Family traits

Definition of Genetics

Genetics is the scientific study of heredity and variation in living things. The transfer of materials which lead to heredity and variation occurs during reproduction in living things.

Heredity is a branch of genetics which studies how children or offspring take after their parents.

FAMILY TRAITS can be defined as transmittable characteristics which are passed from parents to offspring or children or progeny from one generation to another through reproduction. You may have your hair color as your mother or your eye color as your father.

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We all have inherited traits that we share in common with others. Families share many traits in common because parents pass down inherited traits to their children. Yet, every person has a combination of traits that is unique to them. However, the modern science of genetics which seeks to understand the process of inheritance only began with the work of Gregor Mendel in the mid-19th century. Although he did not know the physical basis for heredity, Mendel observed that organisms inherit traits via discrete units of inheritance which are now genes. Gregor Mendel is the father of Genetics because his work on genetics formed the foundation for quantitative and scientific study of genetics.

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EXAMPLES OF FAMILY TRAITS

1. Colour of skin ( Complexion )
2. Height ( Tallness or Shortness )
3. Colour of eyes
4. Colour of hair
5. Intelligence
6. Shape of nose
7. Blood group
8. Albinism

DNA Strands

Nucleic acids are complex molecules produced by living cells and are essential to all living organisms. These acids govern the body’s development and specific characteristics by providing hereditary information and triggering the production of proteins within the body. This computer-generated model shows two strands of deoxyribonucleic acid (DNA) and the double-helical structure typical of this class of nucleic acids.

It should be noted that the transmission of traits from parents to offspring or children (heredity) only cannot determine the manifestation of the traits. The environment plays its own part as heredity is the nature while the environment is the nurture.

This karyotype of a human male shows the 23 pairs of chromosomes that are typically present in human cells. The chromosome pairs labeled 1 through 22 are called autosomes, and have a similar appearance in males and females. The 23rd pair, shown on the bottom right, represents the sex chromosomes. Females have two identical-looking sex chromosomes that are both labeled X, whereas males have a single X chromosome and a smaller chromosome labeled Y.

MEANING OF DOMINANT AND RECESSIVE TRAITS

A dominant trait can be defined as a trait that is expressed in an offspring when two individuals with contracting traits or characteristics are crossed. Dominant traits are controlled by dominant genes.(RR, TT)

A recessive trait can be defined as the traits from parents which do not produce any effects in the presence of dominant traits. Recessive traits are controlled by recessive genes. (rr, tt)

Both parents have to be carriers of a recessive trait in order for a child to express that trait. If both parents are carriers, there is a 25% chance with each child to show the recessive trait.

The genes are the basic unit of heredity. They determine the nature of inherited characteristics or traits.

IMPORTANCE OF FAMILY TRAITS

The importance of family traits cannot be over-emphasized. It is possible to predict traits to be expected in the offspring before marriage is conducted between two individuals. Family traits can be used to:

1. Determine the intelligence of individuals
2. Determine or detect certain diseases that run in the family. An example is sickle cell anemia
3. Determine in particular who does a child resemble in the family
4. Determine the blood group of an individual which could be A, B, AB or O.
5. Trace the family genealogy

The family genealogy or family tree or pedigrees are lines of generation of parents and offspring which trace the descendants of a man and his wife. A man with more than one wife will have one family tree for each of his wife

EVALUATION

1. State five importance of family traits
2. Explain family genealogy
3. Define the word family traits
4. List five family traits
5. The scientific study of heredity and variation is called ……………..
6. Traits are also called ……………
7. ………….. is also referred to as progeny
8. Who is the father of genetics?