In an experiment, 6,000 people with a common cold who drank orange juice daily had symptoms that lasted an average of 4 days. Another 6,000 people with a common cold who did not drink orange juice daily had symptoms that lasted an average of 7 days. Scientists repeated the experiment 3 times with the same results. They concluded that orange juice reduces the length of the common cold. Was this conclusion valid, and why?

Coat color in cats is determined by genes at several different loci. at one locus on the x chromosome, one allele (x ) encodes black fur and another allele (xo) encodes orange fur. females can be black (x x ), orange (xoxo), or a mixture of orange and black called tortoiseshell (x xo). males are either black (x y) or orange (xoy). bill has a female tortoiseshell cat named patches. one night, patches escapes from bill\'s house, spends the night out, and mates with a stray male. patches later gives birth to the following kittens: one orange male, one black male, two tortoiseshell females, and one orange female. what are the genotypes of patches, the stray male, and the kittens?

19. a cell is viewed under a microscope and is found to have two nuclear envelopes and spindles that appear to be breaking apart. which phase of mitosis is the cell most likely in? a. metaphase b. prophase c. telophase d. anaphase

Explain what a zygote is. use the terms egg cell, sperm cell, and fertilization in your explanation.