Answer:
Sigma factors bind to the promoter region of a particular gene and facilitating the binding of RNA Polymerase to the promoter region (formation of the RNA polymerase holoenzyme complex) in order initiate transcription of the gene. 
Put simply - Helps RNA Polymerase do it's job. 
 
        
             
        
        
        
Aquatic organisms have external fertilization and reproduction is done through mating of male and female.
<h3>How do aquatic vertebrates reproduce?</h3>
All vertebrates reproduce through mating of male and female. Aquatic species generally have external fertilization, whereas terrestrial species usually have internal fertilization.
In conclusion, aquatic organisms have external fertilization and reproduce through mating of male and female.
Learn more about vertebrates here: brainly.com/question/10714806
 
        
             
        
        
        
Answer:
Chlorophyll is any of several related green pigments found in the mesosomes of cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words χλωρός, khloros and φύλλον, phyllon. Chlorophyll is essential in photosynthesis, allowing plants to absorb energy from light.
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Answer: See below
Explanation:
Solar energy: Advantages: Solar energy is pollution free and causes no greenhouse gases to be emitted after installation. Disadvantages: Although solar energy can still be collected during cloudy and rainy days, the efficiency of the solar system drops.
Wind energy: Advantages: It doesn't pollute air like power plant relying on combustion of fossil fuel. Disadvantages: Wind turbines can be a threat to wildlife (e.g. birds, bats).
Hydroelectric energy: Advantages: Hydroelectric energy is fueled by water, so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels, such as coal or natural gas. Disadvantages: Electricity generation and energy prices are directly related to how much water is available. A drought could potentially affect this.