Answer:
Answer No 1:
The earliest evidence for the occurrence of viruses was the discovery of an infectious agent in the sap of a tobacco plant. Experiments were set with different filters from which bacteria could pass but viruses being even smaller than bacteria could not pass.
Viruses were difficult to study because they are very small and couldn't be seen even under a microscope.
Answer No 2:
Wendell Stanley made his studies on the tobacco mosaic virus (TMV). Wendell Stanley developed techniques and crystallized this virus. At that time, it was known that even a very simple cell does not undergo crytallization. Hence, Wendell Stanley got to known that this structure is some infectious agent which has the ability of crystallization.
Answer No 3:
The four forms of viral genomes are:
- double-stranded DNA
- single-stranded DNA
- double-stranded RNA
- single-stranded RNA.
Answer No 4:
The capsid can be described as proteins which make up a shell to enclose the genome of a virus. Capsomeres can be described as the protein sub-units from which a capsid is made. The shapes of a capsid can be characterized into
- rod-shaped: helical viruses, or inside spherical viruses
.
- icosohedral: icosohedral viruses or the heads of bacteriophages.
Answer No 5:
The components of a viral envelope involve phospholipids and membrane proteins and proteins and glycoproteins. The phospholipids and membrane proteins are derived from the host cell. The proteins and glycoproteins are of the viral origin.
Bacteria have been the very first organisms to live on Earth
Answer:
An oxygen atom is what is found on the periodic table. The Oxygen atom is made of 8 proton, 8 electrons and generally 8 neutrons.The oxygen molecule is made of two oxygen atoms that have formed a double bond with each other and share valence electrons.
Explanation:
The correct answer is known as a "motor neuron".
A motor neuron or also known as a motoneuron is described as <span> a neuron whose </span>cell body<span> is </span>placed inside the<span> motor cortex, brainstem or the spinal </span>cord<span>, and whose axon </span>initiatives<span> to the spinal cord </span><span>or </span>the exterior<span> of the spinal </span>cord<span> to </span>immediately<span> or </span>not directly manage<span> effector organs, </span>specifically muscle mass<span> and glands. </span>
