It should be an igneous rock because it formed by the volcanoes lava cooling down
Answer:
The organism's parents have to either be heterogeneous dominant or homogeneous.
Explanation:
When the traits get passed down they either have to have 2 dominant traits or a mix.
Answer:
Oxygen levels stay above 15 percent starting 200 million years ago
Explanation:
Atmospheric oxygen levels are related to the evolution on Earth and changes in geochemical cycles that involve climate variations.
The presence of O
2 and evolution of oxygen gave new opportunities to the life on Earth. Oxygen levels in atmosphere have fluctuated between 15% and 35% of atmospheric volume, since the start of the Cambrian period.
So, form the starting 200 million years ago, oxygen level stay above 15 percent and the correct option is "B".
A bacterium has a faulty lac operon in which there is a structural defect in the operator. In this bacterium there is a structural problem with a segment of DNA that binds a repressor.
- A protein known as a repressor binds to an operator site. The operator in this instance (and numerous others) is a section of DNA that lies just downstream of the RNA polymerase binding site or overlaps with it (promoter). In other words, it lies between the operon's promoter and its genes.
- The repressor protein inhibits the synthesis of messenger RNA by attaching to the promoter region of the gene(s) (mRNA). The control of gene expression in cells requires repressor proteins.
- Thus, by physically impeding the RNA polymerase's ability to operate, these repressor proteins stop the gene from being transcribed.
To learn more about DNA.
brainly.com/question/316480
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