvaWTigJkgbWVhbnMg4oCYdHdvIGNocm9tb3NvbWUgc2V0cy7igJk=[Qq]
[c]IGhhcGxvaWQ=[Qq]
[f]IE5vLiDigJhIYXBsb2lk4oCZIG1lYW5zIOKAmGEgc2luZ2xlIHNldCBvZiBjaHJvbW9zb21lcy7igJkgQSBwcmVmaXggdXNlZCB0byBpbmRpY2F0ZSDigJh0d2/igJkgaXMg4oCYZGku4oCZIFJlbWVtYmVyIHRoYXQgdGhlIG5leHQgdGltZSB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24u[Qq]
[c]IHRyaXBsb2lk[Qq]
[f]IE5vLiDigJhUcmlwbG9pZOKAmSBoYXMgdGhlIHByZWZpeCDigJh0cmks4oCZIHdoaWNoIG1lYW5zIOKAmHRocmVlLuKAmSBBIHByZWZpeCB1c2VkIHRvIGluZGljYXRlIOKAmHR3b+KAmSBpcyDigJhkaS7igJkgUmVtZW1iZXIgdGhhdCB0aGUgbmV4dCB0aW1lIHlvdSBzZWUgdGhpcyBxdWVzdGlvbi4=
Cg==[Qq]
[q multiple_choice=”true”] The somatic and germ cells of adult animals (including humans) have
[c]IG9uZSBzZXQgb2YgY2hyb21vc29tZXM=[Qq]
[f]IE5vLiBUaGluayBvZiBpdCB0aGlzIHdheS4gSW4gYW4gYWR1bHQgYW5pbWFsLCBvbmUgc2V0IG9mIGNocm9tb3NvbWVzIHdhcyBjb250cmlidXRlZCBieSB0aGUgbW90aGVyLCB0aGUgb3RoZXIgYnkgdGhlIGZhdGhlci4gSWYgeW91IGFkZCB0aGVtIHVwLCB5b3UgaGF2ZSBob3cgbWFueSBzZXRzPw==[Qq]
[c]IHR3byBzZXRzIG9m IGNocm9tb3NvbWVz[Qq]
[f]IEV4YWN0bHkuIEFkdWx0IGFuaW1hbHMgaGF2ZSB0d28gc2V0cyBvZiBjaHJvbW9zb21lcywgd2l0aCBvbmUgc2V0IGNvbnRyaWJ1dGVkIGJ5IHRoZSBtb3RoZXIsIGFuZCB0aGUgb3RoZXIgc2V0IGNvbnRyaWJ1dGVkIGJ5IHRoZSBmYXRoZXIu[Qq]
[c]IHRocmVlIHNldHMgb2YgY2hyb21vc29tZXM=[Qq]
[f]IE5vLiBUaGluayBvZiBpdCB0aGlzIHdheS4gSW4gYW4gYWR1bHQgYW5pbWFsLCBvbmUgc2V0IG9mIGNocm9tb3NvbWVzIHdhcyBjb250cmlidXRlZCBieSB0aGUgbW90aGVyLCB0aGUgb3RoZXIgYnkgdGhlIGZhdGhlci4gSWYgeW91IGFkZCB0aGVtIHVwLCB5b3UgaGF2ZSBob3cgbWFueSBzZXRzPw==[Qq]
[c]IGZvdXIgc2V0cyBvZiBjaHJvbW9zb21lcy4=[Qq]
[f]IE5vLiBUaGluayBvZiBpdCB0aGlzIHdheS4gSW4gYW4gYWR1bHQgYW5pbWFsLCBvbmUgc2V0IG9mIGNocm9tb3NvbWVzIHdhcyBjb250cmlidXRlZCBieSB0aGUgbW90aGVyLCB0aGUgb3RoZXIgYnkgdGhlIGZhdGhlci4gSWYgeW91IGFkZCB0aGVtIHVwLCB5b3UgaGF2ZSBob3cgbWFueSBzZXRzPw==
Cg==[Qq]
[q multiple_choice=”true”] The word for ‘one chromosome set’ is
[c]IGRpcGxvaWQ=[Qq]
[f]IE5vLiAmIzgyMjA7RGlwbG9pZCYjODIyMTsgbWVhbnMgJiM4MjIwO3R3byBjaHJvbW9zb21lIHNldHMuJiM4MjIxOyBIZXJl4oCZcyBhIGhpbnQuIElmIHlvdSBoYXZlIG9uZSBjaHJvbW9zb21lIHNldCwgdGhlbiB5b3UgaGF2ZSBoYWxmIHRoZSBudW1iZXIgb2YgY2hyb21vc29tZXMgYXMgYW4gYWR1bHQgb3JnYW5pc20gd2l0aCB0d28gc2V0cy4gVGhlIHdvcmQg4oCYaGFsZuKAmSBiZWdpbnMgd2l0aCDigJhILUEu4oCZIFdoaWNoIG9mIHRoZXNlIGNob2ljZXMgYWxzbyBiZWdpbnMgd2l0aCDigJhILUE/4oCZ[Qq]
[c]IGhhcG xvaWQ=[Qq]
[f]IFllcy4gJiM4MjIwO0hhcGxvaWQmIzgyMjE7IG1lYW5zICYjODIyMDthIHNpbmdsZSBzZXQgb2YgY2hyb21vc29tZXMuJiM4MjIxOw==[Qq]
[c]IHRyaXBsb2lk[Qq]
[f]IE5vLiDigJhUcmlwbG9pZOKAmSBoYXMgdGhlIHByZWZpeCDigJh0cmks4oCZIHdoaWNoIG1lYW5zIOKAmHRocmVlLuKAmSBIZXJl4oCZcyBhIGhpbnQuIElmIHlvdSBoYXZlIG9uZSBjaHJvbW9zb21lIHNldCwgdGhlbiB5b3UgaGF2ZSBoYWxmIHRoZSBudW1iZXIgb2YgY2hyb21vc29tZXMgYXMgYW4gYWR1bHQgb3JnYW5pc20gd2l0aCB0d28gc2V0cy4gVGhlIHdvcmQg4oCYaGFsZuKAmSBiZWdpbnMgd2l0aCDigJhILUEu4oCZIFdoaWNoIG9mIHRoZXNlIGNob2ljZXMgYWxzbyBiZWdpbnMgd2l0aCDigJhILUE/4oCZ
Cg==[Qq]
[q multiple_choice=”true”] If you wanted to use one word to refer to both sperm cells and egg cells, the best word to use would be
[c]IGRpcGxvaWRz[Qq]
[f]IE5vLiDigJhEaXBsb2lk4oCZIG1lYW5zIOKAmHR3byBjaHJvbW9zb21lIHNldHMuIENob29zZSBhbm90aGVyIHRlcm0gbmV4dCB0aW1lLg==[Qq]
[c]IHNleHkgY2VsbHM=[Qq]
[f]IE5vLiDigJhTZXggY2VsbHPigJkgbWlnaHQgYmUgYSBnb29kIHJlc3BvbnNlLCBidXQg4oCYc2V4eT/igJkgQ2hvb3NlIGFub3RoZXIgd29yZCBuZXh0IHRpbWUu[Qq]
[c]IG92YXJ5IGNlbGxz[Qq]
[f]IE5vLiBFZ2cgY2VsbHMgYXJlIG1hZGUgaW4gb3ZhcmllcywgYnV0IHRoZXJl4oCZcyBhIHNpbmdsZSB3b3JkIHRoYXQgY292ZXJzIGJvdGggc3Blcm0gY2VsbHMgYW5kIGVnZyBjZWxscy4gTWFrZSBhbm90aGVyIGNob2ljZSBuZXh0IHRpbWUgeW91IHNlZSB0aGlzIHF1ZXN0aW9uLg==[Qq]
[c]IGdhbW V0ZXM=[Qq]
[f]IEV4Y2VsbGVudC7CoFRoZSB3b3JkIGdhbWV0ZSBtZWFucyDigJhzZXggY2VsbCzigJkgYW5kIHJlZmVycyB0byBib3RoIGVnZyBhbmQgc3Blcm0gY2VsbHMu
Cg==[Qq]
[q multiple_choice=”true”] Chromosomes with the same size, appearance, and pattern of genes, such as the ones shown here, are said to be
[c]IHN5bm9ueW1vdXM=[Qq]
[f]IE5vLiDigJjigJlTeW5vbnltb3Vz4oCZIHJlZmVycyB0byB3b3JkcyB0aGF0IGhhdmUgdGhlIHNhbWUgbWVhbmluZy4gWW914oCZcmUgbG9va2luZyBmb3IgYSBtb3JlIHNwZWNpYWxpemVkIHRlcm0gdXNlZCBtb3N0bHkgaW4gZ2VuZXRpY3MgYW5kIGV2b2x1dGlvbmFyeSBiaW9sb2d5Lg==[Qq]
[c]IGlkZW50aWNhbA==[Qq]
[f]IE5vLiBBIGtleSBwb2ludCBpcyB0aGF0IHdoaWxlIHRoZXNlIGNocm9tb3NvbWVzIGFyZSB2ZXJ5IHNpbWlsYXIsIHRoZXkgYXJlIE5PVCBpZGVudGljYWwuIFlvdeKAmXJlIGxvb2tpbmcgZm9yIGEgc29tZXdoYXQgc3BlY2lhbGl6ZWQgdGVybSB1c2VkIG1vc3RseSBpbiBnZW5ldGljcyBhbmQgZXZvbHV0aW9uYXJ5IGJpb2xvZ3ku[Qq]
[c]IGhvbW9s b2dvdXM=[Qq]
[f]IENvcnJlY3QuIENocm9tb3NvbWVzIHdpdGggdGhlIHNhbWUgc2l6ZSwgYXBwZWFyYW5jZSwgYW5kIHBhdHRlcm4gb2YgZ2VuZXMsIGFyZSBzYWlkIHRvIGJlIOKAmGhvbW9sb2dvdXMu4oCZ[Qq]
[c]IHNpbWlsYXI=[Qq]
[f]IE5vLiBUaGVzZSBjaHJvbW9zb21lcyBhcmUsIGluZGVlZCwgc2ltaWxhci4gQnV0IHlvdeKAmXJlIGxvb2tpbmcgZm9yIGEgc29tZXdoYXQgc3BlY2lhbGl6ZWQgdGVybSB1c2VkIG1vc3RseSBpbiBnZW5ldGljcyBhbmQgZXZvbHV0aW9uYXJ5IGJpb2xvZ3ku
Cg==[Qq]
[q multiple_choice=”true”] The cells that make up your kidneys, skin, and brain are
[c]IGRpcG xvaWQ=[Qq]
[f]IFRoYXTigJlzIHJpZ2h0LiBBbGwgb2YgdGhlc2UgY2VsbHMgYXJlIA==c29tYXRpYw==IGNlbGxzLiBTb21hdGljIGNlbGxzIGFyZSBkaXBsb2lkLCB3aXRoIHR3byBjaHJvbW9zb21lIHNldHMu[Qq]
[c]IGhhcGxvaWQ=[Qq]
[f]IE5vLiBUaGUgb25seSBjZWxscyBpbiB5b3VyIGJvZHkgdGhhdCBhcmUgaGFwbG9pZCBhcmUgeW91ciBnYW1ldGVzIChzcGVybSBjZWxscyBvciBlZ2cgY2VsbHMsIGRlcGVuZGluZyBvbiB5b3VyIHNleCkuIEhlcmXigJlzIGEgaGludDogU29tYXRpYyBjZWxscyBhcmUgdGhlIGNlbGxzIHRoYXQgbWFrZSB1cCB5b3VyIGJvZHkuIFRoZXnigJlyZSBhbGwgZGVzY2VuZGVkIGZyb20gYSB6eWdvdGUsIHdoaWNoIGlzIGZvcm1lZCB3aGVuIGEgaGFwbG9pZCBzcGVybSBmZXJ0aWxpemVkIGEgaGFwbG9pZCBlZ2cuIElmIHlvdSBjb21iaW5lIHR3byBoYXBsb2lkIGNlbGxzLCB0aGUgcmVzdWx0aW5nIGNlbGwgaXMmIzgyMzA7[Qq]
[c]IHRyaXBsb2lk[Qq]
[f]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
Cg==[Qq]
[q multiple_choice=”true”] Human somatic cells have ______ chromosomes.
[c]IDY5[Qq]
[f]IE5vLiA2OSB3b3VsZCBiZSBlcXVpdmFsZW50IHRvIHRocmVlIGNocm9tb3NvbWUgc2V0cy4gU29tYXRpYyBjZWxscyAodGhlIGNlbGxzIHRoYXQgbWFrZSB1cCB0aGUgdGlzc3VlcyBvZiB5b3VyIGJvZHkpIGhhdmUgdHdvIGNocm9tb3NvbWUgc2V0cy4gRG8gYSBsaXR0bGUgbWF0aCwgZmlndXJlIG91dCB0aGUgbnVtYmVyIG9mIGNocm9tb3NvbWVzIGluIG9uZSBjaHJvbW9zb21lIHNldCwgbXVsdGlwbHkgYnkgdHdvLCBhbmQgbmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyLg==[Qq]
[c]IDIz[Qq]
[f]IE5vLiBUaGUgb25seSBjZWxscyBpbiB5b3VyIGJvZHkgdGhhdCBoYXZlIDIzIGNocm9tb3NvbWVzIGFyZSB5b3VyIGdhbWV0ZXMgKHNwZXJtIGNlbGxzIG9yIGVnZyBjZWxscywgZGVwZW5kaW5nIG9uIHlvdXIgc2V4KS4gSGVyZeKAmXMgYSBoaW50OiBTb21hdGljIGNlbGxzIGFyZSB0aGUgY2VsbHMgdGhhdCBtYWtlIHVwIHlvdXIgYm9keS4gVGhleeKAmXJlIGFsbCBkZXNjZW5kZWQgZnJvbSBhIHp5Z290ZSwgd2hpY2ggaXMgZm9ybWVkIHdoZW4gYQ==wqAgc3Blcm0gd2l0aCAyMyBjaHJvbW9zb21lcyBmZXJ0aWxpemVkIGFuIGVnZywgYWxzbyB3aXRoIDIzIGNocm9tb3NvbWVzLiBJZiB5b3UgY29tYmluZSB0aGVzZSB0d28gc2V0cywgd2hhdOKAmXMgdGhlIHRvdGFsPw==[Qq]
[c]ID Q2[Qq]
[f]IFRoYXTigJlzIGNvcnJlY3QuIEh1bWFuIHNvbWF0aWMgY2VsbHMgaGF2ZSA0NiBjaHJvbW9zb21lcy4=
Cg==[Qq]
[q multiple_choice=”true”] This image comes from a cell of a human male. Which of the terms below best describes the chromosomal condition of this cell?
[c]IGhhcGxvaWQ=[Qq]
[f]IE5vLiDigJhIYXBsb2lk4oCZIG1lYW5zIOKAmG9uZSBjaHJvbW9zb21lIHNldC7igJkgWW91IGNhbiBzZWUgdGhhdCB0aGUgY2hyb21vc29tZXMgaW4gdGhpcyBpbWFnZSBhcmUgaW4gbWF0Y2hlZCBwYWlycywgd2hpY2ggbWVhbnMgdGhhdCB0aGVyZSBhcmUgdHdvIGNocm9tb3NvbWUgc2V0cy4gTmV4dCB0aW1lLCBzZWxlY3QgYSB0ZXJtIHRoYXQgaGFzIHRoZSBwcmVmaXggdGhhdCBtZWFucyDigJh0d28s4oCZIGFzIGluIOKAmGRpc2FjY2hhcmlkZS7igJk=[Qq]
[c]IGRpcG xvaWQ=[Qq]
[f]IFllcy4gVGhlcmUgYXJlIHR3byBjaHJvbW9zb21lIHNldHMsIHdoaWNoIG1lYW5zIHRoYXQgdGhlIGNlbGwgaXMgZGlwbG9pZC4=[Qq]
[c]IHRyaXBsb2lk[Qq]
[f]IE5vLiDigJhUcmlwbG9pZOKAmSBoYXMgdGhlIHByZWZpeCDigJh0cmks4oCZIHdoaWNoIG1lYW5zIOKAmHRocmVlLuKAmSBZb3UgY2FuIHNlZSB0aGF0IHRoZSBjaHJvbW9zb21lcyBpbiB0aGlzIGltYWdlIGFyZSBpbiBtYXRjaGVkIHBhaXJzLCB3aGljaCBtZWFucyB0aGF0IHRoZXJlIGFyZSB0d28gY2hyb21vc29tZSBzZXRzLiBOZXh0IHRpbWUsIHNlbGVjdCBhIHRlcm0gdGhhdCBoYXMgdGhlIHByZWZpeCB0aGF0IG1lYW5zIOKAmHR3byzigJkgYXMgaW4g4oCYZGlzYWNjaGFyaWRlLuKAmQ==
Cg==[Qq]
[q multiple_choice=”true”] In human gametes, the chromosome number is
[c]IDY5[Qq]
[f]IE5vLiA2OSB3b3VsZCBiZSBlcXVpdmFsZW50IHRvIHRocmVlIGNocm9tb3NvbWUgc2V0cy4gR2FtZXRlcyAoc3Blcm0gY2VsbHMgb3IgZWdnIGNlbGxzKSBoYXZlIG9uZSBjaHJvbW9zb21lIHNldC4gRG8gYSBsaXR0bGUgbWF0aCBhbmQgbmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyLg==[Qq]
[c]ID Iz[Qq]
[f]IEV4Y2VsbGVudC4gR2FtZXRlcyBoYXZlIDIzIGNocm9tb3NvbWVzLg==[Qq]
[c]IDQ2[Qq]
[f]IE5vLiA0NiBpcyB0aGUgbnVtYmVyIG9mIGNocm9tb3NvbWVzIGZvdW5kIGluIHNvbWF0aWMgY2VsbHMgKHRoZSBjZWxscyBpbiBhbGwgb2YgeW91ciBib2R5IHRpc3N1ZXMsIGV4Y2VwdCBmb3Igc3Blcm0gYW5kIGVnZyBjZWxscykuIENlbGxzIHdpdGggNDYgY2hyb21vc29tZXMgYXJlIGRpcGxvaWQsIG1lYW5pbmcgdGhhdCB0aGV5IGhhdmUgdHdvIGNocm9tb3NvbWUgc2V0cy4gR2FtZXRlcyBoYXZlIG9uZSBjaHJvbW9zb21lIHNldC4gRG8gYSBsaXR0bGUgbWF0aCBhbmQgbmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyLg==[Qq]
[x]
[restart]
[/qwiz]
Links
- Continue to Meiosis, Part 2 (Meiosis 1 v. Meiosis 2)
- Return to the Meiosis Main Menu
- Watch the Meiosis Music Video