a. digestive and excretory systems.
Answer:
Forebrain.. Which also includes thalamus.
I think the correct answer would be the first option. It is the carbohydrates that is used as markers by cells to help recognize each other. Sugar chains are being used by the cells which are found on the outer membrane to help identify other cells.
Paleontology is the study of the history of life on earth as based on fossils.
Answer:
Generally, the Earth is divided into spheres which include the "lithosphere" (land), "hydrosphere" (water), "biosphere" (living things), and "atmosphere" (air). The earth is divided into three layers based on chemical composition and these are the core, mantle and crust. In addition, the earth is also divided into physical properties which include lithosphere, athenosphere, mesosphere, outer core and inner core. Based on the given details, we can conclude that the atmosphere cannot be part of the lithosphere but instead, it is classified in a separate layer. The lithosphere only consists the outermost, rigid part of the Earth, which are the crust and the mantle. Hope this answer helps
Explanation: