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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is a gamete? |
Sperm or egg which contains half the normal number of chromosomes |
Half |
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Haploid |
A cell containing half the normal number of chromosomes found in an adult cell |
Half |
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Diploid |
A cell containing the normal number of chromosomes found in an adult cell |
Normal |
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Karyotype |
The number and appearance of chromosomes present in a eukaryotic cell |
Present |
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Karyogram |
A visual image of chromosomes present on a eukaryotic cell, organised according to structure |
Image |
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Purpose of meiosis |
To produce gametes which show genetic variation |
Variation |
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Homologous chromosomes |
A pair of chromosomes, one maternal and one paternal, each with the same genes at the same loci |
Loci |
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3 sources of genetic variation |
Crossing over, random fertilisation, independent assortment |
Crazy random idiot |
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Define synapsis |
Pairing of homologous chromosomes during Prophase 1 |
P1 |
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Bivalent |
A pair of homologous chromosomes |
Two |
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Define independent assortment |
The random orientation of homologous chromosomes or chromatids during metaphase 1 and 2 |
M1and2 |
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Possible gametes combinations |
2^n where n equals haploid number |
2 |
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Define crossing over |
The exchange of genetic material between non sister chromatids |
Vanessa and nakita arguing |
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Chaismata |
The location at which crossing over occurs |
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Disjunction |
Separation of chromosomes during anaphase 1 and 2 |
A1and2 |
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Non-disjunction |
Failure of homologous chromosomes or zoster chromatids to separate, resulting in gametes with one extra, or one missing, chromosome |
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Recombinant chromosomes |
As a result of crossing over, new allele combinations are formed on chromatids |
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Non sister chromatids |
DNA molecules from homologous chromosomes which may contain different alleles |
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Sister chromatids |
Two identical DNA molecules, held together by a single centromere |
Twins |
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How many divisions in meiosis |
2 |
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Products of meiosis |
4 genetically different gametes |
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Define gene mutation |
A change in the base sequence of a gene |
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Two types of gene mutation |
Base deletion, base substitution |
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3 examples of mutagenic agents |
Toxic chemicals, ionising radiation (x rays), high energy radiation (uv) |
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