Answer:
The correct answer is A) Histone deacetylation generally decreases gene expression.
Explanation:
Histones are the proteins that are responsible for the condensation of chromatin, which is directly linked to the capacity that a gene has to be expressed. The more condensed a gene is, the less expressible it becomes.
In order to regulate the gene expression, histones can suffer from many modifications that can change their conformation and the expressiveness of specific genes.
<u>Histone acetylation is linked with an increase of gene expression; while deacetylation and methylation decrease gene expression.</u>
Answer: A, B, and D
Explanation: I just took the test
Answer:
The correct answer is - as energy lost at every trophic level.
Explanation:
In any ecological ecosystem the energy pyramids always upright unlike other pyramids such as biomass showing the number of organisms, that can be diamond shape, inverted or upright.
The main reason behind this is due to the fact that it is only a pyramid in the ecosystem that always unidirectional in the food chain which is always some energy lost with an increase in the trophic level in the food chain. This loss of energy always gets back to the atmosphere in each step of the food chain.
Nutrients move through the ecosystem<span> in biogeochemical </span>cycles<span>. A biogeochemical </span>cycle<span> is a circuit/pathway by which a </span>chemical<span> element moves through the biotic and the abiotic factors of an</span>ecosystem<span>. It is inclusive of the biotic factors, or living organisms, rocks, air, water, and </span>chemicals<span>.</span>
Each time an organism is consumed, 90% of the energy is lost as heat. that leaves only 10% for the carnivore