Part A:
Bacteria vs. Virus
Bacteria are known to have distinct structural characteristics and evolutionary lineage. Rods (bacilli) and cocci (spheres) are common bacterial shapes. In addition, bacteria may be comma-shaped (vibrio), spiral (spirillum and spirochetes), or filamentous; they may form buds and stalks; or they may have no characteristic shape (pleomorphic). Some cells remain together after division to form pairs, chains, and clusters of various sizes and shapes. Frequently observed bacterial cell structures include a cell wall, plasma membrane, cytoplasm, nucleoid, fimbriae, inclusions, capsule, ribosomes, and flagella. Bacteria reproduce asexually by the process of binary fission. On the other hand, a virus reproduces by harnessing the host cell machinery. Viruses are non-living microorganisms. They are unable to reproduce and lack many structural components that determine they are non-living such as the cells. Viruses are very small and are 20-400nm in size. They have varied shape and chemical composition, and their most fundamental level is composed simply of protein, DNA or RNA genome, capsid, and viral envelope. The viral envelope consists of proteins that help it adhere and penetrate a host cell. However a bacterial cell
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In other words, 23 homologous pairs from each parent that lead to 46 chromosomes. Prior to mitosis or meiosis DNA replication occurs. In both Meiosis and mitosis the nuclear membrane breaks down as the DNA organises into chromosomes. In meiosis crossing over or synapse occurs resulting in the mixing of the genetic information between the chromosome pairs. The paired chromosomes align at the central plate of the cell leading to 4 cells with one set of chromosomes as paired chromatids. Mitosis results in a single division of the chromosomes resulting in no net change in chromosomes leading to two identical
...indole, it is motile, there is no urease present and there is no coagulase activity. By deduction and logical reasoning Unknown 10a was determined to be Escherichia coli.
Phenotypic methods of classifying microorganisms describe the diversity of bacterial species by naming and grouping organisms based on similarities. The differences between Bacteria, Archaea and Eukaryotes are basic. Bacteria can function and reproduce as single cells but often combine into multicellular colonies. Bacteria are also surrounded by a cell wall. Archaea differ from bacteria in their genetics and biochemistry. Their cell membranes are made with different material than bacteria. Just like bacteria, archaea are also single cell and are surrounded by a cell wall. Eukaryotes, unlike bacteria and archaea, contain a nucleus. And like bacteria and archaea, eukaryotes have a cell wall. The Gram stain is a system used to characterize bacteria based on the structural characteristics of their cell walls. A Gram-positive cell will stain purple if cell walls are thick and a Gram-negative cell wall appears pink. Most bacteria can be classified as belonging to one of four groups (Gram-positive cocci, Gram-positive bacilli, Gram-negative cocci, and Gram-negative bacilli) (Phenotypic analysis. (n.d.).
Viruses are the simplest and tiniest of microbes, and are made up of proteins, nucleic acid, and lipids. The nucleic acids contain the genetic code that helps them grow and reproduce, but only once they find their way into a living organism. Viruses themselves are not considered living organisms because they don’t have cells, they don’t metabolize nutrients, produce and excrete wastes, and they can’t move around on their own. The remains of the nucleic acid then forms a covering, called the capsid. Once the capsid gets removed, viruses use the building materials of th...
Each cell contains the same genetic code as the parent cell, it is able to do this because it has copied it’s own chromosomes prior to cell death. division. The. Meiosis consists of two divisions whilst mitosis is followed. in one division; both these processes involve the stages of interphase, prophase, metaphase, anaphase, and telophase.
Bacteria, viruses, and prions all have different types of structures. However, bacteria and viruses are more alike in the aspect of nucleic acid. Bacteria come in numerous shapes, but most bacteria are in the shape of a sphere (cocci). Their other shapes, or structure, are rods (bacilli), spirals (spirilla), and if they’re rigid then they are called spirochetes. Bacteria will normally come in a single cell form; however they can come in more than one, and they can also form chains. A bacterium doesn’t contain a nucleus because they are prokaryotes. On the other hand, it does have nucleic acid. The nucleic acid lies in the nucleoid plasmids. Bacterium doesn’t have membrane-bounded organelles and an outer cell wall. The outer cell wall is strengthened by peptidoglycan, which protects the bacteria from collapsing or bursting. Some bacteria have the means to move. The reason they’re able to move is because they have flagella. Flagellum is a long slender tail-like structure. Virus’s structure is less complex than the structure of bacterium. All viruses are composed of two parts: the outer capsid, and the inner core. The outer capsid is made of protein subunits, and the inner core contains the DNA. Also with virus structures comes the envelope. The envelope is part of the host’s plasma membrane...
The process of mitosis can take place in either a haploid (23 chromosomes) or a diploid (46 chromosomes) cell. Before a cell can be ready for a mitotic division it must primarily undergo its interphase stage. Following the interphase stage several other stages come into play. These stages are prophase, prometaphase, metaphase, anaphase, and telophase. During each specific stage certain sequences of events take place that assist to the completion of the division.
... of bacterial dna buy viruses. When they invade the bcacterial cell they make use of the bacterial protein machinery to produce virions. During process packaging where genetic material is packed into the newly formed virus, bits of bact dna are also included. The new virions carry bact dna into the next cell they infect
A chromosome is made up of two identical structures called chromatids. The process of nuclear division is called interphase; each DNA molecule in a nucleus makes an identical copy of itself. Each copy is contained in the chromatid and a characteristic narrow region called the centromere holds the two chromatids together. The centromere can be found anywhere along a chromosome but the position is the characteristic for a particular chromosome. Each Chromatid contains one DNA molecule. DNA is the molecule of inheritance and is made up of a series of genes. The fact that the two DNA molecules in the sister chromatids, and hence their genes, are identical is the key to precise nuclear division.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
The differences between the phases of mitosis and meiosis are that in mitosis, it has 1 cell division, duplicates the DNA, occurs in somatic cells, and no crossing over happens. In meiosis, it has 2 cell divisions, reduces the DNA, occurs in gametes or sperm and egg cells, while crossing over happens. They are both similar in which they both create daughter cells, headed by at least one round of DNA replication, and have similar stages for cell division.
Prescott, Harley & Klein (1990) describe bacteria as prokaryotic cells (cells that lack a true membrane enclosed nucleus). Bacteria are both small and simple in structure; they usually are between o.5 and 5cmm yet they have many characteristic shapes and sizes. Some bacteria are circular or oval shaped, they are known as cocci bacteria. Other bacteria are rod-shaped, they are known as bacilli bacteria, and some bacteria are spiral and coil-shaped and it is know as spirilla bacteria.
Bacteria are single celled microbes. Bacteria reproduce by binary fission. In this process, the bacterium, which is a single cell, divides into two identical daughter cells. Binary
In Meiosis 1, chromosomes in a diploid cell resegregate, producing four haploid daughter cells. It is this step in Meiosis that generates genetic diversity.Meiosis 2 is similar to mitosis. However, there is no "S" phase. The chromatids of each chromosome are no longer identical because of recombination. Meiosis II separates the chromatids producing two daughter cells each with 23 chromosomes (haploid), and each chromosome has only one chromatid.
Once the sperm fuses with the ovum both chromosomes will pair up and begin the first stages of cell division.
There are certain things that must happen first before the cell can actually split. There is a six step process required during Mitosis. The first five steps of mitosis are called prophase, prometaphase, metaphase, anaphase, and telophase. This is where all the training and preparation is done for cell division. The sixth step is Cytokinesis, and that is when the cell literally splits into two. Like I said, there are certain things in order to happen before it can enter the M phase. first, it must meet the requirements of the certain size and environment. Since in the S phase the cell duplicated it’s amount of chromosomes it be represented as 2N, where N equals the number of chromosomes in the cell. Cells about to enter M phase, which have passed through S phase and replicated their DNA, have 4N chromosomes. Because of this they are now allowed to enter within the M phase to prophase. Here is where the cell thickens up its chromosomes and begin to sprout microtubules from clone centrosomes. Microtubules tub-like are protein filaments and where the chromosomes migrate but are still within the nuclear envelope in the nucleus. There are centromeres, that are inside the chromosomes and during the later process of this phase, specialized microtubules called kinetochores, assemble on the centromere then later attach to these sites. They act like magnets and go