Essay on Characteristics of Living Organisms

Life has various characteristics or traits that are always shared by the living organisms. They include:

Cellular organization.

Living organisms are composed of cells. The cells are the basic or fundamental unit of any given life. Some organisms are unicellular while there are those, which are multicellular.

Homeostasis

It takes place when living things try maintaining or regulating an internal environment that is very stable. It occurs even though the external environment is usually faced with changes in temperature levels (Ejayes, 2018). The disruption of homeostasis may spike a fever, which indicates a threat to life.

Metabolism

It refers to the sum of the entire chemical reactions, instrumental in the provision of living organisms with the necessary energy. The chemical reactions differ in their functions and form but aids in the promotion of processes like chemical digestion, protein synthesis, energy transformation and cell division.

Responsiveness to Stimuli

It refers to the process through which living things react to the external environment.  Homeostasis maintenance is facilitated when all living organisms have developed a mechanism of responding to the immediate external environment.  It may be through shivering, sweating or even a sunflower tilting in the sun direction.

Heredity

The living organisms can pass their genetic information to the off springs. The inherited genes may be informed of physical or biochemical traits like eye color. All living things store their information concerning heredity in the states of nucleic acid molecules, which includes the RNA or DNA.

Reproduction

It is the continuation of life. All living things are capable of reproducing. The multicellular organisms have sexual reproduction while the unicellular organisms such as bacteria undertake asexual reproduction.

Growth and development

All things develop and grow depending on their particular genes formation. The genes help in the provision useful instructions, which direct the growth, and development of cells. It ensures the off springs have the same traits as the parents.

Cell anatomy and physiology

A cell is a basic unit of all living organisms. It is composed of three main parts, which include the nucleus, plasma membrane, and cytoplasm.

The plasma membrane

It is the permeable structure or membrane, which covers the cell, also helps in the protection of the cell from the external environment, and controls what leaves and enters the cell. The substances are transported across the plasma membrane through the various processes such as osmosis, diffusion, active transport, pinocytosis, phagocytosis, and Exocytosis.

The Cytoplasm

It is the gel-like structures, which are found inside any given cell. The cytoplasm is composed of the intracellular fluid or cytosol, the organelles and cell inclusions. The cytosol is composed of mainly water where different molecules undergo dissolution or suspension. The molecules include fats, proteins, carbohydrates and various metal ions. Many cell reactions take place in the cytosol.

Cell inclusions

They are large particles of glycogen, melanin and fat, which are produced by the given cell. The cell inclusions are always large and can be viewed by a light microscope.

Organelles

They are the tiny organs of the cell. The organs have characteristic appearances and perform specific jobs in any given cell. The primary organelles include the ribosomes, mitochondrion, lysosomes, endoplasmic reticulum and Golgi complex. The ribosomes aid in the making of proteins by joining the amino acids (Antipuesto, 2011). The mitochondrion is used in the making of energy through the process of burning various food molecules such as glucose. The Golgi apparatus help in the modification and sorting of fats and proteins. The lysosomes contain digestive enzymes, which facilitate the breakdown of bacteria and other different substances. Lysosomes also help in the digestion of damaged or worn-out organelles.

The Nucleus

It controls the activities and development of the cell. The nucleus contains nucleoli whips in making new ribosomes.

Cell Respiration

It is the biochemical process which facilitates the release of energy from the various chemical bonds of any given food molecule and helps in the provision of energy to be used in the essential life processes. Cell respiration can be either aerobic which occurs in the presence of oxygen or anaerobic respiration. The energy is combined ADP and the ions from phosphate to form ATP molecules. The entire process also requires oxygen gas, which serves as an electron acceptor. The cellular respiration results in the production of carbon dioxide as a metabolic waste. The entire cell respiration entails four subdivisions. They include glycolysis, Krebs cycle, the electronic transport mechanism and chemiosmosis.

Photosynthesis

Refers to the mechanism by which some bacteria and plants utilize the sunlight energy to aid the production of glucose from water and carbon dioxide. The glucose is convertible into pyruvate that releases ATP.The process of converting energy from sunlight into chemical energy is aided by the actions of the chlorophyll. An electron always gains energy whenever there is the absorption of light energy by the chlorophyll. The photo activation of chlorophyll enhances the splitting of water molecules, energy transfer to the ATP.It involves the redox and the condensation chemical reactions.Photosythe3sis occurs in two distinct stages, which include light dependent and light independent reactions.

Cell reproduction

Refers to the mechanism by which various cells divide and form new cells. Each time there is cell division, a copy of chromosomes is made which are coiled tightly in the strands of the DNA.A chromosome is composed of two chromatids .The chromatids have a centromere, which attaches to the spindle fibers during the process of mitosis.

Mendel's Law

There are three laws are which always applied to gene formation and heredity.

Law of Segregation

It depicts that during formation of gamete, separation of allele’s takes place hence each gamete only contains one given allele of any gene.

Law of independent assortment

States that the segregation of alleles for a given gene takes place autonomously or independent of other genes of the cell.

Law of Dominance

It states that the alleles, which are recessive, will be masked by the allele, which is dominant in that given gene.

DNA structure and function

The DNA is a simple molecule, which plays different roles in the cell. It acts as a very stable genetic information repository. It is also a source of genetic information, which is helpful in the protein production. It consists of nucleotides, which entails deoxyribose (sugar), a group of phosphate and nitrogenous bases: Thymine, Adenine, cytosine, and Guanine. Nucleotides vary depending only on the specific nitrogenous base they possess. The Ribonucleic acid is another form of nucleic acid but it consists of ribose as the sugar and has uracil as a nitrogenous base. It exists double-stranded molecule.

Cancer and gene control

Some specific genes help in the control of when the old cells die and the formation of new ones. They also help in the repair of the damaged DNA.various changes in the given genes leads to the increased danger of the development of cancer (Macmillan cancer support, 2015). There exist two forms of mutations (changes), namely the inherited and acquired mutation. Cancer is mostly caused by the accumulation of acquired mutation in the life of a person and is referred to as sporadic cancer.

References

Macmillan cancer support. (2015). Cancer and genes. Retrieved from

https://www.macmillan.org.uk/information-and-support/diagnosing/causes-and-risk-factors/family-history/cancer-and-genes.html

Antipuesto.D.J. (2011). Anatomy and Physiology: Cells. Retrieved from

http://nursingcrib.com/anatomy-and-physiology/anatomy-and-physiology-cells/

Ejayes. (2018). 7 Properties of Life. Retrieved from

https://quizlet.com/2396261/7-properties-of-life-flash-cards/