Click here for a Meiosis Student Learning Guide

1. Introduction

In the previous tutorial, we talked about the basics of meiosis. In this tutorial, we’ll look at the life cycle of sexually reproducing organisms, and how the creation of haploid cells involves two cell divisions.

2. Haploid cells, Diploid cells, and the Life Cycle of Sexually Reproducing Organisms

Now let’s use this meiosis-related vocabulary to understand the haploid and diploid moments that occur in the human life cycle.”

We’ll start at the bottom left, where you see an adult female (1a) and an adult male (1b). All of their cells, except for their gametes, are diploid.

“3” represents the process of meiosis. During meiosis, germ cells in the ovaries (2a) or testes (2b) divide in a way that reduces the chromosome number from diploid (2 sets) to haploid (one set). The results are male and female gametes: sperm (4b) or egg cells (4a).

“5” represents fertilization. The sperm fuses with the egg. This creates a fertilized egg, or zygote (6). Because the zygote has received one set of chromosomes from the egg, and one set of chromosomes from the sperm, it has two sets of chromosomes, making it diploid.

“7” represents the processes of mitotic cell division, growth, and development. The result is a reproductively mature male or female, able to produce gametes and pass his or her genes on to the next generation.

Got it? Try this quiz. Note that, by design, I’ve changed the numbering scheme in the diagram. That difficulty will improve memory.

3. Quiz: The Life Cycle of Sexually Reproducing Organisms

[qwiz qrecord_id=”sciencemusicvideosMeister1961-meiosis: sexual life cycle”]

[h]The life cycle of sexually reproducing organisms

[i]

[q labels = “top”]

 

[l]adult female

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]adult male

[fx] No. Please try again.

[f*] Good!

[l]fertilization

[fx] No. Please try again.

[f*] Excellent!

[l]egg

[fx] No. Please try again.

[f*] Correct!

[l]growth and development

[fx] No. Please try again.

[f*] Excellent!

[l]meiosis

[fx] No. Please try again.

[f*] Great!

[l]ovary

[fx] No. Please try again.

[f*] Correct!

[l]sperm

[fx] No. Please try again.

[f*] Great!

[l]testes

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]zygote

[fx] No, that’s not correct. Please try again.

[f*] Good!

[q] In the diagram below, which number represents fertilization?

[c]IEk=

[c]IE lJ

[c]IElJSQ==

[f]IE5vLiBSb21hbiBudW1lcmFsIEkgc2hvd3MgY2VsbHMgZm9ybWVkIGZyb20gb3ZhcmllcyBhbmQgdGVzdGVzLiBGZXJ0aWxpemF0aW9uIGlzIHdoZW4gdHdvIGdhbWV0ZXMgZnVzZSB0b2dldGhlciB0byBiZWNvbWUgYSB6eWdvdGUuIFdoZXJlIGluIHRoZSBkaWFncmFtIGRvIHlvdSBzZWUgdHdvIGNlbGxzIGJlY29taW5nIG9uZT8=

[f]IEV4YWN0bHkuIElJIHNob3dzIGEgc3Blcm0gYW5kIGFuIGVnZyBjZWxsIGZ1c2luZyB0b2dldGhlciB0byBiZWNvbWUgYSB6eWdvdGUu

[f]IE5vLiBJSUkgc2hvd3MgYSB6eWdvdGUgZ3Jvd2luZyBhbmQgZGV2ZWxvcGluZyB0byBiZWNvbWUgYW4gYWR1bHQgb3JnYW5pc20uIEZlcnRpbGl6YXRpb24gaXMgd2hlbiB0d28gZ2FtZXRlcyBmdXNlIHRvZ2V0aGVyIHRvIGJlY29tZSBhIHp5Z290ZS4gV2hlcmUgaW4gdGhlIGRpYWdyYW0gZG8geW91IHNlZSB0d28gY2VsbHMgYmVjb21pbmcgb25lPzwvcD4KPHAgY2xhc3M9InAxIj4=

[q] In the diagram below, which number represents meiosis?

[c]IE k=

[c]IElJ

[c]IElJSQ==

[f]IFllcy4gUm9tYW4gbnVtZXJhbCBJIHNob3dzIGEgc3Blcm0gYW5kIGFuIGVnZyBjZWxsIGZvcm1pbmcgZnJvbSB0ZXN0ZXMgYW5kIG92YXJpZXMuIFRoaXMgaXMgZXhhY3RseSB3aGF0IGhhcHBlbnMgaW4gbWVpb3Npcy4=

[f]IE5vLiBJSSBpcyBzaG93aW5nIGFuIGVnZyBhbmQgYSBzcGVybSBjZWxsIGZ1c2luZyB0b2dldGhlciB0byBmb3JtIGEgenlnb3RlLCBhIHByb2Nlc3Mga25vd24gYXMgZmVydGlsaXphdGlvbi4gTmV4dCB0aW1lLCBjaG9vc2UgYSBwcm9jZXNzIHRoYXQgc2hvd3MgZm9ybWF0aW9uIG9mIGVnZyBjZWxscyBvciBzcGVybSBjZWxscyAod2hpY2ggaXMgd2hhdCBoYXBwZW5zIGR1cmluZyBtZWlvc2lzKS4=

[f]IE5vLiBJSUkgc2hvd3MgYSB6eWdvdGUgZ3Jvd2luZyBhbmQgZGV2ZWxvcGluZyB0byBiZWNvbWUgYW4gYWR1bHQgb3JnYW5pc20uIE5leHQgdGltZSwgY2hvb3NlIGEgcHJvY2VzcyB0aGF0IHNob3dzIGZvcm1hdGlvbiBvZiBlZ2cgY2VsbHMgb3Igc3Blcm0gY2VsbHMgKHdoaWNoIGlzIHdoYXQgaGFwcGVucyBkdXJpbmcgbWVpb3NpcykuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which number represents mitosis, growth, and development?

[c]IEk=

[c]IElJ

[c]IElJ SQ==

[f]IE5vLiBSb21hbiBudW1lcmFsIEkgc2hvd3MgYSBzcGVybSBhbmQgYW4gZWdnIGNlbGwgZm9ybWluZyBmcm9tIHRlc3RlcyBhbmQgb3Zhcmllcy4gVGhpcyBpcyB3aGF0IGhhcHBlbnMgaW4gbWVpb3Npcy4gTmV4dCB0aW1lLCBsb29rIGZvciBhIHByb2Nlc3MgdGhhdCBzaG93cyBhIGNoYW5nZSBmcm9tIGEgc2luZ2xlIGNlbGwgdG8gYSBtdWx0aWNlbGx1bGFyIGFkdWx0LiBUaGlzIGNoYW5nZSB3b3VsZCBjb21lIGFib3V0IHRocm91Z2ggcmVwZWF0ZWQgcm91bmRzIG9mIG1pdG9zaXMsIGNlbGwgZ3Jvd3RoLCBhbmQgY2VsbCBkaWZmZXJlbnRpYXRpb24gYXMgdGhlIG9yZ2FuaXNtIGRldmVsb3BzLg==

[f]IE5vLiBJSSBpcyBzaG93aW5nIGFuIGVnZyBhbmQgYSBzcGVybSBjZWxsIGZ1c2luZyB0b2dldGhlciB0byBmb3JtIGEgenlnb3RlLCBhIHByb2Nlc3Mga25vd24gYXMgZmVydGlsaXphdGlvbi4gTmV4dCB0aW1lLCBsb29rIGZvciBhIHByb2Nlc3MgdGhhdCBzaG93cyBhIGNoYW5nZSBmcm9tIGEgc2luZ2xlIGNlbGwgdG8gYSBtdWx0aWNlbGx1bGFyIGFkdWx0LiBUaGlzIGNoYW5nZSB3b3VsZCBjb21lIGFib3V0IHRocm91Z2ggcmVwZWF0ZWQgcm91bmRzIG9mIG1pdG9zaXMsIGNlbGwgZ3Jvd3RoLCBhbmQgY2VsbCBkaWZmZXJlbnRpYXRpb24gYXMgdGhlIG9yZ2FuaXNtIGRldmVsb3BzLg==

[f]IFBlcmZlY3QuIElJSSBzaG93cyBhIHp5Z290ZSBncm93aW5nIGFuZCBkZXZlbG9waW5nIHRvIGJlY29tZSBhbiBhZHVsdCBvcmdhbmlzbS4gVGhpcyBjaGFuZ2Ugd291bGQgY29tZSBhYm91dCB0aHJvdWdoIHJlcGVhdGVkIHJvdW5kcyBvZiBtaXRvc2lzLCBjZWxsIGdyb3d0aCwgYW5kIGNlbGwgZGlmZmVyZW50aWF0aW9uIGFzIHRoZSBvcmdhbmlzbSBkZXZlbG9wcy48L3A+CjxwIGNsYXNzPSJwMSI+

[q] In the diagram below, which structure or cell would be haploid?

[c]IDE=

[c]ID Q=

[c]IDU=

[f]IE5vLjxzcGFuIGNsYXNzPSJBcHBsZS1jb252ZXJ0ZWQtc3BhY2UiPsKgIDwvc3Bhbj5OdW1iZXIgMSBpcyBhbiBvdmFyeS4gT3ZhcmlhbiB0aXNzdWUsIGxpa2UgYWxsIHNvbWF0aWMgdGlzc3VlLCBpcyBkaXBsb2lkLiBIb3dldmVyLCBzb21lIGNlbGxzIGluIGFuIG92YXJ5IGdvIHRocm91Z2ggbWVpb3NpcyB0byBiZWNvbWUgYSBoYXBsb2lkIGVnZy4gTmV4dCB0aW1lLCBtYWtlIGEgZGlmZmVyZW50IGNob2ljZS4=

[f]IENvcnJlY3QuIE51bWJlciA0IGlzIGFuIGVnZy4gRWdncyBhcmUgaGFwbG9pZCBjZWxscyB0aGF0IHJlc3VsdCBmcm9tIG1laW9zaXMu

[f]IE5vLiBOdW1iZXIgNSBpcyBhIHp5Z290ZS4gQSB6eWdvdGUgaXMgYSBmZXJ0aWxpemVkIGVnZywgd2l0aCB0d28gc2V0cyBvZiBjaHJvbW9zb21lcywgbWFraW5nIGl0IGRpcGxvaWQuIE5leHQgdGltZSwgbWFrZSBhIGRpZmZlcmVudCBjaG9pY2UuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, is the cell at number 5 haploid or diploid?

[c]IGRpcG xvaWQ=

[c]IGhhcGxvaWQ=

[f]IFllcy4gVGhlIGNlbGwgYXQgbnVtYmVyIDUgaXMgYSB6eWdvdGUuIEEgenlnb3RlIGlzIGEgZmVydGlsaXplZCBlZ2csIHdpdGggdHdvIHNldHMgb2YgY2hyb21vc29tZXMsIG1ha2luZyBpdCBkaXBsb2lkLg==

[f]IE5vLiBUaGUgY2VsbCBhdCBudW1iZXIgNSBpcyBhIHp5Z290ZS4gQSB6eWdvdGUgaXMgYSBmZXJ0aWxpemVkIGVnZywgd2l0aCB0d28gc2V0cyBvZiBjaHJvbW9zb21lcywgbWFraW5nIGl0IGRpcGxvaWQuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which structure is a zygote?

[c]IDE=

[c]IDI=

[c]IDM=

[c]IDQ=

[c]ID U=

[f]IE5vLiBOdW1iZXIgMSBpcyB0aGUgb3ZhcnkuIEEgenlnb3RlIGlzIGEgZmVydGlsaXplZCBlZ2csIGFuZCBpdCBjb21lcyBhYm91dCB3aGVuIGEgc3Blcm0gY2VsbCBmZXJ0aWxpemVzIGFuIGVnZy4gV2hlcmUgaW4gdGhlIGRpYWdyYW0gZG8geW91IHNlZSB0aGUgY2VsbCB0aGF0IGZvcm1zIHdoZW4gdHdvIGNlbGxzIGZ1c2UgdG9nZXRoZXIgdG8gYmVjb21lIG9uZT8=

[f]IE5vLiBOdW1iZXIgMiBpcyBhIHRlc3RpcyAoc2luZ3VsYXIgZm9yIHRlc3RlcykuIEEgenlnb3RlIGlzIGEgZmVydGlsaXplZCBlZ2csIGFuZCBpdCBjb21lcyBhYm91dCB3aGVuIGEgc3Blcm0gY2VsbCBmZXJ0aWxpemVzIGFuIGVnZy4gV2hlcmUgaW4gdGhlIGRpYWdyYW0gZG8geW91IHNlZSB0aGUgY2VsbCB0aGF0IGZvcm1zIHdoZW4gdHdvIGNlbGxzIGZ1c2UgdG9nZXRoZXIgdG8gYmVjb21lIG9uZT8=

[f]IE5vLiBOdW1iZXIgMyBpcyBhIHNwZXJtIGNlbGwuIEEgenlnb3RlIGlzIGEgZmVydGlsaXplZCBlZ2csIGFuZCBpdCBjb21lcyBhYm91dCB3aGVuIGEgc3Blcm0gY2VsbCBmZXJ0aWxpemVzIGFuIGVnZy4gV2hlcmUgaW4gdGhlIGRpYWdyYW0gZG8geW91IHNlZSB0aGUgY2VsbCB0aGF0IGZvcm1zIHdoZW4gdHdvIGNlbGxzIGZ1c2UgdG9nZXRoZXIgdG8gYmVjb21lIG9uZT8=

[f]IE5vLiBOdW1iZXIgNCBpcyBhbiBlZ2cgY2VsbC4gQSB6eWdvdGUgaXMgYSBmZXJ0aWxpemVkIGVnZywgYW5kIGl0IGNvbWVzIGFib3V0IHdoZW4gYSBzcGVybSBjZWxsIGZlcnRpbGl6ZXMgYW4gZWdnLiBXaGVyZSBpbiB0aGUgZGlhZ3JhbSBkbyB5b3Ugc2VlIHRoZSBjZWxsIHRoYXQgZm9ybXMgd2hlbiB0d28gY2VsbHMgZnVzZSB0b2dldGhlciB0byBiZWNvbWUgb25lPw==

[f]IFllcy4gTnVtYmVyIDUgaXMgdGhlIHp5Z290ZSwgd2hpY2ggZm9ybXMgd2hlbiBhIHNwZXJtIGNlbGwgZmVydGlsaXplcyBhbiBlZ2cuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, would the adult man and woman shown in the bottom of the diagram be diploid or haploid?

[c]IGRpcG xvaWQ=

[c]IGhhcGxvaWQ=

[f]IFllcy4gQWR1bHRzIG9mIGFueSBhbmltYWwgc3BlY2llcyBoYXZlIGJvZGllcyB0aGF0IGFyZSBjb21wb3NlZCBvZiBkaXBsb2lkIHRpc3N1ZSwgd2l0aCB0d28gc2V0cyBvZiBjaHJvbW9zb21lcy4gVGhpcyB0aXNzdWUgZGV2ZWxvcGVkIGZyb20gYSB6eWdvdGUsIGEgZGlwbG9pZCBjZWxsIHRoYXQgY2FtZSBhYm91dCBmcm9tIHRoZSBmZXJ0aWxpemF0aW9uIG9mIGFuIGVnZyBmcm9tIGEgc3Blcm0u

[f]IE5vLiBBZHVsdHMgb2YgYW55IGFuaW1hbCBzcGVjaWVzIGhhdmUgYm9kaWVzIHRoYXQgYXJlIGNvbXBvc2VkIG9mIGRpcGxvaWQgdGlzc3VlLCB3aXRoIHR3byBzZXRzIG9mIGNocm9tb3NvbWVzLiBUaGlzIHRpc3N1ZSBkZXZlbG9wZWQgZnJvbSBhIHp5Z290ZSwgYSBkaXBsb2lkIGNlbGwgdGhhdCBjYW1lIGFib3V0IGZyb20gdGhlIGZlcnRpbGl6YXRpb24gb2YgYW4gZWdnIGZyb20gYSBzcGVybS4gVGhlIG9ubHkgY2VsbHMgaW4gYW4gYWR1bHQgbWFsZSBvciBmZW1hbGUgdGhhdCBhcmUgaGFwbG9pZCBhcmUgdGhlaXIgZ2FtZXRlcyAoc3Blcm0gb3IgZWdnIGNlbGxzLCBkZXBlbmRpbmcgb24gdGhlIHNleCkuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which structure is an ovary?

[c]ID E=

[c]IDI=

[c]IDM=

[c]IDQ=

[c]IDU=

[f]IFllcy4gTnVtYmVyIDEgaXMgdGhlIG92YXJ5Lg==

[f]IE5vLiBOdW1iZXIgMiBpcyBhIHRlc3RpcyAoc2luZ3VsYXIgZm9yIHRlc3RlcykuIExvb2sgZm9yIHRpc3N1ZSBpbiBhbiBhZHVsdCB0aGF0IHdvdWxkIGdpdmUgcmlzZSB0byBhbiBlZ2csIHdoaWNoIHlvdSBjYW4gc2VlIGF0IG51bWJlciA0Lg==

[f]IE5vLiBOdW1iZXIgMyBpcyBhIHNwZXJtIGNlbGwuPHNwYW4gY2xhc3M9IkFwcGxlLWNvbnZlcnRlZC1zcGFjZSI+wqAgPC9zcGFuPkxvb2sgZm9yIHRpc3N1ZSBpbiBhbiBhZHVsdCB0aGF0IHdvdWxkIGdpdmUgcmlzZSB0byBhbiBlZ2csIHdoaWNoIHlvdSBjYW4gc2VlIGF0IG51bWJlciA0Lg==

[f]IE5vLiBOdW1iZXIgNCBpcyBhbiBlZ2cgY2VsbC48c3BhbiBjbGFzcz0iQXBwbGUtY29udmVydGVkLXNwYWNlIj7CoCA8L3NwYW4+TG9vayBmb3IgdGlzc3VlIGluIGFuIGFkdWx0IHRoYXQgd291bGQgZ2l2ZSByaXNlIHRvIHRoaXMgZWdnLg==

[f]IE5vLiBOdW1iZXIgNSBpcyB0aGUgenlnb3RlLCB3aGljaCBmb3JtcyB3aGVuIGEgc3Blcm0gY2VsbCBmZXJ0aWxpemVzIGFuIGVnZy4gVG8gaWRlbnRpZnkgdGhlIG92YXJ5LCBsb29rIGZvciB0aXNzdWUgaW4gYW4gYWR1bHQgdGhhdCB3b3VsZCBnaXZlIHJpc2UgdG8gYW4gdW5mZXJ0aWxpemVkIGVnZywgd2hpY2ggeW91IGNhbiBzZWUgYXQgbnVtYmVyIDQuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which numbers refer to gametes?

[c]IDEgYW5kIDI=

[c]IDMgYW 5kIDQ=

[c]IDU=

[f]IE5vLiBOdW1iZXJzIDEgYW5kIDIgYXJlIHNob3dpbmcgdGhlIG92YXJ5ICgxKSBhbmQgdGhlIHRlc3RlcyAoYXQgMikuIEdhbWV0ZXMgYXJlIHNleCBjZWxscywgd2hpY2ggYXJlIHByb2R1Y2VkIGJ5IG92YXJpZXMgYW5kIHRlc3Rlcy4gV2hpY2ggbnVtYmVycyByZWZlciB0byBzZXggY2VsbHM/

[f]IFllcy4gTnVtYmVyIDMgaXMgYSBzcGVybSBjZWxsLCBhbmQgbnVtYmVyIDQgaXMgYW4gZWdnLiBFZ2cgY2VsbHMgYW5kIHNwZXJtIGNlbGxzIGFyZSBzZXggY2VsbHMsIG9yIGdhbWV0ZXMu

[f]IE5vLiBOdW1iZXIgNSBpcyBhIHp5Z290ZSwgd2hpY2ggZm9ybXMgd2hlbiBhIHNwZXJtIGNlbGwgZmVydGlsaXplcyBhbiBlZ2cuIEdhbWV0ZXMgYXJlIHNleCBjZWxscywgd2hpY2ggZnVzZSB0b2dldGhlciB0byBmb3JtIGEgenlnb3RlLiBXaGljaCBudW1iZXJzIHJlZmVyIHRvIGNlbGxzIHRoYXQgaGF2ZSBmdXNlZCB0b2dldGhlciB0byBmb3JtIGEgenlnb3RlPzwvcD4KPHAgY2xhc3M9InAxIj4=

[q] In the diagram below, which numbers refer to organs where meiosis would occur?

[c]IDEgYW 5kIDI=

[c]IDMgYW5kIDQ=

[c]IDU=

[f]IFllcy4gTnVtYmVycyAxIGFuZCAyIGFyZSBzaG93aW5nIHRoZSBvdmFyeSAoMSkgYW5kIHRoZSB0ZXN0ZXMgKDIpLiBXaXRoaW4gdGhlc2Ugb3JnYW5zLCBtZWlvc2lzIG9jY3VycywgcHJvZHVjaW5nIHNleCBjZWxscy4=

[f]IE5vLiBOdW1iZXIgMyBpcyBhIHNwZXJtIGNlbGwsIGFuZCBudW1iZXIgNCBpcyBhbiBlZ2cuIEVnZyBjZWxscyBhbmQgc3Blcm0gY2VsbHMgYXJlIHNleCBjZWxscywgb3IgZ2FtZXRlcy4gVGhleSBhcmUgcHJvZHVjZWQgYnkgbWVpb3NpcywgYnV0IG1laW9zaXMgZG9lc27igJl0IG9jY3VyIHdpdGhpbiB0aGVzZSBjZWxscy4gTW92ZSBiYWNrd2FyZHMgaW4gdGhlIGRpYWdyYW0gdG8gZmluZCB0aGUgdGlzc3VlcyB0aGF0IHByb2R1Y2VkIHRoZXNlIGdhbWV0ZXMsIGFuZCB5b3XigJlsbCBoYXZlIGZvdW5kIHRoZSBsb2NhdGlvbiBvZiBtZWlvc2lzLg==

[f]IE5vLiBOdW1iZXIgNSBpcyBhIHp5Z290ZSwgd2hpY2ggZm9ybXMgd2hlbiBhIHNwZXJtIGNlbGwgZmVydGlsaXplcyBhbiBlZ2cuIFRvIGZpbmQgd2hlcmUgbWVpb3NpcyBvY2N1cnMsIGZpbmQgdGhlIG9yZ2FucyB0aGF0IHByb2R1Y2VkIHRoZSBzcGVybSBhbmQgZWdnIHRoYXQgZnVzZWQgdG8gZm9ybSB0aGUgenlnb3RlLjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] Based on the diagram below (and any other knowledge you may have), which of the following statements is true?

[c]IEJlY2F1c2UgdGhlIGVnZyBpcyBzbyBtdWNoIGxhcmdlciB0aGVuIHRoZSBzcGVybSwgbW9yZSBnZW5ldGljIGluZm9ybWF0aW9uIGlzIGNvbnRyaWJ1dGVkIGJ5IHRoZSBtb3RoZXIgdGhhbiBieSB0aGUgZmF0aGVyLg==

[c]IFRoZSBzcGVybSBwcm92aWRlcyBtb3N0IG9mIHRoZSBnZW5ldGljIGluZm9ybWF0aW9uLiBUaGUgZWdnIHByb3ZpZGVzIHRoZSBjeXRvcGxhc20gdGhhdCBub3VyaXNoZXMgdGhlIHp5Z290ZS4=

[c]IFRoZSBlZ2csIHdpdGggaXRzIGxhcmdlciBudWNsZXVzLCBwcm92aWRlcyBtb3N0IG9mIHRoZSBnZW5ldGljIGluZm9ybWF0aW9uLiBUaGUgc3Blcm0gbWVyZWx5IHNlcnZlcyB0byBhY3RpdmF0ZSB0aGUgenlnb3RlLCBhbmQgdG8gaW5kdWNlIGl0IHRvIGRldmVsb3AgaW50byBhbiBlbWJyeW8u

[c]IEJvdGggcGFyZW50cywgdGhyb3VnaCB0aGVpciBzcGVybSBhbmQgZWdnIGNlbGxzLCBjb250cmlidXRl IDEvMiBvZiB0aGUgZ2VuZXRpYyBpbmZvcm1hdGlvbiByZWNlaXZlZCBieSB0aGUgb2Zmc3ByaW5nLg==

[f]IE5vLiBEZXNwaXRlIHRoZWlyIGRpZmZlcmVudCBzaXplcywgYm90aCB0aGUgZWdnIGFuZCBzcGVybSBoYXZlIGVxdWFsIGFtb3VudHMgb2YgZ2VuZXRpYyBpbmZvcm1hdGlvbi4gTmV4dCB0aW1lLCBjaG9zZSBhIGRpZmZlcmVudCBhbnN3ZXIu

[f]IE5vLiBXaGlsZSB0aGUgZWdnIGRvZXMgY29udHJpYnV0ZSBtdWNoIG1vcmUgY3l0b3BsYXNtLCBib3RoIHRoZSBlZ2cgYW5kIHNwZXJtIGhhdmUgZXF1YWwgYW1vdW50cyBvZiBnZW5ldGljIGluZm9ybWF0aW9uLiBOZXh0IHRpbWUsIGNob3NlIGEgZGlmZmVyZW50IGFuc3dlci4=

[f]IE5vLiBEZXNwaXRlIHRoZSBmYWN0IHRoYXQgdGhpcyBkaWFncmFtIHNob3dzIGEgbXVjaCBsYXJnZXI8c3BhbiBjbGFzcz0iQXBwbGUtY29udmVydGVkLXNwYWNlIj7CoCA8L3NwYW4+bnVjbGV1cyBpbiB0aGUgZWdnLCB0aGUgZWdnLCBpbiBmYWN0LDxzcGFuIGNsYXNzPSJBcHBsZS1jb252ZXJ0ZWQtc3BhY2UiPsKgIDwvc3Bhbj5oYXMgbm8gbW9yZSBnZW5ldGljIGluZm9ybWF0aW9uIHRoYW4gdGhlIHNwZXJtLiBOZXh0IHRpbWUsIGNob3NlIGEgZGlmZmVyZW50IGFuc3dlci4=

[f]IENvcnJlY3QuIEhhbGYgb2YgdGhlIGdlbmV0aWMgaW5mb3JtYXRpb24gaXMgY29udHJpYnV0ZWQgYnkgdGhlIG1vdGhlciwgYW5kIGhhbGYgaXMgY29udHJpYnV0ZWQgYnkgdGhlIGZhdGhlci48L3A+CjxwIGNsYXNzPSJwMSI+PHN0cm9uZz48L3N0cm9uZz4=

[q] Based on the diagram below (and any other knowledge you may have), which of the following statements about fertilization is true?

[c]IER1cmluZyBmZXJ0aWxpemF0aW9uLCB0d28gZGlwbG9pZCB6eWdvdGVzIGZ1c2UgdG8gZm9ybSBoYXBsb2lkIGdhbWV0ZXMu

[c]IER1cmluZyBmZXJ0aWxpemF0aW9uLCB0d28gZGlwbG9pZCBnYW1ldGVzIGZ1c2UgdG8gZm9ybSBhIGhhcGxvaWQgenlnb3RlLg==

[c]IEZlcnRpbGl6YXRpb24gY3JlYXRlcyBhIGRpcGxvaWQgenlnb3 RlIGZyb20gZnVzaW9uIG9mIHR3byBoYXBsb2lkIGdhbWV0ZXMu

[f]IE5vLiBMb29rIGF0IHRoZSBkaXJlY3Rpb24gb2YgdGhlIGFycm93cyBpbiB0aGUgZGlhZ3JhbS4gVGhlIHNwZXJtIGFuZCBlZ2cgY2VsbCBtb3ZlIGZvcndhcmQgaW4gdGltZSB0byBiZWNvbWUgYSB6eWdvdGUuIEluIGFkZGl0aW9uLCByZW1lbWJlciB0aGF0IGVhY2ggZ2FtZXRlIGhhcyBvbmx5IG9uZSBjaHJvbW9zb21lIHNldCAobWFraW5nIGl0IGhhcGxvaWQpLCB3aGlsZSB0aGUgenlnb3RlIGhhcyB0d28u

[f]IE5vLiBXaGlsZSB5b3UgaGF2ZSB0aGUgb3ZlcmFsbCBzZXF1ZW5jZSBjb3JyZWN0IChnYW1ldGVzIGZ1c2UgdG8gZm9ybSBhIHp5Z290ZSksIHlvdSBuZWVkIHRvIGNsYXJpZnkgdGhlIGNocm9tb3NvbWFsIGNvbmRpdGlvbiBvZiB0aGUgZ2FtZXRlcyBhbmQgdGhlIHp5Z290ZS4gUmVtZW1iZXJpbmcgdGhhdCB0aGUg4oCYZGnigJkgaW4g4oCYZGlwbG9pZOKAmSBtZWFucyDigJh0d2/igJkgbWlnaHQgaGVscCB5b3UgdGhlIG5leHQgdGltZSB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24u

[f]IFllcy4gVGhhdOKAmXMgZXhhY3RseSB3aGF0IGhhcHBlbnMgaW4gZmVydGlsaXphdGlvbiwgd2hlbiB0d28gaGFwbG9pZCBnYW1ldGVzIGZ1c2UgdG8gZm9ybSBhIGRpcGxvaWQgenlnb3RlLg==

[x]
[restart]

[/qwiz]

4. Meiosis Involves Two Cell Divisions

Chromosome duplication occurs during mitosis and meiosis

As described above, meiosis takes diploid germ cells in the ovaries or testes and transforms them into haploid gametes. But there’s a fact about meiosis that can be confusing. Meiosis evolved from (or with) mitosis. As a result, meiosis (like mitosis) begins with an interphase during which chromosomes are replicated, becoming two connected sister chromatids. Because of this, meiosis involves two cell divisions. After replication (“1” below), there’s meiosis 1 (which is shown as “2” in the diagram below), followed by meiosis 2 (“3” below)

Focusing solely on homologous pairs and sister chromatids, here’s what happens during each division:

  • Meiosis 1 (“2” below): homologous pairs are separated. Diploid cells become haploid.
  • Meiosis 2 (“3” below): sister chromatids are pulled apart, creating four haploid gametes.

Got it? Take this quiz to help consolidate your understanding of the difference between meiosis 1 and 2.

5. Quiz: Meiosis 1 v. Meiosis 2

[qwiz qrecord_id=”sciencemusicvideosMeister1961-Meiosis: meiosis 1 v meiosis 2″]

[h]Quiz: Meiosis 1 v. Meiosis 2

[i]

[q] In the diagram below, which number shows separation of homologous pairs.

[c]IDE=

[c]ID I=

[c]IDM=

[f]IE5vLiBOb3RpY2UgaG93IHRoZSBob21vbG9nb3VzIHBhaXJzICh0aGUgY2hyb21vc29tZXMgdGhhdCBhcmUgc2hvd24gYXMgYmVpbmcgbWF0Y2hlZCBieSBzaXplIGJ1dCBub3QgY29sb3IpLCBhcmUgc3RpbGwgdG9nZXRoZXIgaW5zaWRlIHRoZSBzYW1lIG51Y2xldXMgYWZ0ZXIgc3RlcCBvbmUuIEZpbmQgYSBzdGVwIHdoZXJlIHRoZXNlIGhvbW9sb2dvdXMgY2hyb21vc29tZXMgaGF2ZSBiZWVuIHNlcGFyYXRlZCBpbnRvIGRpZmZlcmVudCBudWNsZWku

[f]IEV4YWN0bHkuIFN0ZXAgMiBzaG93cyBob21vbG9nb3VzIHBhaXJzIGJlaW5nIHNlcGFyYXRlZCBpbnRvIGRpZmZlcmVudCBkYXVnaHRlciBjZWxscy4=

[f]IE5vLiBJbiBzdGVwIHRocmVlLCB0aGUgaG9tb2xvZ291cyBwYWlycyBoYXZlIGFscmVhZHkgYmVlbiBzZXBhcmF0ZWQuIFRocmVlIHNob3dzIHNpc3RlciBjaHJvbWF0aWRzIGJlaW5nIHB1bGxlZCBhcGFydC4gTmV4dCB0aW1lLCBjaG9vc2UgYW4gZWFybGllciBzdGVwIGluIHRoZSBwcm9jZXNzLjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] In the diagram below, which number shows separation of sister chromatids?

[c]IDE=

[c]IDI=

[c]ID M=

[f]IE5vLiBJbiB0aGlzIGZpcnN0IHN0ZXAsIHlvdSBjYW4gc2VlIHNpbmdsZSBjaHJvbW9zb21lcyBiZWNvbWluZyBkb3VibGVkIGNocm9tb3NvbWVzLCB3aGljaCBhcmUgY29tcG9zZWQgb2Ygc2lzdGVyIGNocm9tYXRpZHMuIE5leHQgdGltZSwgdHJ5IHRvIGlkZW50aWZ5IGEgc3RlcCB3aGVyZSB0aGVzZSBzaXN0ZXIgY2hyb21hdGlkcyBhcmUgcHVsbGVkIGFwYXJ0Lg==

[f]IE5vLiBTdGVwIDIgc2hvd3MgaG9tb2xvZ291cyBwYWlycyBiZWluZyBzZXBhcmF0ZWQgaW50byBkaWZmZXJlbnQgZGF1Z2h0ZXIgY2VsbHMu

[f]IENvcnJlY3QuIEluIHN0ZXAgdGhyZWUsIHNpc3RlciBjaHJvbWF0aWRzIGFyZSBiZWluZyBwdWxsZWQgYXBhcnQuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which number shows duplication of chromosomes?

[c]ID E=

[c]IDI=

[c]IDM=

[f]IFllcy4gSW4gdGhpcyBmaXJzdCBzdGVwLCB5b3UgY2FuIHNlZSBzaW5nbGUgY2hyb21vc29tZXMgYmVjb21pbmcgZG91YmxlZCBjaHJvbW9zb21lcywgZWFjaCBvZiB3aGljaCBpcyBjb21wb3NlZCBvZiBzaXN0ZXIgY2hyb21hdGlkcy4=

[f]IE5vLiBTdGVwIDIgc2hvd3MgaG9tb2xvZ291cyBwYWlycyBiZWluZyBzZXBhcmF0ZWQgaW50byBkaWZmZXJlbnQgZGF1Z2h0ZXIgY2VsbHMuIEZpbmQgYSBzdGVwIHdoZXJlIHNpbmdsZSBjaHJvbW9zb21lcywgd2hpY2ggbG9vayBsaWtlIHRoaWNrIGxpbmVzLCBiZWNvbWUgZG91YmxlZCBjaHJvbW9zb21lcyAod2hpY2ggbG9vayBzb21ld2hhdCBsaWtlIGFuIOKAmFjigJkpLg==

[f]IE5vLiBJbiBzdGVwIHRocmVlLCBzaXN0ZXIgY2hyb21hdGlkcyBhcmUgYmVpbmcgcHVsbGVkIGFwYXJ0LiBXaGF0IHlvdeKAmXJlIGxvb2tpbmcgZm9yIGlzIGFjdHVhbGx5IHRoZSBvcHBvc2l0ZS4gRmluZCBhIHN0ZXAgd2hlcmUgc2luZ2xlIGNocm9tb3NvbWVzLCB3aGljaCBsb29rIGxpa2UgdGhpY2sgbGluZXMsIGJlY29tZSBkb3VibGVkIGNocm9tb3NvbWVzICh3aGljaCBsb29rIHNvbWV3aGF0IGxpa2UgYW4g4oCYWOKAmSkuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] In the diagram below, which number shows where the cell changes from diploid to haploid?

[c]IDE=

[c]ID I=

[c]IDM=

[f]IE5vLiBJbiB0aGlzIGZpcnN0IHN0ZXAsIHlvdSBjYW4gc2VlIHNpbmdsZSBjaHJvbW9zb21lcyBiZWNvbWluZyBkb3VibGVkIGNocm9tb3NvbWVzLCBlYWNoIG9mIHdoaWNoIGlzIGNvbXBvc2VkIG9mIHNpc3RlciBjaHJvbWF0aWRzLiBZb3XigJlyZSBsb29raW5nIGZvciB0aGUgc3RhZ2Ugd2hlcmUgdGhlIG1hdGNoZWQgaG9tb2xvZ291cyBwYWlycyBnZXQgc2VudCB0byBkaWZmZXJlbnQgZGF1Z2h0ZXIgY2VsbHMu

[f]IFBlcmZlY3QuIFN0ZXAgMiBzaG93cyBob21vbG9nb3VzIHBhaXJzIGJlaW5nIHNlcGFyYXRlZCBpbnRvIGRpZmZlcmVudCBkYXVnaHRlciBjZWxscy4gQXMgdGhhdCBoYXBwZW5zLCB0aGUgY2VsbCBpcyB0cmFuc2Zvcm1lZCBmcm9tIGhhdmluZyB0d28gY2hyb21vc29tZSBzZXRzIHRvIGhhdmluZyBvbmUuIEFub3RoZXIgd2F5IG9mIHNheWluZyB0aGlzIGlzIHRoYXQgdGhlIGNlbGwgaXMgY2hhbmdpbmcgZnJvbSBiZWluZyBkaXBsb2lkIHRvIGJlaW5nIGhhcGxvaWQu

[f]IE5vLiBJbiBzdGVwIHRocmVlLCBzaXN0ZXIgY2hyb21hdGlkcyBhcmUgYmVpbmcgcHVsbGVkIGFwYXJ0LiBCeSB0aGlzIHBvaW50LCB0aGUgY2VsbHMgYXJlIGFscmVhZHkgaGFwbG9pZCAoYnV0IHRoZWlyIGNocm9tb3NvbWVzIGFyZSBzdGlsbCBkb3VibGVkKS4gTmV4dCB0aW1lLCBjaG9vc2UgYW4gZWFybGllciBwaGFzZSBpbiB0aGUgcHJvY2Vzcy48L3A+CjxwIGNsYXNzPSJwMSI+

[q] In the diagram below, which number shows a process that results in haploid gametes with single chromosomes.

[c]IDE=

[c]IDI=

[c]ID M=

[f]IE5vLiBJbiB0aGlzIGZpcnN0IHN0ZXAsIHlvdSBjYW4gc2VlIHNpbmdsZSBjaHJvbW9zb21lcyBiZWNvbWluZyBkb3VibGVkIGNocm9tb3NvbWVzLCBlYWNoIG9mIHdoaWNoIGlzIGNvbXBvc2VkIG9mIHR3byBzaXN0ZXIgY2hyb21hdGlkcy4gWW914oCZcmUgbG9va2luZyBmb3IgYSBsYXRlciBzdGFnZSBpbiB0aGUgcHJvY2Vzcy4=

[f]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

[f]IE5pY2UuIEluIHN0ZXAgdGhyZWUsIHNpc3RlciBjaHJvbWF0aWRzIGFyZSBiZWluZyBwdWxsZWQgYXBhcnQsIHNvIHRoZSBkb3VibGVkIGNocm9tb3NvbWVzIGFyZSBiZWNvbWluZyBzaW5nbGUgY2hyb21vc29tZXMuIEJ5IHRoaXMgcG9pbnQsIHRoZSBjZWxscyBhcmUgYWxyZWFkeSBoYXBsb2lkLiBUaGUgcmVzdWx0LCBpbiBvdGhlciB3b3JkcywgaXMgZm91ciBoYXBsb2lkIGdhbWV0ZXMgd2l0aCBzaW5nbGUgY2hyb21vc29tZXMuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] Which process separates homologous pairs?

[c]IG1laW9z aXMgMQ==

[c]IG1laW9zaXMgMg==

[f]IFRoYXTigJlzIHJpZ2h0LiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMu

[f]IE5vLiBNZWlvc2lzIDIgc2VwYXJhdGVzIHNpc3RlciBjaHJvbWF0aWRzLjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] Which process reduces chromosome number from diploid to haploid?

[c]IG1laW9z aXMgMQ==

[c]IG1laW9zaXMgMg==

[f]IFRoYXTigJlzIHJpZ2h0LiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMuIEFzIGl0IGRvZXMsIGNocm9tb3NvbWUgbnVtYmVyIGlzIHJlZHVjZWQgZnJvbSB0d28gc2V0cyAob25lIGZyb20gdGhlIG1vdGhlciwgb25lIGZyb20gdGhlIGZhdGhlciksIHRvIG9uZSBzZXQu

[f]IE5vLiBNZWlvc2lzIDIgc2VwYXJhdGVzIHNpc3RlciBjaHJvbWF0aWRzLiBUaGUgY2VsbHMgYXJlIGFscmVhZHkgaGFwbG9pZC48L3A+CjxwIGNsYXNzPSJwMSI+

[q] Which process results in two haploid cells with doubled chromosomes?

[c]IG1laW9z aXMgMQ==

[c]IG1laW9zaXMgMg==

[f]IFRoYXTigJlzIHJpZ2h0LiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMuIEFzIGl0IGRvZXMsIGNocm9tb3NvbWUgbnVtYmVyIGdvZXMgZnJvbSBkaXBsb2lkIHRvIGhhcGxvaWQuIEVhY2ggY2hyb21vc29tZSwgaG93ZXZlciwgaXMgc3RpbGwgZG91YmxlZC4=

[f]IE5vLiBNZWlvc2lzIDIgc2VwYXJhdGVzIHNpc3RlciBjaHJvbWF0aWRzLiBUaGUgcmVzdWx0IGlzIGZvdXIgaGFwbG9pZCBkYXVnaHRlciBjZWxscywgZWFjaCBvZiB3aGljaCBoYXMgc2luZ2xlIGNocm9tb3NvbWVzLjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] Which process separates sister chromatids?

[c]IG1laW9zaXMgMQ==

[c]IG1laW9z aXMgMg==

[f]IE5vLiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMu

[f]IEdvb2Qgam9iLiBNZWlvc2lzIDIgc2VwYXJhdGVzIHNpc3RlciBjaHJvbWF0aWRzLjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] Which process results in four haploid cells with single chromosomes?

[c]IG1laW9zaXMgMQ==

[c]IG1laW9z aXMgMg==

[f]IE5vLiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMuIFRoZSByZXN1bHQgaXMgdHdvIGhhcGxvaWQgY2VsbHMgd2l0aCBkb3VibGVkIGNocm9tb3NvbWVzLg==

[f]IFRoYXTigJlzIGNvcnJlY3QuIE1laW9zaXMgMiBzZXBhcmF0ZXMgc2lzdGVyIGNocm9tYXRpZHMuIFRoZSByZXN1bHQgaXMgZm91ciBoYXBsb2lkIGRhdWdodGVyIGNlbGxzLCBlYWNoIG9mIHdoaWNoIGhhcyBzaW5nbGUgY2hyb21vc29tZXMuPC9wPgo8cCBjbGFzcz0icDEiPg==

[q] Which process reduces chromosomes from two sets to one set?

[c]IG1laW9z aXMgMQ==

[c]IG1laW9zaXMgMg==

[f]IEV4YWN0bHkuIE1laW9zaXMgMSBzZXBhcmF0ZXMgaG9tb2xvZ291cyBwYWlycy4gVGhlIHJlc3VsdCBpcyB0d28gZGF1Z2h0ZXIgY2VsbHMsIGVhY2ggd2l0aCBvbmUgc2V0IG9mIGNocm9tb3NvbWVzLiBJbiBlYWNoIHNldCwgdGhlIGNocm9tb3NvbWVzIGFyZSBzdGlsbCBkb3VibGVkLg==

[f]IE5vLiBNZWlvc2lzIDIgc2VwYXJhdGVzIHNpc3RlciBjaHJvbWF0aWRzLiBNZWlvc2lzIDEgaGFzIGFscmVhZHkgY3V0IHRoZSBudW1iZXIgb2YgY2hyb21vc29tZXMgZG93biB0byBvbmUgc2V0LjwvcD4KPHAgY2xhc3M9InAxIj4=

[q] Which process changes doubled chromosomes into single chromosomes.

[c]IG1laW9zaXMgMQ==

[c]IG1laW9z aXMgMg==

[f]IE5vLiBNZWlvc2lzIDEgc2VwYXJhdGVzIGhvbW9sb2dvdXMgcGFpcnMuIEVhY2ggcmVzdWx0aW5nIGNocm9tb3NvbWUgaXMgc3RpbGwgZG91YmxlZC4=

[f]IFllcy4gTWVpb3NpcyAyIHNlcGFyYXRlcyBzaXN0ZXIgY2hyb21hdGlkcy4gVGhpcyBjaGFuZ2VzIGRvdWJsZWQgY2hyb21vc29tZXMgKGNvbnNpc3Rpbmcgb2YgdHdvIHNpc3RlciBjaHJvbWF0aWRzKTxzcGFuIGNsYXNzPSJBcHBsZS1jb252ZXJ0ZWQtc3BhY2UiPsKgIDwvc3Bhbj5pbnRvIHNpbmdsZSBjaHJvbW9zb21lcy4=

[x]
[restart]

[/qwiz]

6. Comparing Mitosis and Meiosis

At this point, it makes sense to review the differences between mitosis and meiosis. To do so, try the quiz below.

[qwiz qrecord_id=”sciencemusicvideosMeister1961-Meiosis: meiosis v. mitosis”]

[h]Meiosis Quiz 2: Meiosis v. Mitosis

[i]

[q] The kind of cell division associated with sexual reproduction:
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IENvcnJlY3QuIFNleHVhbCByZXByb2R1Y3Rpb24gcmVxdWlyZXMgcHJvZHVjdGlvbiBvZiBoYXBsb2lkIGdhbWV0ZXMsIGFuZCB0aGVzZSBhcmUgcHJvZHVjZWQgdGhyb3VnaCBtZWlvc2lzLg==
[f]IE5vLiBNaXRvc2lzIGlzIGFzc29jaWF0ZWQgd2l0aCBhc2V4dWFsIHJlcHJvZHVjdGlvbiAoaW4gdW5pY2VsbHVsYXIgZXVrYXJ5b3RlcykuIEluIG11bHRpY2VsbHVsYXIgb3JnYW5pc21zIGxpa2UgaHVtYW5zLCBtaXRvc2lzIGlzIGhvdyB3ZSBncm93IGFuZCBkZXZlbG9wLg==

[q] Somatic cells reproduce themselves through
[c]IG1laW9zaXM=
[c]IG1pdG 9zaXM=
[f]IE5vLiBNZWlvc2lzIGlzIGhvdyBzZXggY2VsbHMgKGVnZyBhbmQgc3Blcm0gY2VsbHMpIGFyZSBwcm9kdWNlZC4=
[f]IFllcy4gTWl0b3NpcyBpcyBob3cgdGhlIHNvbWF0aWMgY2VsbHMgdGhhdCBtYWtlIHVwIG91ciBib2R5IHRpc3N1ZXMgcmVwcm9kdWNlIHRoZW1zZWx2ZXMuIFlvdSBncmV3IGZyb20gYSBzaW5nbGUgY2VsbGVkIHp5Z290ZSBpbnRvIHRoZSB0cmlsbGlvbnMgb2YgY2VsbHMgdGhhdCBtYWtlIHlvdSB1cCB0b2RheSB0aHJvdWdoIG1pdG9zaXMu

[q] Gametes are created through
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IFllcy4gTWVpb3NpcyBpcyBob3cgZ2FtZXRlcyAoZWdnIGFuZCBzcGVybSBjZWxscykgYXJlIHByb2R1Y2VkLg==
[f]IE5vLiBNaXRvc2lzIGlzIGhvdyB0aGUgc29tYXRpYyBjZWxscyB0aGF0IG1ha2UgdXAgb3VyIGJvZHkgdGlzc3VlcyBhcmUgcHJvZHVjZWQu

[q] Genetic variation arises through
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IFllcy4gTWVpb3NpcyBjcmVhdGVzIHZhcmlhdGlvbi4gTWVpb3NpcyBpbnZvbHZlcyB0d28gcHJvY2Vzc2VzLCBjcm9zc2luZyBvdmVyIGFuZCBpbmRlcGVuZGVudCBhc3NvcnRtZW50LCB0aGF0IG1peCB1cCBnZW5lcyBpbiBhIHdheSB0aGF0IGNyZWF0ZXMgYnJhbmQgbmV3IGNvbWJpbmF0aW9ucyBvZiBnZW5lcy4=
[f]IE5vLiBNaXRvc2lzIGNyZWF0ZXMgYW4gZXhhY3QgZHVwbGljYXRlIG9mIHRoZSBwYXJlbnQgY2VsbC4gVGhlIGRhdWdodGVyIGNlbGxzIHdoaWNoIHJlc3VsdCBmcm9tIG1pdG9zaXMgYXJlIGdlbmV0aWMgY2xvbmVzIG9mIHRoZSBwYXJlbnQgY2VsbC4gTm8gbmV3IGdlbmV0aWMgdmFyaWF0aW9uIGlzIHByb2R1Y2VkLg==

[q] Which type of cell division cuts chromosome number in half?
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IFllcy4gTWVpb3NpcyByZWR1Y2VzIGNocm9tb3NvbWUgbnVtYmVyIGZyb20gdHdvIHNldHMgdG8gb25lIHNldCAoZnJvbSBkaXBsb2lkIHRvIGhhcGxvaWQpLg==
[f]IE5vLiBNaXRvc2lzIGtlZXBzIHRoZSBjaHJvbW9zb21lIG51bWJlciBleGFjdGx5IHRoZSBzYW1lLg==

[q] Which type of cell division creates two daughter cells that are genetic clones of the parent cell?
[c]IG1laW9zaXM=
[c]IG1pdG 9zaXM=
[f]IE5vLiBNZWlvc2lzIGNyZWF0ZXMgZm91ciBkYXVnaHRlciBjZWxscyB0aGF0IGFyZSBnZW5ldGljYWxseSBkaXN0aW5jdCBmcm9tIHRoZSBwYXJlbnQgY2VsbC4=
[f]IFllcy4gTWl0b3NpcyByZXN1bHRzIGluIHR3byBkYXVnaHRlciBjZWxscyB0aGF0IGFyZSBleGFjdCBnZW5ldGljIGNsb25lcyBvZiB0aGUgcGFyZW50IGNlbGwu

[q] Animals grow from single celled zygotes into multicellular organisms through
[c]IG1laW9zaXM=
[c]IG1pdG 9zaXM=
[f]IE5vLiBNZWlvc2lzIGlzIGhvdyBtdWx0aWNlbGx1bGFyIG9yZ2FuaXNtcyBtYWtlIGdhbWV0ZXMgZm9yIHJlcHJvZHVjdGlvbi4=
[f]IFllcy4gTWl0b3NpcyBpcyBob3cgYW5pbWFscyBncm93IGZyb20gYSBzaW5nbGUtY2VsbGVkIHp5Z290ZXMgaW50byBtdWx0aWNlbGx1bGFyIGFkdWx0cy4=

[q] Animals create sperm and egg cells created through
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IFllcy4gTWVpb3NpcyBpcyBob3cgZ2FtZXRlcyAoZWdnIGFuZCBzcGVybSBjZWxscykgYXJlIHByb2R1Y2VkLg==
[f]IE5vLiBNaXRvc2lzIGlzIGhvdyB0aGUgc29tYXRpYyBjZWxscyB0aGF0IG1ha2UgdXAgb3VyIGJvZHkgdGlzc3VlcyBhcmUgY3JlYXRlZC4=

[q] Which type of cell division involves only one round of cell division?
[c]IG1laW9zaXM=
[c]IG1pdG 9zaXM=
[f]IE5vLiBEdXJpbmcgbWVpb3NpcywgY2VsbHMgZGl2aWRlIHR3aWNlIGFzIHRoZXkgcmVkdWNlIGNocm9tb3NvbWUgbnVtYmVyIGZyb20gZGlwbG9pZCB0byBoYXBsb2lkLCBhbmQgdGhlbiBkaXZpZGUgZG91YmxlZCBjaHJvbW9zb21lcyBpbnRvIHNpbmdsZSBjaHJvbW9zb21lcy4=
[f]IFllcy4gTWl0b3NpcyBpbnZvbHZlcyBvbmx5IG9uZSByb3VuZCBvZiBjZWxsIGRpdmlzaW9uIGFzIGRvdWJsZWQgY2hyb21vc29tZXMgYXJlIHNwbGl0IGludG8gc2luZ2xlIGNocm9tb3NvbWVzLCBhbmQgdGhlIGNlbGwgc3BsaXRzIGluIGhhbGYu

[q] Which type of cell division involves two rounds of cell division?
[c]IG1laW 9zaXM=
[c]IG1pdG9zaXM=
[f]IFllcy4gRHVyaW5nIG1laW9zaXMsIGNlbGxzIGRpdmlkZSB0d2ljZSBhcyB0aGV5IHJlZHVjZSBjaHJvbW9zb21lIG51bWJlciBmcm9tIGRpcGxvaWQgdG8gaGFwbG9pZCwgYW5kIHRoZW4gZGl2aWRlIGRvdWJsZWQgY2hyb21vc29tZXMgaW50byBzaW5nbGUgY2hyb21vc29tZXMu
[f]IE5vLiBNaXRvc2lzIGludm9sdmVzIG9ubHkgb25lIHJvdW5kIG9mIGNlbGwgZGl2aXNpb24gYXMgZG91YmxlZCBjaHJvbW9zb21lcyBhcmUgc3BsaXQgaW50byBzaW5nbGUgY2hyb21vc29tZXMsIGFuZCB0aGUgY2VsbCBzcGxpdHMgaW4gaGFsZi4=

[q] Which of the numbered diagrams below represents meiosis?

[c]IDE=
[c]ID I=
[f]IE5vLiBJbiBkaWFncmFtIDEsIHlvdSBzZWUgb25seSBvbmUgcm91bmQgb2YgY2VsbCBkaXZpc2lvbi4gRHVyaW5nIG1laW9zaXMsIGNlbGxzIGRpdmlkZSB0d2ljZSBhcyB0aGV5IHJlZHVjZSBjaHJvbW9zb21lIG51bWJlciBmcm9tIGRpcGxvaWQgdG8gaGFwbG9pZCwgYW5kIHRoZW4gZGl2aWRlIGRvdWJsZWQgY2hyb21vc29tZXMgaW50byBzaW5nbGUgY2hyb21zb21lcy4=
[f]IEV4Y2VsbGVudC4gRGlhZ3JhbSAyIHJlcHJlc2VudHMgbWVpb3Npcywgd2hpY2ggeW91IGNhbiBzZWUgaXMgaGFwcGVuaW5nIGJlY2F1c2Ugb2YgdGhlIHR3byByb3VuZHMgb2YgY2VsbCBkaXZpc2lvbiB0aGF0IGFyZSBvY2N1cnJpbmcsIGFuZCBiZWNhdXNlIHRoZSBjaHJvbW9zb21lIG51bWJlciBpcyBiZWluZyByZWR1Y2VkIGluIGhhbGYgKGZvdXIgaW4gdGhlIHBhcmVudCBjZWxsLCB0d28gaW4gdGhlIGRhdWdodGVyIGNlbGxzKS4=

[q] Which of the numbered diagrams below represents mitosis?

[c]ID E=
[c]IDI=
[f]IFllcy4gSW4gZGlhZ3JhbSAxLCB5b3Ugc2VlIG9ubHkgb25lIHJvdW5kIG9mIGNlbGwgZGl2aXNpb24uIEluIGFkZGl0aW9uLCB5b3UgY2FuIHNlZSB0aGF0IHRoZSBjaHJvbW9zb21lIG51bWJlciBzdGF5cyB0aGUgc2FtZSBpbiBib3RoIHBhcmVudCBjZWxscyBhbmQgZGF1Z2h0ZXIgY2VsbHMuIEJvdGggb2YgdGhlc2UgaW5kaWNhdGUgdGhhdCB3aGF0IHlvdeKAmXJlIHNlZWluZyBpcyBtaXRvc2lzLg==
[f]IE5vLiBEaWFncmFtIDIgcmVwcmVzZW50cyBtZWlvc2lzLCB3aGljaCB5b3UgY2FuIHNlZSBpcyBoYXBwZW5pbmcgYmVjYXVzZSBvZiB0aGUgdHdvIHJvdW5kcyBvZiBjZWxsIGRpdmlzaW9uIHRoYXQgYXJlIG9jY3VycmluZywgYW5kIGJlY2F1c2UgdGhlIGNocm9tb3NvbWUgbnVtYmVyIGlzIGJlaW5nIHJlZHVjZWQgaW4gaGFsZiAoZm91ciBpbiB0aGUgcGFyZW50IGNlbGwsIHR3byBpbiB0aGUgZGF1Z2h0ZXIgY2VsbHMpLiBJbiBtaXRvc2lzLCB5b3Ugc2VlIG9ubHkgb25lIHJvdW5kIG9mIGNlbGwgZGl2aXNpb24sIGFuZCB0aGUgY2hyb21vc29tZSBudW1iZXIgc3RheXMgdGhlIHNhbWUu

[q] Which of the following statements about mitosis and meiosis is true?
[c]IE1pdG9zaXMgYW5kIG1laW9zaXMgYXJlIHVuaXZlcnNhbCBwcm9jZXNzZXMgdGhhdCBvY2N1ciBpbiBib3RoIHByb2thcnlvdGVzIGFuZCBldWthcnlvdGVzLg==
[c]IE1pdG9zaXMgb2NjdXJzIGluIHByb2thcnlvdGVzLiBNZWlvc2lzIG9jY3VycyBpbiBldWthcnlvdGVzLg==
[c]IE1pdG9zaXMgYW5kIG1laW9zaXMgb2NjdXIgaW4gcHJva2FyeW90ZXMgb25seS4=
[c]IE1pdG9zaXMgYW5kIG1laW9zaXMgb2Nj dXIgaW4gZXVrYXJ5b3RlcyBvbmx5Lg==
[f]IE5vLiBNaXRvc2lzIGFuZCBtZWlvc2lzIG5ldmVyIG9jY3VyIGluIHByb2thcnlvdGVzLiBOZXh0IHRpbWUsIGNob29zZSBhbm90aGVyIGFuc3dlci4=
[f]IE5vLiBNaXRvc2lzIGFuZCBtZWlvc2lzIG5ldmVyIG9jY3VyIGluIHByb2thcnlvdGVzLiBOZXh0IHRpbWUsIGNob29zZSBhbm90aGVyIGFuc3dlci4=
[f]IE5vLiBNaXRvc2lzIGFuZCBtZWlvc2lzIG5ldmVyIG9jY3VyIGluIHByb2thcnlvdGVzLiBOZXh0IHRpbWUsIGNob29zZSBhbm90aGVyIGFuc3dlci4=
[f]IEV4YWN0bHkuIEJvdGggbWl0b3NpcyBhbmQgbWVpb3NpcyBhcmUgY2VsbCBkaXZpc2lvbiBwcm9jZXNzZXMgdGhhdCBhcmUgdW5pcXVlIHRvIGV1a2FyeW90ZXMu
[x]
[restart]

[/qwiz]

What Now?

Now that we’ve got the basics of meiosis covered, we can go onto the next (and most important) topic: How meiosis creates variation.

  1. Click to go on to tutorial 3 (how meiosis creates variation)
  2. Click here to go to the meiosis main menu