Back to: Jss3 Basic Science

Introduction

Have you noticed that kids often look like their parents and that siblings often look like each other? This is because there are some traits that run in families and get passed down from parents to children. These are what people call “family traits.” You will learn about family traits in this topic.

Meaning of Genetics

Genetics is the scientific study of how traits are passed down and how they change in living things. During reproduction, living things pass on the parts that lead to heredity and variations.

Heredity

Heredity is also referred to as biological inheritance, it is the passing on of traits or characters from parents to their offspring, i.e., a part of genetics that looks at how children are like their parents.

Variation

Biology defines variation as any difference between cells, individuals, or populations of any species that is brought on by either genetic differences (genotypic variation) or the influence of environmental conditions on the expression of the genetic potentials 

Family Traits

Family traits are traits that can be passed down from one generation to the next. These traits are passed from parents to children or grandchildren through reproduction. You might have your mother’s hair colour or your father’s eye colour.

We all have traits that we share with other people that we got from our parents. Families have a lot in common because parents give their children the traits they have. Still, each person has a unique mix of traits that make them who they are. But modern genetics, which tries to figure out how traits are passed down, didn’t start until Gregor Mendel’s work in the middle of the 19th century. Mendel didn’t know how heredity worked on a physical level, but he did notice that organisms pass on traits through discrete units of inheritance, which we now call genes. Gregor Mendel is known as the “Father of Genetics” because his work on genetics made it possible to study genetics in a scientific and quantitative way.

Examples of Family Traits

• Colour of skin ( Complexion )
• Height ( Tallness or Shortness )  
• Hair Color  
• Intelligence
• The shape of the nose
• Blood type
• Albinism

Dominant And Recessive Traits 

When a trait keeps showing up in each generation, it is said to be dominant. When a trait is present in a person but doesn’t show up physically, it is said to be recessive.

Dominant Traits

If a tall man with the dominant trait of being tall, TT, marries a tall woman with the recessive trait of being short, Tt, and they have four children, all of them will be tall. This means that the gene for being tall is stronger than the gene for being short.

This is demonstrated below:

∴ they are all tall.

Genotypic Ratio   =  2:2.

Phenotypic Ratio  = 4:0.

Recessive Traits: 

If a tall man, TT, marries a short woman, tt, they might not have any short children, but their children who have recessive traits might have short children in the next generation.

This is illustrated below:

Genotypic Ratio = 4:0.

Phenotypic Ratio = 4:0.

However, in the second generation, short children can be produced. 

This is illustrated below:

Genotypic Ratio = 1:2:1.

Phenotypic Ratio = 3:1.

Importance Of Family Traits .

Family traits can be used to:

1. Determine Intelligence:

The ability to think critically is a valuable inheritance that should be encouraged. The educational background of one’s parents is a useful indicator of the kind of work that would be most satisfying to them.

2. Determine or Detect Diseases:

Sadly, there is a genetic component to several disorders. Conditions including hypertension, myopia, sickle cell anaemia, asthma, and so on are passed on from parents to children.

If a doctor is familiar with a family’s medical history, he can more easily diagnose and treat conditions like asthma in kids.

The disorder known as sickle cell anaemia is yet another illustration. Both parents need to convey the genetic defect to their child for them to be afflicted, but if only one parent does, the child will only get the sickle cell trait. Partners carrying the genetic disorder are counselled against having children.

3. Determine a Child’s Relationship:

When a child looks like one of the parents, that helps show that he is that parent’s child. This is important in paternity cases, especially when a man isn’t sure if he’s the real father.

4. Determines Blood Group:

A person’s blood group, which could be A, B, AB, or O, is based on their family.

5. Helps trace family genealogy:

A family tree, also called a genealogy, is a way to show how different generations of a family are linked over time. It helps individuals know where they came from, or learn about hereditary diseases in their family

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How to make a family tree:

1. Gather information about your family. Usually, it’s best to talk to an older family member who can help you name people from older generations. Talk with as many people as you can, including your parents. You might want to find documents, pictures, newspaper articles, photos, and other things to add to your family tree to make it more interesting to look at.

2. Make a list of all the family members you want to include, and keep in mind that you can always add more. You can start with your great-grandparents.

3. Make a “leaf” for each family member and include their names, dates, photos, and any other information you want.