I believe the correct answer is "Carbon dioxide"
<span>Embryonic tissues or germ layers develop during the gastrulation stage.</span> <span>Gastrulation is a process in embryonic development during which the single-layered blastula is reorganized into a three-layered(or two-layered) structure called the gastrula. <span>Two primary germ layers(embryonic tissues) are an inner layer-endoderm and an outer layer-ectoderm. Endoderm and ectoderm interact and produce a third layer-mesoderm. Gastrulation is followed by organogenesis, three germ layers will give rise to specific tissue and organ.For example, ectoderm gives rise to epidermis and nervous system, endoderm to the digestive system and mesoderm to muscles, bones…</span></span>
Ultraviolet or all wavelengths
<span>The answer is nuclear imaging. A subject is asked to take in a radionuclide (radioactive
isotopes) and as the radioactive material passes though the body, it continually emits radiation that is detectable by an instrument such as a gamma camera. Examples of nuclear imaging
techniques are SPECT and PET.</span>
<span>
the tissue in higher plants that constitutes the vascular system, consisting of phloem and xylem, by which water and nutrients are conducted throughout the plant.</span>