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BIO Chapter 14
Mendel and the Gene Idea
| Term | Definition |
|---|---|
| Who is Mendel? | scientist who made genetic breakthroughs by studying peas |
| Why did Mendel use peas for his research? | rapid growth and he could manually control who mated with who |
| P generation- | true-breeding parents |
| F1 generation- | p generation hybrid offspring |
| F2 generation- | second filial generation |
| True-breeding- | over many generations of self-pollination they only produce the same variety as the parent plant |
| What was the ratio of all of Mendel’s initial experiment? | 3/4 to ¼ |
| Phenotype- | expression of a physical trait |
| Alleles- | alternate versions of genes |
| Genotype- | genetic makeup |
| Dominant allele- | determines appearance |
| Recessive allele- | has no noticeable effect on appearance |
| Segregation- | two alleles for a heritable character segregate during gamete formation and end up in different gametes. |
| Punnett square- | diagraming tool used to predict allele formation |
| Homozygous- | a pair of identical alleles |
| Heterozygous- | two different alleles for the same gene |
| Multiplication rule- | the probability of two independent events occurring in combination is equal to the product of their separate probabilities |
| Incomplete dominance- | situations in which a heterozygote for a character doesn’t show a complete dominance/recessive relationship |
| Co-dominance- | when an organism is heterozygote for a character and both alleles affect the phenotype in separate, distinguishable ways. |
| Pleiotropy- | when a single gene has many phenotypic effects (i.e. sickle cell) |
| Epistasis- | a gene at one location alters the expression of a gene at another location |
| Polygenic inheritance- | many genes influence a particular character |
| Quantitative characters- | often show polygenic inheritance patterns |
| Environmental impact on phenotype- | how environment can influence phenotype |
| Multifactorial characters- | affected by many factors i.e. genotype and environment |
| The norm of reaction: | the pattern of phenotypes produced by a given genotype under different environmental conditions |
| Narrow norm of reaction- | albinism, ABO blood type, Huntington disease |
| Broader norm of reaction | skin color, height, IQ |