Heredity is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. The study of heredity in biology is genetics.
A trait may be any single feature or quantifiable measurement of an organism.
However, the most useful traits for genetic analysis are present in different forms in different individuals.
A visible trait is the final product of many molecular and biochemical processes.
In most cases, information starts with DNA traveling to RNA and finally to protein (ultimately affecting organism structure and function).
This information flow may also be followed through the cell as it travels from the DNA in the nucleus, to the Cytoplasm, to the Ribosomes and the Endoplasmic Reticulum, and finally to the Golgi Apparatus, which may package the final products for export outside the cell.
Cell products are released into the tissue, and organs of an organism, to finally affect the physiology in a way that produces a trait.
5 Heredity Examples!
A dimple (also known as a gelasin) is a small natural indentation in the flesh on a part of the human body, most notably in the cheek or on the chin.
An eyelid is a thin fold of skin that covers and protects the human eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. The human eyelid features a row of eyelashes along the eyelid margin, which serve to heighten the protection of the eye from dust and foreign debris, as well as from perspiration. “Palpebral” (and “blepharal”) means relating to the eyelids. Its key function is to regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist. They keep the eyes from drying out when asleep. Moreover, the blink reflex protects the eye from foreign bodies.
The human earlobe (lobulus auriculae) is composed of tough areolar and adiposeconnective tissues, lacking the firmness and elasticity of the rest of the auricle (the external structure of the ear). In some cases the lower lobe is connected to the side of the face. Since the earlobe does not contain cartilage it has a large blood supply and may help to warm the ears and maintain balance. However, earlobes are not generally considered to have any major biological function. The earlobe contains many nerve endings, and for some people is an erogenous zone.
The zoologist Desmond Morris in his book The Naked Ape (1967) conjectured that the lobes developed as an additional erogenous zone to facilitate the extended sexuality necessary in the evolution of human monogamous pair bonding.
Tongue rolling is the ability to roll the lateral edges of the tongue upwards into a tube. The tongue’s intrinsic muscles allow some people to form their tongues into specific shapes. Popular belief holds that variation in this ability is the result of genetic inheritance. Rolling the tongue into a tube shape is often described as a dominant trait with simple Mendelian inheritance, and it is commonly referenced in introductory and is genetic biology courses.
A prominent nose is regarded as abnormal if it is larger than average, but even within different cultures this is very subjective. Larger prevalence of the prominent nose in a total population is seen in the Mediterranean basin and in the Middle East.
Patients look at their noses through a prism of internal reflection, which may also be the outlet for a psychological load they carry inside. When patients are photographed in profile and asked to draw the desired change in the nasal profile, they will frequently draw the nose unreasonably small. The surgeon must balance the patient’s dreams and desires and the existent anatomic predispositions with his knowledge of predictable surgical techniques and healing processes to obtain favorable yet well-camouflaged results.
Although beauty can be interpreted variably, certain geometric criteria and accuracy of proportions must be met. Goode introduced a simple formula that delineates the approximate relationship between tip projection and nasal length ( Fig. 15.1 ). The Goode ratio is an expression of proportion in measurement between a line drawn from the alar crease to the nasal tip and from the nasal tip to the nasion. In the aesthetically-pleasing Caucasian nose BC should equal 0.55 to 0.60 of AB. If it is more than that, the nose is overprojected; if it is less, the nose is underprojected. Adherence to this ratio prevents underprojection or overprojection with rhinoplasty. If there is a preoperatively unrecognized deviation from this ratio that persists after the surgery, the final result will be substandard.