Answer:
B. Enough trees to create a close canopy.
Explanation:
Forests may have several tree species but one very important feature of forests is their close canopy of dense trees, often arranged in several strata (or layers).
Limestone contains calcium carbonate which comes from animals that have shells, it already has carbon. Other sources are ocean animals which create shells that combine both carbon and calcium. Their dead bodies also release carbon to the ocean. Limestone is also known as a sedimentary rock that has carbon. Outside the ocean, limestone emits the carbon and becomes part of the carbon cycle. In addition to this, limestones are widely used by people becomes a part of the carbon cycle. Its component is present on asphalt, animal feed.
Insect hormones and their receptors are a focus in pest control and research. Hence, Option B is correct.
Some of the insect hormones such as ecdysone (molting hormone), JH (juvenile hormone) and their analogs can be used for biological control of pests.
Option A: Hormone receptors are proteins that bind hormones and form hormone receptor complex to maintain cellular activities.
So Option A is incorrect.
Option B: Some of the peptide hormones used in pest control and research. So Option B is correct.
Option C: Peptide hormones interact with only cell surface whereas aminoacid derivatives and thyroid hormones directly interact with nucleus. so Option C is incorrect.
option D is incorrect.
Learn more on hormone receptor complex here:
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Explanation:
AswerB
hydrogen, helium and lithium
It took 380,000 years for the electrons to be trapped in orbits nuclei forming the first atoms. (which is option B)