Molecular/structural orientations (gradients) in an egg are thought to play a significant role in development. What is the origin of such gradients? What evidence indicates that the maternal genotype is involved in providing such gradients?
What will be an ideal response?
In examples of maternal effects, the mother's genotype establishes the early body plan. During formation of any egg, nutritional, regulatory, and informational molecules (RNAs) are placed in appropriate positions for development of the embryo. Many maternal-effect genes have been identified in Drosophila.
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Which of the following is not a eukaryotic retrotransposon?
A. gypsy B. Ty elements C. LINEs D. SINEs E. Tc1/mariner
Ribosomes are very old structures, found in all organisms (except viruses), from bacteria to humans. As a result, molecular taxonomists are looking at relationships based upon which rRNA sequence(s)?
A) 16S B) 18S C) 30S D) both choices A and B E) all of the above
The breast muscle of turkeys and chickens is usually referred to as light meat, whereas that of wild ducks and geese is described as dark meat. How might this be explained?
A. Turkeys and chickens are not closely related to ducks and geese. B. Turkeys and chickens do not fly for sustained periods, whereas wild ducks and geese do. C. The muscles of ducks and geese do not contain myosins. D. The darker body color of ducks and geese provides protective camouflage against predators.
Jorge has developed prostate cancer, so he undergoes an operation to remove the malignancy. What other structures will the cancer specialists look at to check for metastasis?
A) local arteries B) connecting veins C) neighboring lymph nodes D) portions of the liver