Genetic Crosses

In cacti, long arms (A) are dominant to short arms (a).  Suppose 2 heterozygous cacti are crossed.  What percentage of their offspring are expected to have short arms?

• 0%
• 25%
• 75%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

If a heterozygous tall pea plant is crossed with a short pea plant, what are the possible genotypes of the future offspring?

• 100% Tt
• 50% Tt, 50% tt
• 75%Tt, 25%tt
• 25%TT, 50%Tt, 25%tt

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

What goes in box 1

• AABb

• ABAb

• aabb

• AaBb

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What is the correct phenotype ratio when crossing two heterozygous parents in a dihybrid cross?

• 100% heterozygous

• 1:2:1

• 3:1

• 9:3:3:1

Cross Two Homozygous plants
(RRYY x rryy)
R = round seeds, r  = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds? 

• 0%
• 25%
• 50%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

T4 - Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What percentage of the offspring of the cross BbTt x BBtt will have black fur and long tails?

• 0%
• 25%
• 50%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

A plant shows incomplete dominance in size. A tall plant (TT) is crossed with a medium plant (TS). What fraction of plants will also be tall?

• 100 %
• 75%
• 50%
• 25%

Tags

NGSS.HS-LS3-3

A roan cow shows co-dominance in fur color (orange and white). What is the phenotype ratio expected if a roan cow and a roan steer mate together?

• 4: Orange and White
• 1: Orange : 1 White
• 2 Orange: 2 Orange and White: 0 White
• 1: Orange: 2 Orange and White: 1 White

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Snap dragon color is a incomplete dominant trait.  A red flower (RR) is crossed with white flower (rr)? What color are flowers that are Rr?

• Red
• Red and White
• White
• Pink

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In a cross between a pure red eyed female and a white eyed male, what would the genotypes of the parents be?

• X^RX^r with X^R Y

• X^RX^r with X^r Y

• X^RX^R with X^R Y

• X^RX^R with X^r Y

• X^rX^r with X^r Y

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2