Term
| What does meiosis produce? |
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Definition
| Gametes. (Egg cells and sperm cells) |
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Term
| Adult body cells (somatic) are ________, containing ____ sets of chromosomes. |
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Definition
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Term
| Gametes are ________. Containing __ set of chromosomes. |
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Definition
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Term
| What is sexual reproduction? |
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Definition
| Includes the fusion of gametes to pro due a diploid zygote. |
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Term
| What is the fusion of gametes? |
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Definition
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Term
| What state dominates in humans? |
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Definition
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Term
| _______ first undergoes meiosis to produce _________ cells. |
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Definition
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Term
| Later in the life cycle, some of these diploid cells undergo meiosis to produce ___________ gametes. |
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Definition
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Term
| How many rounds of division are there in meiosis? |
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Definition
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Term
| What is the first division in meiosis called? |
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Definition
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Term
| What does the reduction division result in? |
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Definition
| daughter cells that contain ONE homologue from each chromosome pair. |
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Term
| Does DNA replication occur between meiotic divisions? |
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Definition
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Term
| What does the 2nd meiotic division do? |
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Definition
| DOES NOT reduce the number of chromosomes. Separates the sister chromatids from from each homologue. |
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Term
| Do meiotic cells go through interphase? |
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Definition
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Term
| What are the steps of Meiosis I? |
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Definition
1.) Prophase I
2.) Metaphase I
3.) Anaphase I
4.) Telophase I |
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Term
| What happens during prophase I? |
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Definition
-Chromosomes coil tightly
-Spindle forms
-Each consisting of 2 sister chromatids |
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Term
| What is the synapsis during prophase I? |
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Definition
| When crossing OVER occurs between non sister chromatids. Remain attached @ their chiasmata which then moves to the end of the chromosome arm before metaphase 1. |
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Term
| What is the synaptonemal complex? |
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Definition
| Formation also caled tetrad or bivalents. Occurs when crossing over happens. |
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Term
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Definition
| Genetic recombination between non sister chromatids. |
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Term
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Definition
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Term
| When are the homologues separated? |
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Definition
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Term
| What happens during metaphase I? |
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Definition
| -Microtubules from opposite poles attach to each HOMOLOGUE not each sister chromatid. Then they align at the metaphase plate side-by-side. Orientation of each pair on the spindle is random. |
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Term
| What is the difference in separation of genetic material in mitosis and meiosis I? |
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Definition
Meiosis = PAIRS pulled
Mitosis = Sister chromatids separated |
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Term
| Independent assortment allows what? |
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Definition
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Term
| What happens during anaphase I? |
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Definition
-Microtubules of the spindle shorten, chiasmata break.
-Homologues are separated from each other.
-Sister chromosomes remain attached to each other at their centromere. |
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Term
| After anaphase I, how many chromosomes does each pole have? |
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Definition
| A haploid set. One member of each homologous pair. |
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Term
| What happens during telophase I? |
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Definition
-nuclear envelope forms
-each nucleus is now haploid
-sister chromatids are no longer identical because of crossing over
-Cytokinesis may or may not occur after
-Meiosis II follows |
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Term
| What does meiosis II resemble? |
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Definition
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Term
| What happens during prophase II? |
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Definition
| Nuclear envelopes dissolve and new spindle apparatus forms. |
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Term
| What happens during metaphase II? |
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Definition
| Chromosomes align on metaphase plate. |
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Term
| What happens during anaphase II? |
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Definition
| Sister chromatids are separated from each other. |
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Term
| What happens during telophase II? |
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Definition
| Nuclear envelope reforms around 4 haploid daughter chromosomes and cytokinesis follows. |
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Term
| What happens to the daughter cells in animal vs plant cells? |
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Definition
Animal - directly into gametes
Plant - divide mitotically to produce more gametes |
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Term
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Definition
| Failure of chromosomes to move to opposite poles during either meiotic division. Failure to move from metaphase plate correctly. |
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Term
| What are aneuploid gametes? |
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Definition
| Gametes with missing or extra chromosomes |
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Term
| What is the most common cause of spontaneous abortion in humans? |
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Definition
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Term
| What are the 4 characteristics of meiosis? |
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Definition
1.) Synapsis and crossing over
2.) Sister chromatids remain joined at their centromeres through meiosis I
3.) Kinetochores of sister chromatids attach to same pole during meiosis 1.
4.) DNA replication is suppressed between meiosis I and II. |
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Term
| Meiosis produces __ _______ cells that are _____ genetically identical. |
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Definition
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Term
| How do genetic differences occur in meiosis? |
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Definition
- crossing over
- random alignment of homologues during metaphase I.
- mate selection |
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Term
| Mitosis produces __ ________ _________ cells. |
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Definition
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Term
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Definition
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