Rather, each myelin sheath insulates the axon over a single long section and, in general, each axon comprises multiple long myelinated sections separated from each other by short myelin sheath-gaps called nodes of Ranvier. ... In the CNS, axons carry electrical signals from one nerve cell body to another.
The correct answer is option C
The original source of energy is the sun while most of the energy in the organisms is used in the form of energy. The energy from the sun is used by the green plants to make food by the process of photosynthesis and this food is used by the human beings and animals. The energy in animals and human is in the form of ATP.
The correct answer is option D
Both are made up of the same nucleotide, but in a different sequence
DNA is made up of same set of nucleotide only the sequence is different which generates different set of amino acids forming the proteins of different types.Proteins are the building blocks of DNA which are responsible for different characteristics of an individual.
Answer: True
Explanation:
<u>A cell membrane consists of a lipid bilayer made of polar phosphate head and a nonpolar lipid tail.</u> It is semipermeable and regulates the transport of materials through it. For this,<u> it is selectively permeable</u> and since it is made of lipids, hydrophobic and small polar molecules can diffuse easily through it by simple diffusion and down their concentration gradient. However, polar molecules, large molecules (such as glucose) and ions are not able to pass through it because they are repelled.
To accomplish the transport of these molecules that can not diffuse, proteins embebbed in the membrane function as carriers that enable the transport of polar molecules, large molecules and ions by passive (through facilitated diffusion, down its concentration gradient) or active transport (movement against its concentration gradient).
