Describe the blending theory of heredity and how Mendel's results help to reject this theory
What will be an ideal response?
The blending theory viewed the traits of progeny as a mixture of the characteristics possessed by the two parental forms. Under this theory, progeny were believed to display characteristics that were approximately intermediate between those of the parents. Mendel reasoned that if the blending theory were true, he would see evidence of it in each trait. If no blending were seen in individual traits, the blending theory would be disproved. F1 experimental results reject the blending theory of heredity because all F1 progeny have the same phenotype (i.e., the dominant phenotype) that is indistinguishable from the phenotype of one of the pure-breeding parents. This specifically contradicts the blending theory prediction that the F1 would display a mixture of the parental phenotypes. The persistence of the dominant phenotype and the reemergence of the recessive phenotype in the F2 also contradict the blending theory.
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A genetic element which can replicate autonomously when introduced into a cell grown in culture is a ________
Fill in the blank with correct word.
In humans, the genetic basis for determining the sex "male" is accomplished by the presence of ________
A) high levels of estrogen B) a balance between the number of X chromosomes and the number of haploid C) a portion of the Y chromosome D) multiple alleles scattered throughout the autosomes E) one X chromosome F) sets of autosomes
Chemical reactions are classified as exergonic if ________
a. they involve gain or loss of atoms b. they need a boost of energy to begin c. they end with a net release of energy d. the bonds in the reactants have more energy than the bonds in the products
The extracellular matrix is composed of: (1) proteins; (2) polysaccahrides; (3) nucleic acids
A. Statement (1) is correct. B. Statement (2) is correct. C. Statement (3) is correct. D. Statement (1) and (2) are correct. E. All the statements are correct.