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37 Cards in this Set
- Front
- Back
Heredity |
The transfer on genes from one generation to the next.
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Genetics |
the study of heredity |
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Character |
heritable feature |
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True-breedings |
varieties created when self-fertilization produces offspring identical to the parent. |
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hybrids |
the offspring of two different varieties |
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genetic cross |
cross fertilization |
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P generation |
true breeding parental plants |
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F1 generation |
hybrid offspring |
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F2 generation |
a cross of F1 plants |
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monohybrid cross |
a cross between two individuals differing in a single character |
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Alleles |
are alternative versions of genes that account for variations in inherited characters. |
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Homozygous genotype |
has identical alleles. |
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heterozygous genotype |
has two different alleles. |
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dominant allele |
An allele that expresses its phenotypic effect even when heterozygous with a recessive allele |
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recessive allele |
has no noticable effect on an organism's appearance. |
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phenotype is |
the appearance or expression of a trait. |
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genotype is |
the genetic makeup of a trait. The same phenotype may be determined by more than one genotype. |
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law of segregation |
A sperm or egg carries only one allele for each inherited character because allele pairs separate (segregate) from each other during the production of gametes |
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Punnett square |
shows the four possible combinations of alleles that could occur when F1 and F2 gametes combine. |
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locus |
the specific location of a gene along a chromosome. |
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dihybrid cross |
a mating of parental varieties that differ in two characters. |
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law of independent assortment. |
suggested that the inheritance of one character has no effect on the inheritance of another,suggested that the dihybrid cross is the equivalent to two monohybrid crosses, and |
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A test-cross is |
the mating between an individual of unknown genotype and a homozygous recessive individual. |
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A pedigree |
shows the inheritance of a trait in a family through multiple generations, demonstrates dominant or recessive inheritance, and can also be used to deduce genotypes of family members. |
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Wild-type traits |
are those most often seen in nature and not necessarily specified by dominant alleles. |
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heterozygotes |
carriers of the recessive allele for the disorder |
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Huntington’s disease |
a degenerative disorder of the nervous system |
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Amniocentesis |
extracts samples of amniotic fluid containing fetal cells and permits karyotyping |
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Chorionic villus sampling |
removes a sample of chorionic villus tissue from the placenta and permits similar karyotyping and biochemical tests. |
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Mendel’s pea crosses always looked like one of the two parental varieties, a situation called |
Complete dominance |
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incomplete dominance |
For some characters, the appearance of F1 hybrids falls between the phenotypes of the two parental varieties. |
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Pleiotropy occurs |
when one gene influences multiple phenotypes. |
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polygenic inheritance |
a single phenotypic character results from the additive effects of two or more genes on a single phenotypic character.Human skin color is an example of polygenic inheritance. |
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Sex-linked genes |
genes located on either sex chromosome |
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Cystic fibrosis is |
characterized by an excessive secretion of very thick mucus from the lungs and other organs |
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Mendel’s pea crosses always looked like one of the two parental varieties, a situation called complete dominance.For some characters, the appearance of F1 hybrids falls between the phenotypes of the two parental varieties. This is called incomplete dominance. |
fthissh!t |
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linked genes are |
located close together on the same chromosome and tend to be inherited together. |