Terms : Hide Images
| 1039766375 | Blending Hypothesis | traits were of parents were blended, once blended could not be "unblended" | 0 | |
| 1039766376 | preformationism | the idea that organisms develop from miniature versions of themselves | 1 | |
| 1039766377 | why are pea plants an excellent model system? | 1. several varieties available 2. easy to self and cross fertilize 3. relatively fast generation time 4. produce many offspring | 2 | |
| 1039766378 | Mendel's Discoveries | 1. alleles are alternative versions of a gene 2. a diploid organism has 2 alleles for each gene, one from each parent 3. there are two types of alleles: dominant allele can mask presence of recessive allele 4. law of segregation: a diploid organism has 2 alleles for each gene, & these 2 alleles separate during gamete formation in anaphase I of meiosis | 3 | |
| 1039766379 | What is a test cross and why is it used? | breeding an individual with unknown genotype with recessive homozygote -used to determine the genotype of an organism with a dominant phenotype | 4 | |
| 1039766380 | Law of Independent Assortment | 2 different genes assort independently during gamete formation in metaphase I of meiosis -there are exceptions to this rule | 5 | |
| 1039766381 | what is a monohybrid? | heterozygous for the one particular character being followed in the cross | 6 | |
| 1039766382 | what is a monohybrid cross? | cross used to observe one trait | 7 | |
| 1039766383 | What is a dihybrid cross? | a cross used to observe two traits | 8 | |
| 1039766384 | what is a character? | heritable feature that varies among individuals ie. flower color | 9 | |
| 1039766385 | what is a trait? | each variant for a character ie. purple, white | 10 | |
| 1039766386 | what kind of characters did Mendel choose? | characters that occurred in 2 distinct forms (no intermediate) | 11 | |
| 1039766387 | what is true breeding? | organisms that produce offspring of the same variety over many generations of self-pollination | 12 | |
| 1039766388 | what is hybridization? | crossing of 2 true breeding varieties | 13 | |
| 1039766389 | what is the F1 generation? | first filial generation, hybrid offspring of the P generation | 14 | |
| 1039766390 | what is the F2 generation? | offspring of the F1 hybrids self pollinating with other F1 hybrids | 15 | |
| 1039766391 | Results of Mendel's key experiment | both purple and white flowered plants appeared in F2 generation; ratio = 3:1 | 16 | |
| 1039766392 | Conclusion from Mendel's key experiment | -heritable factor for recessive trait was masked by the presence of the factor for the purple flower, which is the dominant trait -refuted blending model -traits are not always inherited together | 17 | |
| 1039766393 | If blending model of inheritance were correct.. | the F1 hybrids from a cross between purple and white flowers would have been pale purple flowers | 18 | |
| 1039766394 | Degrees of Dominance | complete dominance, incomplete dominance, codominance | 19 | |
| 1039766395 | what is complete dominance? | phenotype of heterozygote and dominant homozygote are indistinguishable -only 1 allele dominant for each trait -only two phenotypes possible | 20 | |
| 1039766396 | what is incomplete dominance? what is an example? | neither allele is completely dominant over the other, and the F1 hybrids have phenotype somewhere between the 2 parental varieties ex.) red and white snapdragon can produce pink offspring | 21 | |
| 1039766397 | Is incomplete dominance an example of blending? | No, because they can also produce red or white offspring | 22 | |
| 1039766398 | what is co dominance? give example | alleles each affect the phenotype in separate, distinguishable ways -exhibited in a gene with more than two alleles -more than one allele may be dominant ex.) AB0 blood types | 23 | |
| 1039766399 | ABO blood types | type A: I^A I^A or I^A I^i type B: I^B I^B or I^B I^i type AB: I^A I^B type O: ii | 24 | |
| 1039766400 | Addition Rule for Probability | "either/or" -mutually exclusive events | 25 | |
| 1039766401 | Multiplication Rule for Probability | "and" -used for independent events | 26 | |
| 1039766402 | melanocytes | cells that make pigment | 27 | |
| 1039766403 | eye color with no pigment | blue | 28 | |
| 1039766404 | eye color with some pigment | hazel | 29 | |
| 1039766405 | eye color with a lot of pigment | brown | 30 | |
| 1039766406 | How many genes are involved in eye color? | at least 8 | 31 | |
| 1039766407 | what kind of genes are responsible for eye color? | OCA2 gene, EYCL3 gene, EYCL1 gene | 32 | |
| 1039766408 | OCA2 gene is responsible for.. | brown to blue spectrum -depends on how much OCA2 protein is made | 33 | |
| 1039766409 | EYCL3 (BEY2) gene | B=brown b=blue | 34 | |
| 1039766410 | EYCL1 (GEY) gene | G = green g = blue | 35 | |
| 1039766411 | why do people have 2 different eye colors? | 1.events in fetal development -some melanocytes are missing or non-functional 2. mosaicism -mutation early in development 3. injury | 36 | |
| 1039766412 | what is Epistasis? give an example | -when the phenotypic expression of a gene at one locus alters a gene at a second locus -involves 2 or more genes affecting one trait ex.) labrador coat color | 37 | |
| 1039766413 | B gene (labrador coat color) | for making hair pigment -B black -b brown | 38 | |
| 1039766414 | E gene (labrador coat color) | -for depositing hair pigment -E (color) -e (no color) -at least one copy of E is needed for dark colors | 39 | |
| 1039766415 | polygenic inheritance | the additive effect of two or more genes on a single phenotypic character -usually affects quantitative effects | 40 | |
| 1039766416 | quantitative character; ex) | a heritable feature that varies continuously over a range rather than in an either-or-fashion ex.) skin color | 41 | |
| 1039766417 | Effects of the environment ex.) | -environment can affect phenotype ex.) hydrangea flower color ranges from blue-violet to pink with the shade intensity of color depending on the acidity and aluminum content of the soil | 42 | |
| 1039766418 | pleitropy ex.) | -the ability of a single gene to have multiple effects ex.) PKU disease is caused by defective gene for phenylalanine hydroxylase | 43 | |
| 1039766419 | PKU disease | -converts phenylalanine to tyrosine -can cause mental retardation -eye color -skin color | 44 | |
| 1039766420 | Recessively Inherited Disorders; results in.. | -2 copies of recessive alleles are required -results in non functional protein or no protein | 45 | |
| 1039766421 | heterozygotes of recessively inherited disorders | -have normal phenotypes -make enough functional protein -serve as carriers for disorder | 46 | |
| 1039766422 | example of a recessively inherited disorder | albinism | 47 | |
| 1039766423 | albinism caused by.. | -defect in melanin production -tyrosinase is responsible for melanin production | 48 | |
| 1039766424 | dominantly inherited disorders | -only one copy of dominant allele required -heterozygotes have disease phenotype -dominant allele is rare in population -disease not as common | 49 | |
| 1039766425 | Anchondroplasia | -dominantly inherited disorder -dwarfism due to bone disorder -99.99% of population is homozygous recessive | 50 |
