3. The figure below shows a photomicrograph of a cross section of an artery from a mammal.
M
a) Measure the diameter of the lumen (the hole in the middle of the artery between
points X and Y. Include the unit.
(1pt)
Diameter of the lumen
b) Measure the diameter of the lumen (the hole in the middle of the artery between
points M and N. Include the unit.
(1pt)
Diameter of lumen M and N

Two male mice, which we will call male a and male b, are both phenotypically normal. male a was from a litter that contained half phenotypically normal mice and half dwarf mice. the mother of male a was known to be homozygous for the normal igf2 allele. male b was from a litter of eight mice that were all phenotypically normal. the parents of male b were a phenotypically normal male and a dwarf female. male a and male b were put into a cage with two female mice that we will call female a and female b. female a is a dwarf and female b is phenotypically normal. the parents of these two females were unknown, although it was known that they were from the same litter. the mice were allowed to mate with each other, and the following data were obtained: female a gave birth to three dwarf babies and four normal babies. female b gave birth to four normal babies and two dwarf babies. which male(s)mated with female a and female b? male a with both females male a with female b, and male b with female a male a with female a, and male b with female b could not be determined male b with both females

Anita thinks that she has heterozygous alleles for red hair. if she is correct, which of these diagrams best illustrates anitas alleles pf red hair

What does the number 18.9984 represent in the image?