Suppose you have monohybrid snapdragons in your garden and you find that they produce red seeds to white seeds in the ratio of 3: 1. if the alleles are designated r (red seeds) and r (white seeds), what are the probable phenotypes of the parents (p1)?
half red and half white
all white
all red
unable to determine

The parents (P1) will be all red. The monohybrid snapdragons producing red and white seeds in the ratio of 3:1 with the red (R) phenotype being dominant and white(r) being recessive, might possibly have the  parents with the following genotypes:

Rr (Red)                  Rr (Red)

The gametes produced by these parents will be R and R. The cross of these parents (P1) will result in the following generation that will be in the ratio of 3:1 (red:white) :

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.