The following options are all reproductive barriers. which one is an example of a prezygotic barrier in which the two different species do mate?
1 two crayfish species cannot interbreed because their genitalia do not engage properly with each other.
2 hybrid mules produced by mating donkeys and horses are sterile.
3 one bird species lives in wetlands, the other in dry forests; hence, they do not encounter each other.
4 two dragonfly species regularly mate, but their gametes are incompatible.

Idont understand by supporting the plant and holding the leaves up to the light. question 3 options: tap or fibrous root flower petals herbaceous or wood stems leaves with stomata

Considering the yellow and green pea color phenotypes studied by gregor mendel: a. what is the biochemical function of the protein that is specified by the gene responsible for the pea color phenotype? (1 point) b. a null allele of a gene is an allele that does not specify (or encode) any of the biochemical function that the gene normally provides (in other words, either no protein at all or only non-functional protein is produced from it). of the two alleles, y and y, which is more likely to be a null allele? (1 point) c. in terms of the underlying biochemistry, why is the y allele dominant to the y allele? (2 points) d. why are peas that are yy homozygotes green? (1 point) e. the amount of protein produced from a gene is roughly proportional to the number of functional copies of the gene carried by a cell or individual. what do the phenotypes of yy homozygotes, yy heterozygotes, and yy homozygotes tell us about the amount of sgr enzyme needed to produce a yellow color? explain your reasoning. (2 points)

Jason, a dog breeder, decides to mate a poodle with a golden labrador retriever. he wants to get puppies with the curly hair of the poodle and the color of the labrador. what concept is shown in this example? question 6 options: artificial selection adaptation evolution natural selection