Exam 23: Patterns of Gene Inheritance

Computer simulations are sometimes used to demonstrate the outcome of monohybrid fruit fly crosses,where a student can run generation after generation of fruit flies with 100 offspring produced each generation,half male and half female,and a 3-to-1 phenotype ratio (or 75 to 25)in the F₁ generation.Compared to real genetics results,which of the following is NOT true?

In peas,yellow is dominant over green in seeds.With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous?

In which kind of cross would you expect to find a ratio of 9:3:3:1 among the F₂ offspring?

The _____ indicates the gene combination of an individual.

To try and discover if the environment has an effect on a particular characteristic scientists often examine

Mendel's law of segregation implies that the two members of an allele pair

In horses,black coat (B)is dominant over brown coat (b),and being a trotter (T)is dominant over being a pacer (t).A black horse who is a pacer is crossed with a brown horse who is a trotter.The offspring is a brown pacer.What is the genotype of the brown trotter parent?

In humans,widow's peak (W)is dominant over straight hairline (w).If a heterozygous male marries a female with a straight hairline,what percent of their children can be expected to have widow's peak?

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.Two heterozygous individuals reproduce.The expected results are

The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability.The standard assumption is that tongue-rolling is a dominant allele at a single gene locus.Which of the following would cast doubt on this assumption?

Which of the following crosses will yield only homozygous recessive offspring?

The four o'clock flower is an example of incomplete dominance: R = red,r = white,and Rr = pink.If two hybrids are crossed,what are the chances that an offspring will have pink flowers?

A cross is made between two parents with genotypes AaBB and aabb.If there are 32 offspring,how many of them would be expected to exhibit both dominant characteristics?

Traits that are controlled by several sets or pairs of alleles,such as skin color and height in humans,are the result of what form of inheritance?

Mr.X has been accused by Miss Z of fathering her child.The child's blood type is AB and Miss Z's blood type is A.Mr.X could NOT be the father if his blood type is

In guinea pigs,B = black,b = brown,S = short hair,s = long hair.A heterozygous black,shorthaired animal reproduces with a brown,longhaired animal.What is the expected phenotypic ratio of the offspring?

If an albino (recessive)woman is married to a man with normal coloring and they have an albino child,what was the genotype of the man?

Since each child of two heterozygous parents has a 1/4 chance of receiving a recessive trait from each parent,

If pairs of factors separate independently of other pairs of factors,you are dealing with the

Which of the following is an autosomal dominant disorder?