Answer:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
Explanation:
Answer:
b. axons
Explanation:
The Peripheral Nervous System consists of nerves and ganglia. Nerves are nothing more than bundles of parallelly arranged nerve fibers surrounded by connective tissue. Each of these fibers is formed by an axon and the sheaths surrounding it. The ganglia, in turn, are accumulations of neurons, which usually form spherical structures, are located outside the central nervous system and are also linked by axons bridges.
Answer:the nucleus
Explanation:mRNA is synthesized in the nucleus using the nucleotide sequence of DNA as a template. This process requires nucleotide triphosphates as substrates and is catalyzed by the enzyme RNA polymerase II. The process of making mRNA from DNA is called transcription, and it occurs in the nucleus
The answer to your question is flowering plants are the most recently evolved of the major groups of plants, arising only about 130 million years ago. Despite their geological youthfulness, angiosperms are the dominant plants of the world today: about 80% of all living plant species are flowering plants. Furthermore, they occupy a greater variety of habitats than any other group of plants. The ancestors of flowering plants are the gymnosperms , which are the other major group of plants that produce seeds. The gymnosperms, however, produce their seeds on the surface of leaf-like structures, which makes the seeds vulnerable to mechanical damage when winds whip the branches back and forth, and to drying out. Most importantly, conifer seeds are vulnerable to insects and other animals, which view seeds as nutritious, energy packed treats. In angiosperms, the margins of the seed-bearing leaves have become inrolled and fused, so the seeds are no longer exposed but are more safely tucked inside the newly evolved "vessel," which is the ovary.
The other major advance of the angiosperms over the gymnosperms was the evolution of the flower, which is the structure responsible for sexual reproduction in these plants. The function of sexual reproduction is to bring together genetic material from two individuals of differing ancestry, so that the offspring will have a new genetic makeup.
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