Punnett squares are used to find out the possible genotypes of the next generation after a cross and thus find the phenotype too according to the predicted genotypes.
For example, parents with genotypes of Rr and rr cross together, we can use the punnett square to list out the possible genotypes of their children which are Rr and rr.
You can never predict the exact genotypes of the next child but you can find out the possibility if they carry a certain trait. All the genotypes of the child are in random but you at least know what phenotypes they'll have.
Parents: Homozygous brown-eyed (M) -
B B blued-eye (F) -
b b [since blue (b) is recessive then and brown (B) is dominant then
in order for the blue gene to
show the you need double recessive or the brown
gene absent
Offspring:
So based on the Punnett cross then you realize that all the possible of spring carry the
genotype B b and as such the
phenotype brown eyes
Coal from swamp plants that formed millions of years ago.
The object we would need to measure force
is a spring scale
Kinda like a pyramid. The bottom is wide, many sources of energy (plant life) that take nutrients combine them with water use the bonding of the suns rays and convert that to matter. This matter is then consumed by animals (grazers and browsers), who in turn are fed upon by predators. With man as the top predator.
Take a few seeds from wire-grass. Wire-grass grows in many natural communities, it is eaten by rodents and birds, like Quail. Quail are eaten by snakes, who are eaten by hawks, bobcats, and raccoons.
every time the meal is transferred from one critter to the next, energy is expended in the chase (heat) and capture, and energy is always being used for the animals to survive day by day.