Read the passage below. “Prior to the 1970s, scientists thought that new neurons could not be generated in adult brains. In the 1970s,
Dr. Goldman and Dr. Nottbohm discovered that hormones injected in adult songbirds could cause female
songbirds to develop new neurons.”
Which statement best exemplifies the scientific principle that was involved in this case?
New experiments do not affect science because science remains constant.
New experiments can affect future scientific explanations.
New experiments can affect previous scientific explanations.
New experiments yield untrustworthy data and should be carefully considered.

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)

Choose one animal (cheetas) and research on the internet what has contributed to this animal becoming "endangered" or "threatened." what animal you have chosen? how long has the animal been endangered or threatened? what has contributed to this animal’s endangered or threatened status? why is it important to save this animal from extinction? after researching and gathering facts, write a 350-word letter from the point of view of an animal rights' activist. be sure to include at least five facts that you learned from your research.

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?