Answer:
Explanation:
zinc zn 30 65.38 u 30 34 30
<h2>Energy </h2>
Explanation:
Energy flows in only one direction through an ecosystem
- The Sun supports most of Earth's ecosystems
- Plants create chemical energy from abiotic factors that include solar energy and chemosynthesizing bacteria create usable chemical energy from unusable chemical energy
- The food energy created by producers is passed to consumers, scavengers, and decomposers
- Energy flows through an ecosystem in only one direction, it is passed from organisms at one trophic level or energy level to organisms in the next trophic level
- Most of the energy at a trophic level – about 90% – is used at that trophic level and organisms need it for growth, locomotion, heating themselves, and reproduction
- So animals at the second trophic level have only about 10% as much energy available to them as do organisms at the first trophic level
- Animals at the third level have only 10% as much available to them as those at the second level
The correct answer is: b. It is free to bind to another promoter and begin transcription
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex.
RNA polymerase is also released and can transcribe some other gene by binding to its promotor. RNA polymerase will transcribe just the genes whose products are needed at a particular moment.
Pathogens can exist in blood and then can be passed the transfusions
Answer:
Millions of years ago, the Appalachians were taller than the Himalayas! Millions of years of erosion, however, have taken their toll. ... The crust that is now the Appalachians began folding over 300 million years ago, when the North American and African continental plates collided.
