Genetic crosses

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Genotype and phenotype - define
G = genetic constitution of an organism. P = Expression of the genetic constitution and its interaction with the environment.
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Haploid and diploid - define
H = cell containing half the genetic code, e.g. gametes. Known as 'n'. D = cell containing full genetic material. Known as '2n'.
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Homozygous and heterozygous - define
Homo = has identical alleles for a characteristic. Hetero = has different alleles for a characteristics.
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Gene and locus - define
G = a section of DNA with coded information for enzyme and protein production). L = the position of a gene on a chromosome.
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Inheritance of sex
Sex chromosomes are heterosomes whereas all others are autosomes. Many genes present on the X are missing on the Y - men only have one copy of many genes.
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Sex linked chromosomes
Genes located on one or the other chromosomes - all confirmed sex linked genes are on the X chromosome. Recessive allelesare more often expressed in males as they only have one X compared to women's two.
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Multiple alleles
When there are more than two alternative forms of a particular gene that occupy a gene locus. This results in many slightly different phenotypes for the same trait.
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Example of multiple alleles - blood type A
A phenotype = genotype IAIA or IAIO, antigens on RBCS are A, plasma antibodies are anti-B, can have transfusions from any group but B.
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Example of multiple alleles - blood type B
B phenotype = genotype IBIB or IBIO, antigens on RBCS are B, plasma antibodies are anti-A, can have transfusions from any group but A.
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Example of multiple alleles - blood type AB
AB phenotype = genotype IAIB, antigens on RBCS are A and B, no plasma antibodies, can have transfusions from any group.
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Example of multiple alleles - blood type O
O phenotype = genotype IOIB, no antigens on RBCS, plasma antibodies are anti-A and anti-B, can have transfusions from only O.
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Monohybrid inheritance
The inheritance of a single characteristic.
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Representation of codominant alleles
Neither is dominant so the dif. alleles are not represented by upper case and lower case letters. Instead the gene has an upper case letter and each allele has a subscript upper case letter. Homozygotes - same subscript letter. Heterozygotes don't.
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What is codominance?
If two alleles both produce a protein that can function, the heterozygote's phenotype may be different from both homozygotes. The allele is therefore codominant as both produce a functioning protein.
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Card 2

Front

Haploid and diploid - define

Back

H = cell containing half the genetic code, e.g. gametes. Known as 'n'. D = cell containing full genetic material. Known as '2n'.

Card 3

Front

Homozygous and heterozygous - define

Back

Preview of the front of card 3

Card 4

Front

Gene and locus - define

Back

Preview of the front of card 4

Card 5

Front

Inheritance of sex

Back

Preview of the front of card 5
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