Traits: Inherited vs. Acquired

Traits are something that is passed on. Although many of these are inherited, or passed down from generation to generation, others are acquired through a large variety of activities that are “picked up”, or gained through different experiences.

Inherited traits are not passed solely from a single parent, but instead are passed on from both parents in sexually reproducing organisms. Some examples include the color, length, and type of hair you have, the color and the shape of eyes you have, the general body shape you have, etc. You don’t control which genes you receive because your parents each contribute to your genotype, or genes, that you have. For example, if both your parents have brown eyes, you are very likely to have brown eyes too. However, you are not guaranteed to receive the traits shown in your parent’s phenotypes, or appearance. Alleles can be dominant or recessive. If a dominant allele is present in a genotype, it will show for sure in your phenotype. Recessive traits are overpowered by dominant alleles, but when both alleles inherited are recessive, both the allele received from your mother and the allele received from your father, the recessive trait will be shown in the phenotype of the organism.

Acquired traits are traits that are picked up or developed over a period of time through forming habits. This can include knowledge, skills, ideas, memories, behaviors, and personality traits. These traits are not passed genetically from parent to child, or generation to generation. You have more control over these traits that you acquire because you can control them, unlike your genotypes.

Acquired traits can be influenced by many different factors. Inherited traits will always be present and are passed down from generation to generation. Both of these types of traits combine together in order to make you who you are, a unique individual.

Gregor Johann Mendel and His Discoveries

Gregor Johann Mendel of 1822-1884 was an advanced scientist who discovered and researched the inheritance of traits from generation to generation. Through his studies and research of pea plants, he was able to observe that when two pea plants mate to produce offspring, they do not always result in the exact same phenotypes as their “parents”. Gregor Mendel was known as the “father of modern genetics” and made the discovery as a monk while tending to his monastery garden (biography.com). Before Mendel’s experiments, the people of the mid-1800’s had accepted the belief that offspring were just a blended up version of their parents, inheriting all traits from both the mother and the father, similar to the mixing of paint, blue mixed with yellow makes green.

Through Mendel’s experiments, he discovered two laws, including the Law of Segregation, and the Law of Independent Assortment. As he published his results, the people misunderstood them, and were very confused by them, believing that the research he had conducted had only proved what they already knew, that the two mixed up and created a duplicate of both parents in one. The people did not accept Mendel’s findings and Mendel himself often struggled to accept them as the truth behind the science of the passing on of traits and genetics. These findings and important observations were not recognized to be true for years after scientist Gregor Mendel had passed, however, these findings have become known as the base of biology studies today and are very well known throughout the scientific field.

Malfunctioning Meiosis and Genetic Disorders

Meiosis is the process of making sex cells, which are haploid (only contain 1 of each type of chromosome in each cell, 23 of 46 in humans). These are known as sperm cells in males, and egg cells in females. Although this is a process that occurs often, 24/7 in males, and once approximately every 28 days in females, mistakes do occur during the process in both genders. If the sex cell that is not “normal” is the one to fertilize the egg, or is fertilized by the sperm cell, the child could be born with a condition, or a chromosome disorder, depending upon the mistake that was made during the process.

Cri-du-chat is French for “cry of the cat”. It is called this due to the cry that children have when they have this disorder. This disorder causes the deletion on the short arm of Chromosome number 5, causing many genetics to “disappear”, or be lacking during the ‘assembly’ of the organism, in this case, the child. This syndrome is one of the most common chromosome deletion genetic disorders and affects between 1 in 20,000 to 1 in 50,000 children. Some symptoms of the Cri-du-chat Syndrome can include wide-set eyes, mental retardation, and a small jaw, downward slant in the eyes, a small head, and skin tags in front of the ear, slow growth, partial webbing of fingers or toes, high-pitched cat cry, and more. There are currently no known treatments or cures to this disorder.

 

 

Down syndrome is a genetic disorder where extra genetic material causes a large variety of problems for the holder. It is a condition in which there is extra genetic material in the body and delays the way the child develops physically and mentally (Kids Health). Although it is not preventable, there are treatments available to help children with this condition. Chromosome number 21 is the extra chromosome the baby inherits to get this disease, causing a change in physical appearance. Children with Down syndrome often have flattened facial features, small head, short neck, protruding tongue, and unusual shaped ears. Also, they may have poor muscle tone, short hands and short fingers, a single crease in the palm, and excessive flexibility (Mayo Clinic). Down syndrome is usually not inherited; however it could be passed down. Most of the time, this disorder is caused solely by the abnormal cell division during Meiosis and results in an extra chromosome 21.

As you can see, Meiosis is an essential process for proper development and what is considered normal and not. Scientists are always looking for new ways to cure and prevent these, and many other genetic orders found within different organisms.