The sun--solar energy--is at the heart of the cycle of life, with all the sustenance relationships referred to as the food web. The sun is the ultimate source of energy for animals, but its energy must be harnessed by plants before it can be used by animals. Animals get energy by processing complex foods.
The Sun cause That's What Gives it Food
The addition of acetyl groups to histones is associated with chromatin condensation and and higher levels of gene expression
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:
The result of cross two squashes with yellow seeds is an offspring of squash with green seeds -dominant caracter- heterozygous and yellow seeds squashes in a genotype proportion 1:2:1 and phenotype proportion 3:1
Explanation:
The cross of two heterozygous individuals for a characteristic results in an offspring that will have both characteristics in pure and heterozygous form. It is a cross monohybrid which complies with the principle of independent segregation exposed by Mendel.
For the characteristic "seed color" the green color would be G and yellow represented as g.
At the cross of two heterozygous squashs:
- Parents: Gg X Gg
- <u>Punnett's Square</u>:
Alleles G g
G GG Gg
g Gg gg
Offspring:
- A pumpkin of green seeds GG (25%)
- Two pumpkins of green heterozygous seeds Gg (50%)
- One pumpkin of yellow seeds gg (25%)
Genotype proportion 1:2:1
Phenotype proportion 3:1
