Cells: Cells can be called a basic building block of the body or living things. Cells can be divided into two parts. One is PROKARYOTES and one is EUKARYOTES. A EUKARYOTIC cell has a nucleus and membrane-bound organelles, whereas the prokaryote does not have that organ. Most of the plants and animals are eukaryotes. But many microbes like bacteria consist of a single cell. As an example, the Human body has 10 to 100 trillion cells in its body. Again according to Carla Easter “cells are like own little kind of nanoparticles and they have their own activities, and they form tissues by joining with each other.
Cell Cycle: The cell cycle can be defined also as the lifecycle of a cell, which means how it’s growing and spreading and forming tissues, etc. A cell spends its major time in this interphase and there it grows, replicates, and divides itself. Then it comes out from the stage of interphase and goes into the mitosis cycle, where it completes its division. Different stages of the cell cycle are known as G1, S, G2, M, etc. In the G1 stage, the cell gets ready to divide and for this, they move into 5 phases where they copy the DNA. The next stage is DNA synthesis here they copy the genetic material from the copied genes. Then in the G2 phase, it gets condensed and organizes the genetic material. Then finally go to the M phase or mitosis phase.
Function: As the cells are called building blocks for the human body, it creates the structure of the body, extracts nutrients from foods, and converts them into energy. The cell has one more very important function, it contains the hereditary material of the body and can replicate them.
Virus: A virus can be called a collection of GENETIC CODES. The virus can’t replicate itself alone. The virus uses the host cell components to make a copy of that host cell. There are viruses everywhere on the earth. Viruses can’t be killed by antibiotics, only antiviral medicines or vaccines can reduce their syndrome. Examples are COVID-19, AIDS virus. Viruses are submicroscopic means they are not visible under a microscope. Viruses can have two or three parts. First nucleic acid can be RNA or DNA, and for DNA it is DOUBLE-STRANDED and for RNA it’s SINGLE STRANDED. Then the nucleic acids are bounded by the protein coat called CAPSID. Another interesting fact is Viruses can live and replicate within a living cell.
DNA: DNA is a kind of molecule that can be said which carry out genetic instructions through living things. As DNA is Double-stranded, it is also called DOUBLE-HELIX. The backbone of each strand is made up of sugar and phosphate groups, and with sugar, there are four bases ADENINE, THYMINE, GUANINE, CYTOSINE. ADENINE makes a bond with THYMINE, and CYTOSINE makes a bond with GUANINE. DNA is also called a CENTRAL INFORMATION STORAGE SYSTEM.
RNA: RNA is also a kind of molecule like DNA. DNA is Double-stranded but RNA is single-stranded. The cell uses RNA for different tasks. mRNA, tRNA these are the types of RNA. Messenger RNA transfers information from the genome to protein.
Function: The function of a virus is to deliver the genome to the host cell to copy or allow the expression of the host cell. Small viruses can be crystallized and viruses are unable to produce energy.
Important types of viruses: EPSTEIN-BARR VIRUS, ADENOVIRUSES, COXSACKIEVIRUS, MEGAVIRUS, MARBURGVIRUS, INFLUENZA A VIRUS, NIPAH VIRUS, HEPATITIS C VIRUS, HEPATITIS B VIRUS, ESCHERICHIA VIRUS T4, MONKEYPOX VIRUS, DENGUE VIRUS, HIV-1, RABIES VIRUS, BK VIRUS, NORWALK VIRUS, HERPES SIMPLEX VIRUS, HUMAN CORONAVIRUS 229E, MUMPS VIRUS, HEPATITIS A VIRUS, etc.