An orange roughy fish is a fourth-level consumer that requires almost ten times the amount of food available from the primary producers in the ecosystem. why isn't more energy available from the primary producers?

a. primary producers are not very efficient and lose most of their energy to the environment.
b. there is too much competition from other fourth-level consumers, leaving very little available to the orange roughy.
c. only a fraction of energy is passed through each level, so there is less available to upper-level consumers.
d. the energy flow is unbalanced and tends to move toward the lower levels.

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

In the water cycle , when does water undergo a chemical change

Creating new things to solve problems and improve life depends on the close interaction of which two fields?