Unit 8 Bio Test Flashcards
Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. What is the explanation behind this?
environmental factors such as soil pH levels
Which of the following is an example of polygenetic inheritance?
A) pink flowers in snapdragons
B) skin pigmentation in humans
C) the ABO blood groups in humans
D) Huntington’s disease in humans
E) white and purple flower color in pease
B) skin pigmentation in humans
When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?
50%
Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests ______________.
that the parents were both heterozygous
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). It's genotype is HhTt. Which is a possible genotype in a gamete from this organism? A) tt B) HhTt C) HT D) Hh E) T
C) HT
A woman has six sons, what is the chance that her next child will be a girl?
1/2 (50%)
A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. What is a possible genotype for the mother?
IAi
What described the ABO blood group system?
multiple alleles
A pedigree analysis of a given disorder’s occurrence in a family shows that, although both parents of an affected child are normal, each of the parents has had affected relatives with the same condition. That makes this disorder __________.
recessive
Two characteristics that appear in a 9:3:3:1 ratio in the F2 generation should have what property?
the genes controlling the characters obey the law of independent assortment
Mendel accounted for the observation than traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that ________________.
traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1 generation
Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assert independently. 1,000 F2 offspring resulted from the cross, approximately how many then would have red, terminal flowers?
190
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long talks (t). What fraction of the progeny of the cross BbTt x BBtt will have black fur and long tails?
1/2 (50%)
In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red: 2 roan: 1 white? A) roan x roan B) white x roan C) cannot be determined D) red x roan E) red x white
A) roan x roan
______________: having two different alleles for a gene
heterozygous
