A monohybrid cross looks at

A monohybrid cross looks at a single trait.

Explanation:

Monohybrid cross happens between two organisms who have variations in the traits. The alleles will be either dominant or recessive. It is generally done in first filial generation which differ in one trait. In this cross single gene controls the single traits as two variants.

Monohybrid cross is useful in knowing the dominant character of an allele.

A cross between short pea plant and tall pea plant.

Tall TT = Dominant

tt short = recessive

Punnet square:

  T    T

t  Tt   Tt     parental generation

t  Tt  Tt

for F1 GENERATION cross between parental generation:

    T   t

T TT  Tt

t  Tt   tt      3:1 is the phenotype ratio

It can be concluded that tall is the dominant trait expressed. This is law of Dominance.

the correct answer is:

a population changes in response to a change in the environment.

the statements that apply here about binary star system are

"have stars that might appear to wobble"

"often have one star that is brighter than other"

a binary star is a star system consisting of two stars revolving around their common barycenter. systems of two or more stars are called multiple star systems.