Germ layer is a primary layer of cells found in the embryo. The three primary germ layers that generate most of the cells in the developing mammalian forelimb are ectoderm, mesoderm and endoderm.
Ectoderm forms the outer component of a mammalian body such as skin, hair, etc. Endoderm forms the inner layer that comprises of the linings of digestive system, lungs and thyroid. Mesoderm is the middle layer that forms the skeletal system, heart, etc.
Neural tube is generated by the inward folding of the ectoderm. This process is called neurulation. Ectoderm also forms neural crest.
1. Like living things, viruses have genetic material and 2. viruses can evolve.
- Viruses share many genes with their host cells. Viruses are dependent on living organisms, which lead to some living characteristics - they can reproduce/replicate in living host cells, mutate, appear in different strains, and have unique genetic material. However, viruses are classified as not living things because they can’t carry out the necessary processes that meet all requirements for the classification of a living thing. They do NOT undergo respiration and cannot generate energy needed to survive on its own, but viruses *do* share a few features with living things.
Contain circular pieces of DNA concentrated within a nucleoid. Some contain plasmids, which can<span> be shared with other </span>prokaryotes<span>. </span>Eukaryotes<span> contain </span>their<span> genetic material in chromosomes within a nucleus. ... </span>Prokaryotes<span> are therefore able to lack membrane-bound organelles and have less complex internal </span>structure<span>.</span>
