In e. coli, four Hfr strains donate the following markers, shown in the order donated:
Strain 1: M Z X W C
Strain 2: L A N C W
Strain 3: A L B R U
Strain 4: Z M U R B
All these Hfr strains are derived from the same F+ strain. What is the order of these markers on the circular chromosome of the original F+?2 AnswersBiology1 decade ago
In corn, small pollen (sp) is recessive to normal pollen (sp+) and banded necrotic tissue, called zebra necrotic (zn), is recessive to normal tissue (zn+). The genes that produce these phenotypes are 12 m.u. (map units) apart on chromosome 10. If crossing over occurs between these two loci, give the types of progeny expected from the following crosses: 1) sp+ zn+ / sp zn X sp zn / sp zn
2) sp+ zn / sp zn X sp zn / sp zn
In soreflies (a hypothetical insect), the dominant allele L, is responsible for the resistance to a common insecticide called Loritol. Another dominant allele, M, is responsible for the ability of soreflies to sing like birds. A true-breeding mute, Loritol resistant sorefly was mated to a true-breeding singing, Loritol sensitive sorefly, and the singing, Loritol resistant femlale progeny were test crossed with true-breeding wild-type (i.e., mute, Loritol sensitive) males. Of the 400 total progeny produced, 117 were mute and Loritol resistant, 114 could sing and were Loritol sensitive, 83 could sing and were Loritol resistant, and 86 were mute and Loritol sensitive. Do you think the (L) and (M) gene loci are linked or unlinked? Justify your answer.
When a yellow female Labrador retriever was mated with a brown male, half the puppies were brown and half were yellow. The same female, when mated with a different brown male, produced only brown offspring. Explain these results.3 AnswersBiology1 decade ago
E.W. Lindstrom crossed two corn plants with green seedlings and obtained the following progeny: 3583 green seedlings, 853 virescent-white seedlings, and 260 yellow seedlings. Give the genotypes for the green,virescent-white, and yellow progeny.2 AnswersBiology1 decade ago
A variety of opium poppy having lacerate leaves was crossed with a variety with normal leaves. All the F1 had lacerate leaves. Two F1 plants were interbred to produce the F2. Of the F2, 249 had lacerate leaves and 16 had normal leaves. Give the genotypes for all the plants in the P, F1, and F2 generations. Explain how lacerate leaves are determined in the opium poppy.3 AnswersBiology1 decade ago
1) Indicate the probability of each of the following:
a) 4 girls
b) 3 girls, 1 boy
c) 2 girls, 2 boys
d) 1 girl, 3 boys
e) 4 boys
2) What would be the porbability of 3 girls and 3 boys being born on the same day?
3) If AaBb is mated toAaB, what is the porbability that the offspring will be each of the following:
a) either AABb or AaBB?
b) either AaBb or aaBb?
c) either Aabb or aaBB?
d) either AABB or aaBB?
e) either phenotype A-B-or phenotype aaB-?