Explanation:
Trophic levels is known as feeding levels in an ecosystem.
Trophic levels is any of the stages involved in the food chain. In an ecosystem, the trophic levels begins with the producer which provides foods from inorganic sources.
- Consumers at all levels feeds on the food produced by the producers. Some consumers feeds on other consumers.
The most common blood type in the US population is O-positive with 38% of the US population
Answer:
Housekeeping genes may be defined as the genes that are constitutive genes important for the cellular functioning of the organism. The expression of housekeeping gene may or may not vary.
Some housekeeping genes are not expressed at same level because the housekeeping genes also have different promoters. The different promoters have different affinity to interact with the holoenzyme of RNA polymerase.
The answer is: Ecological Succession
STEPS:
1.) Bare rock (there is no grass at this point).
2.) Lichens (lichens begin to appear).
3.) Small Plants & Lichens (small plants begin to grow & the lichens are spreading).
4.) Grasses (grass starts to grow in certain spots).
5.) Shrubs & Grasses (the grass has covered, at least the majority, of the ground and shrubs begin to appear).
6.) Trees (the shrubs have grown into trees that are tall enough to provide shade)
7.) Animals (the animals return or new animals appear).