Have you ever heard that you resemble your parents or might be with your siblings or cousins? Or are you confused about the concept of genes ( how genes come from)? How do you resemble your parents or anyone else? Now all your confusion or concept regarding genes or hereditary character might be clear.
Gene and allele are crucial for rudimentary genetics. All living organisms have genes and gene submit throughout the body. Basically, genes are a set of order which decides what living being is like? It’s appearance.
This content helps you to understand very basic concept of genes and alleles, in this article you’ll learn about
- Genes and from where genes come from?
- How does it survive and how are genes made up of?
- Alleles and how the genes and alleles inherited?
- Difference between genes and alleles
- What is the basic concept of, dominant and recessive and dominant and recessive alleles
- Difference between genotype and phenotype
- what is homozygous and heterozygous
Gene:
Gene encodes(responsible for safe and transfer of information and data) for a protein that impacts things like the immune system, skin, pigmentation, hormones production, and color of the eye. Genes inherit (comes) from parents to their progeny and are accountable for characteristic, quality, and trait that is passed from one generation to another generation.
From where genes come from?
As you know, genes are an important unit of living beings. Gene comes from parents to their offspring. Sometimes we also inherit physical or mental traits from our parents like any disease, condition, syndrome. Gene contains or feeds data and also maintains the cells. It also transmits information to their child.
- A cell contains two pairs of chromosomes. One set of chromosomes come from the father and another set of chromosomes comes from mother.
- The female egg or male sperm transfer single set of 23chromosomes, it may include 22 number of autosomes in “X” or “Y” sex chromosome.
- A male child inherits the “X” chromosome from mother and “Y” chromosome from father, while female children inherit “X” chromosomes from each patent.
Remember, you are male or female, you will always inherit one “X” chromosome from your mother, but your gender is determined by your father because they have ‘X’ and “Y” both chromosomes and they contribute one of them.
How does it survive or live?
Chromosomes have specialized structure and help to keep stay in DNA tightly swaddle around protein and are known as histones. If your DNA is not bound tightly with histone so, they might be too long and not fixed or fit inside the cell. The range in size is a few hundreds of DNA to more than two million DNA bases.
In humans, they have 23 pairs of chromosomes and the total number of chromosomes is 46. DNA passed from parents to their offspring during the reproductive process. A nucleotide is a building block of DNA, or it is based on three parts.
- Phosphate group
- Sugar group
- Nitrogen bases
Gene made up of:
Gene based on a long combination of four different nucleotide. These are,
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Thymine (T)
The letters ACGT are responsible for giving different characters to an individual.
Gene carries nucleotide-based latter ACGT as you know every person has a thousand Numbers of genes. Gene is the smallest section or part of DNA (double helix molecules) and this may be encoded (save the information) then allow the cross to manufacture specific products.
DNA?
DNA is a synthesized chemical that is present in the form of strands. All cells which exist in an individual have the same DNA, but each individual’s DNA is different. DNA is manufactured by long pair strands and becomes spiraled (gradually a tightening curve) into a double helix.
Alleles:
When genes mutate or change, they come in multiple forms and each form varies slightly in series on the basis of DNA. The genes alternate code for some traits (distinguish quality which belongs to person) like hair color but different in how traits are expressed (like brown or blonde hairs).
In simple words, the different sorts of some gene called allele.
As you know, alleles are series that encode for genes, a human being genotype for the gene is a set of alleles. In diploid organisms, two copies of allele make genotype for an individual.
- For example, Blossom color appears in species of flowers. So, nowhere, a single part of the gene is responsible for the color of petals but in many different versions of genes. One version is a red petal, and the other version is a white petal. Now the resulting or upcoming color of flowers depends on which allele is possessed for genes.
- Another example is, Human beings have a pair of homologous chromosomes (in somatic cells) and they contain two copies for each gene. Now an individual is known as heterozygous, while an individual who has two alleles is known as homozygous.
How genes and alleles inherit?
When humans give birth to the child, the child accepts 23 chromosomes from each parent (either mother or father). Each matching chromosome of one pair carries the same set of genes with distinctive genes located at certain spots known as gene locus (fixed position on a chromosome where genes exist). Inheritance means an individual has two copies of genes for trait (character or quality) e.i, one inherited from mother and one from father; this is also known as a maternal allele.
Difference between gene and allele:
Definition:
Gene: A gene is a portion of DNA that determines certain traits.
Allele: Alleles is a specific form of gene.
Function:
Gene: Gene is responsible for expression of trait.
Allele: Allele are responsible for variation in which given trait might he expressed.
Pairing:
Gene: Gene donors occur in pairs.
Allele: Allele occur in the form of pairs.
Location:
Gene: Gene are located in all known living organisms.
Allele: Allele can be identified in the multi genome of living organisms.
Worth:
Gene: Gene gave ability to create an individual.
Allele:Allele have the ability to bring differences to individuals in a population.
- An allele is a variant form of the gene and also encoded information for transmission of traits while the gene is a unit of genetic information. It gives instruction of guidance to make molecules of protein. Gene is carrying in size based on DNA. All human beings have two copies of genes that come from parents. Most genes are the same in all individuals, but some genres are somewhat different.
What is the dominant and recessive gene?
The biological term dominant and recessive actually explains the pattern of inheritance in some sort of trait. It defines how few phenotypes come in a child from a parent. These terms often become confusing to understand how genes identify a trait. This confusion comes in part because an individual note or observes a dominant or recessive inheritance pattern. You always need to understand how genes encode the pattern.
Dominant gene:
An inherited trait is said to be dominant if it shows only one copy of the gene and phenotypically Syndicate is heterozygous. It is due to when genes located on autosomes because non-sex chromosomes influence males and females both with the same probability and with equal severity.
Recessive gene:
Recessive genes make recessive phenotypes. Usually, recessive genes indicate when living beings have two recessive alleles from each parent and are also known as Homozygous.
Example of dominant and recessive gene:
Cleft Chin:
If you inherited a cleft chin, it means you have a dominant gene, but if you inherited a smooth chin, you have a recessive gene.
Rolling Tongue:
If you roll your tongue backside easily, this means you have inherited a dominant trait of genes, but if you are unable to do this, it means you inherit recessive genes for rolling of the tongue.
Handedness:
The gene for right-handedness means you inherited a dominant, while the gene for left-handedness means you have recessive.
Dimples:
All over the world, who have dimples, it means you inherited a dominant gene for dimples, but an individual who without dimples has recessive genes.
Freckles:
If you have freckles, it means you have inherited one pair of dominant genes for freckles, while if they are without freckles, it means you have inherited two recessive genes for freckles.
Earlobe Attachment:
If you have an unattached earlobe, it means you express dominance. While you have attached earlobes, it means you expressed recessive genes.
Dominant and recessive alleles:
The censorious point to discernment is, there is no universal specific or constant mechanism by which both alleles (either Recessive or dominant)act. Remember, dominant alleles nor physically dominant or subdued recessive alleles. Encode of a particular protein responsible for dominant and recessive alleles.
Dominant phenotype not always recessive phenotypes:
Let’s consider a typical single gene trait,
- Dominant allele + dominant allele = dominant phenotype
- Dominant allele + recessive allele = dominant phenotype
- Recessive allele + recessive allele = recessive phenotype
According to previous study, it is proven that recessive alleles present most of the population in very high numbers.
For example, eye color impacts due to two genes with small contributions from some others. An individual who has light eyes tends to transfer recessive alleles of vital genes, while an individual who has dark eyes tends to transfer dominant alleles.
Dominant allele are not away recessive alleles:
The method of inheritance from parents to their offspring has nothing to do with this. Either allele becomes beneficial for an individual or not.
For example, take a rock pocket mouse and the color of the fur is mainly controlled by a single gene. But the encoded gene fit protein produces dark pigmentation. Few rock pocket mice get the dark colors of fur and few pocket mice get the light color of fur.
Now the dark color of the fur allele is dominant and the light color of the fur allele is recessive. When mice live in dark habitats, they get dark fur because it makes mice concealed or less visible to predators while mice live in light rock or sand habitat, they get light fur.
So we can say that environment is matter, not allele is dominant or recessive.
What are genotype and phenotype?
Definition
Genotype: The term genotype referred to as the genetic composition of an individual means the hereditary information of an individual comes in the form of the gene and it may remain the same for the entire life.
Phenotype: The term phenotype refers to the visible physical appearance of an individual means the gene shown expression but with a certain time this character changes (from infant to child to young to adult).
Consist
Genotype: The hereditary character of an individual can or can not be expressed in the next generation.
Remember, if genotype is different it may produce simple genotype.
Example, RR and rr produce a similar color of eye whereas recessive allele is r and dominant allele is R.
Phenotype: In phenotype, characters do not come hu inheritance. It means phenotype can or cannot belong to a similar genotype.
Remember,if there is a small difference in phenotype it may result in different genotypes.
Inheritance
Genotype: Genotype partially comes from an organism to offspring during reproduction.
Phenotype: Phenotype is not inherited.
Appearance
Genotype: Genotype appears inside the body (genetic material).
Phenotype: Phenotype appears outside the body (physical appearance).
Determination
Genotype: Genotype can be determined by polymerase chain reaction (PCR) of an organism.
Phenotype: Phenotype can be determined by observation of an organism.
Affected
Genotype: Genotype affected by gene.
Phenotype: Phenotypes affect due to genotype or any environmental factors.
Example
Genotype: Blood group, color of eye and height are examples of genotype.
Phenotype: Hair color, color of eye and weight are examples of phenotype.
What is the difference between homozygous and heterozygous?
Definiaton
Homozygous: As you know, humans are diploid organisms if diploid organisms carry two copies of genes, but they might be identical (same) allele known as homozygous.
Heterozygous: If diploid organisms carry two copies of genes, but they become different (either dominant or recessive) alleles known as heterozygous.
Carries
Homozygous: It may carry similar (alike or same) allele of trait (example, TT, Tt).
Heterozygous: It may carry dissimilar (unlike or different) alleles of trait (example, Tt).
Allele type
Homozygous: An individual of homozygous carries a dominant or recessive allele but not both at same time.
Heterozygous: An individual of heterozygous having both (one dominant + one recessive) allele.
Types of gametes
Homozygous: Homozygous produce only one type of gamete.
Heterozygous: Heterozygous produce two types of gametes.
Result
Homozygous: The result of homozygous brings some individuals.
Heterozygous: The result of heterozygous brings dissimilar or different individuals.
- Homozygous or heterozygous are genetic terms used for identification because when living being produced, they develop a trait that comes for the combination of the dominant and recessive allele. Now how alleles are combined with identifying known as homozygous or heterozygous.