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Chp. 16 Bio
Simple patterns of inheritance
Question | Answer |
---|---|
Genes | Discrete particles, DNA |
Gregor Mendel | , the father of genetics, was an Austrian monk who discovered the fundamental principles of genetics by breeding garden peas. Quantitative approach. |
True Breeding | They differ from one another by only a single trait, such as flower color or height, and that trait remains the same from one generation to the next |
self-fertilize | so the parentage of the offspring is always known |
hybrid | When two individuals of different varieties are cross-fertilized, or crossed, the offspring is called a hybrid |
P generation | Parental generation |
F1 generation | offspring of P generation |
F2 generation | offspring of F1 generation |
monohybrid cross | cross between individuals that different in only one trait. |
Alleles | Alternative forms of genes. Each indiv. has two alleles. one from each parent. |
homologous chromosomes | alleles that control a particular trait. |
sperm or egg only contains one allele due to | meiosis. principle of segregation. |
Dominant Allele | Allele that is expressed. |
Recessive Allele | Allele that is not seen but still is present. |
homozygous | Individual with two identical alleles |
Heterozygous | indiv. with two different alleles. |
Phenotype | the genes that are expressed. what you see when you look at them. Purple |
Genotype | all the genes they have. PpPp |
Punnett square | easy way to figure out the possible combinations of an offspring. |
Dihybrid corss | the parents are different in two characteristics. |
principle of independent assortment | that each pair of alleles segregates independently of the others during meiosis |
Incomplete dominance | The heterozygote has a phenotype that is intermediate between the two parents. For example, a cross between white and red flowered snapdragons produces pink offspring |
Codominance | when both dominant alleles are expressed at the same time. Blood types. |
A and B blood type | Codominant |
O blood type | recessive |
Pleiotropy | One pair of alleles may affect more than one characteristic. *a mutation can happen in a single cell but can affect multiple organs. |
Epistasis | one gene may inhibit another. * albinism. masking other genes. |
Polygenic inheritance | Many alleles may be involved in regulating a single characteristic. For example, there is continuous variation in skin color and height in humans. |
Environmental factors | may influence the expression of characteristics. mall nutrition can prevent full height. *pku |
Sex-influenced traits | some traits show a gender and dosage effect. male baldness pattern doesnt affect women |
Heterozygote advantage | some genes help you become immune to diseases. while others dont. |
pedigree analysis | unknown genes primary means of looking at inheritance patterns. |
Carriers | unaffected indiv. who still carry a gene. |
Recessive genetic disorders | (more common) albinism, galactosemia, sickle-cell anemia |
Dominant disorders | (less common) Alzheimers disease, huntington, hypercholesterolmia |
Carries testing | Adults can be tested for a variety of genetic disorders. The genes for sickle cell, cystic fibrosis, Tay-Sachs, and Huntington’s |
predictive testing | test whether to see your chances of developing a certain disease. |
Amniocentesis | is a technique used to detect genetic disorders in a fetus. A small sample of amniotic fluid containing cells from the fetus is removed from the uterus. *down syndrome. |
Chorionic villus sampling | can be done earlier in pregnancy than amniocentesis, and the results are available within hours. A sample of tissue from the placenta is removed |
Newborn screening | test for certain disorder in newborns have become routine. such as PKU |