What of the following is an example of a post-zygotic reproedutive barrier?
a. one lilac species lives on acid soil, another on basic soil
b. mallard and pintail ducts mate at different times of the year
c. two specieis of leopard frogs have different mating cells
d. hybrid offspring of two species of jimonweed always die before reporducing
Here is the answer:
Answer: d. hybrid offspring of two species ...
The solution comprised of an objective type question in detail.
Four short answer questions that pertain to a pericentric inversion that results in reduced fertility. Ideograms of the inversion and a crossover events are also needed.
A female has suffered five consecutive miscarriages.Cytological study of her peripheral blood revealed 46,XX inv(1) (p32 q34) in all her cells and inversion (9) (p12 q12) in 30% of the studied cells. It is likely that the chromosome 1 abnormality is the cause of the woman's recurrent miscarriages.
a) Explain in words the nature of the woman's chromosome 1 abnormality.
b) Find an ideogram of human chromosome 1 and DRAW with key landmarks, the woman's chromosomes 1, paired during oogenesis' first meiotic prophase. LABEL key landmarks.
c) Suppose in 70% of meiosis there is a crossover somewhere in the region between bands p32 and q34. DRAW the gametic chromosomes 1 that would result from meiosis in which a single crossover occurred within band q 1.1.
d) What fraction of the gametes are likely to give rise to normal development, if the chromosome 1 abnormality is the only cause of gametic/zygotic non-viability?View Full Posting Details