Answer:
Bridgham et al. (2006) showed that the interaction between a steroid hormone (aldosterone-M) and its receptor (mineralocorticoid) evolved by Darwinian gradualism. In this work, the authors demonstrated a primitive affinity between the hormone and its receptor that was initially present in chemically similar but more ancient ligands. This result has implications in understanding the association between gene duplication and the evolution of hormone signaling pathways. For example, in invertebrates, this work reinforces the importance of gene duplication in the existing interaction between paralogous glucocorticoid receptors and their receptor mineralocorticoid genes that were derived from duplication (Thornton 2001).
The publications above cited are the following:
J.T. Bridgham, S.M. Carroll, and J.W. Thornton (2006). Evolution of hormone-receptor complexity by molecular exploitation. Science, 312(5770), 97-101.
JW Thornton. Evolution of vertebrate steroid receptors from an ancestral estrogen receptor by ligand exploitation and serial genome expansions, Proc Natl Acad Sci USA (PNAS), 2001, vol. 98 10 (pg. 5671-5676).
Answer:
B
Explanation:
Cooling reduces the excitement of the molecules of the DNA hence allowing the hydrogen bonds between the base pairs of the two strands to form hence the DNA is considered to anneal. Heating disrupts the hydrogen bonds and causes the two strands to dissociate.
1.Frost Wedging (Freeze-Thaw)
Water expands by 9 percent when it freezes. As it expands, it exerts up to 4.3 million pounds per square foot of pressure. Since water seeks low points, repeated freezing and thawing can lead to deep vertical fissures as cracks are extended downward. Cracks that allow entry of roots lead to similar wedging.
2.Crystal Formation
Crystal formation cracks rock in a similar way. Most water contains dissolved salts. When water in rock fissures evaporate, the salt concentration increases, which leads to crystallization. This occurs in arid regions where the humidity fluctuates widely, so that the salt can be redissolved and carried into new fissures.
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Answer:
Qualitative: moister, taller, and darker shade.
Quantitative: 0.25-0.5 cm taller, how many cupcakes she could make.
Explanation:
Qualitative is observation based and Quantitative is mathematical based (i.e. measuring, etc.)
Cell is limited in size for many reasons. Cells wouldn't be respire effectively if it were too large, because the surface area to the volume ratio would be too small.
The other thing is that if the cell were too large, it would be difficult for it to move nutrients and waste products in and out of the cell. So, cells are limited in size.
