Genetic Crosses Problems

Multiple Choice

In a monohybrid cross between two heterozygous parents (Aa x Aa), what is the probability of producing an offspring with a homozygous recessive genotype?

• 25%

• 50%

• 75%

• 100%

Multiple Choice

A heterozygous long-tusked elephant is crossed with a homozygous recessive short-tusked elephant. What is the probability of the offspring having short tusks?

• 0%
• 25%
• 50%
• 75%

Multiple Choice

In pea plants, tall (T) is dominant over short (t). If two heterozygous tall pea plants are mated, what is the the expected genotypic ratio of their offspring?

• 3 tall : 1 short

• 1 TT : 2 Tt : 1 tt

Multiple Choice

What are the phenotypic ratios of the offspring in the dihybrid test-cross TtYy X ttyy?

• Tall, yellow

• Tall, green

• Dwarf, yellow

• Dwarf, green

Multiple Choice

In a dihybrid cross of TtYy x TtYy, what is the expected phenotypic ratio of the offspring?

• 9 tall plants with yellow seeds

• 3 tall plants with green seeds

• 3 dwarf plants with yellow seeds

• 1 dwarf plant with green seeds

Fill in the Blanks

Multiple Choice

What is the predicted ratio of offspring for yellow, round x green, wrinkled using the forked-line method?

• 9/16 yellow, round

• 3/16 green, round

• 1/16 green, wrinkled

• 3/16 yellow, wrinkled

Multiple Choice

What are the combined phenotypes of the three genes in the forked-line method for the given cross?

• 27 tall, yellow, round

• 9 tall, yellow, wrinkled

• 3 dwarf, green, round

• 1 dwarf, green, wrinkled

Multiple Choice

Genetics problem that crosses 2 traits:

• Monohybrid Cross
• Dihybrid Cross
• Multiple Alleles
• Incomplete Dominance

Multiple Choice

The chart shows a dihybrid cross between pea plants. What are the genotypes of the parents in this cross?

• RRyy and rrYY

• RrYy and RrYy

• RRYY and rryy

• RrYY and Rryy

Multiple Choice

What are the combined phenotypes of the three genes in the testcross?

• 1 tall, yellow, round

• 1 dwarf, yellow, round

• 1 tall, green, round

• 1 dwarf, green, round

Multiple Choice

What is the combined proportion of the phenotype represented by ABC in the trihybrid cross?

• 27/64

• 9/64

• 3/64

• 1/64

Multiple Choice

In pea plants, tall (T) plant alleles are dominant to short (t) plant alleles. If two tall plants (each with the genotype Tt) are crossed, what is the probability that the cross would result in a short pea plant?

• 25%

• 50%

• 75%

• 100%

Multiple Choice

The principles of probability can be used to

• predict the traits of the off spring of genetic crosses

• determine the actual outcomes of genetic crosses

• determine which species should be used in genetic crosses

• decide which organisms are best to use in genetic crosses

Multiple Choice

What role do genetic counselors play in predicting the likelihood of having an affected child?

• They provide medical treatment

• They predict the future with certainty

• They help couples understand genetic risks

• They decide if couples should have children

Multiple Choice

What is the formula for calculating probability?

• Probability = Number of events / Total events

• Probability = Total events / Number of events

• Probability = Number of successful events / Total events

• Probability = Number of times an event occurs / Total number of events

Multiple Choice

What is the probability of two heterozygotes (Gg) producing an offspring that is GG?

• 1/2

• 1/4

• 1/3

• 1/5

Multiple Choice

What is the impact of sample size on the accuracy of probability predictions?

• Larger sample sizes lead to more accurate predictions

• Smaller sample sizes lead to more accurate predictions

• Sample size has no impact on accuracy

• Sample size only affects predictions in specific cases

Multiple Choice

As your sample size of an experiment increases, what should happen to the p-value of the data?

• It will increase

• It will decrease

• It will remain constant

Multiple Choice

n

• mean

• standard deviation

• mode

• Sample Size

Multiple Choice

What are the three mathematical operations used to compute probability?

• Sum rule

• Product rule

• Binomial expansion equation

• Addition rule

Multiple Choice

The symbol  $$\Sigma$$  means

• sample mean

• square root of all values

• sum of all values

• sample size

Multiple Choice

What is the formula for the Additive/ Sum Rule in probability?

• P(A) + P(B) - [P(A) × P(B)]

• P(A) + P(B) + [P(A) × P(B)]

• P(A) - P(B) + [P(A) × P(B)]

• P(A) + P(B) - P(A) - P(B)

Multiple Choice

What is the Additive Rule in probability?

• P(A) + P(B)

• P(A) × P(B)

• P(A or B) = P(A) + P(B)

• P(A and B) = P(A) + P(B)

Poll

How confident do you feel about this topic now?

• Very confident
• Somewhat confident
• Not confident