Skip to main content

The Principle of Inheritance & Variation | Biology Note online Class 12


Principle of Inheritance and Variation Biology Note online Class 12

 

What is Heredity?

Heredity is the process by which inherited characteristics are passed on from parents to their children. Genetics is a branch of biology dealing with principles and processes of inheritance and variation. Inheritance is the foundation of heredity, and it is by this mechanism that traits are passed on from parents to offspring.

 

Heredity refers to the transfer of traits from parents to their offspring through asexual or sexual reproduction. These traits or characteristics are present on the chromosomes in the form of genes.

 

Genes, which are located on chromosomes, are the fundamental unit of inheritance, and the difference between individuals of the same species is unavoidable. The expression of genes on chromosomes varies due to chromosome crossing, recombination, mutation, and environmental factors.

 

What is Inheritance? What is a variance?

The system of transferring characters from parent to offspring is known as inheritance. It is a fundamental concept in genetics. The degree to which descendants vary from their forefathers and mothers is referred to as variation. Individuals belonging to the same species can differ in terms of anatomy, physiology, cytology, and behavioral characteristics. The reshuffling of genes and chromosomes causes variations. Recombination or overcrossing.

The transfer of distinct inheritance groups or chromosomes from parents to offspring is included in inheritance. For paired pea traits, a scientist discovered that they were either dominant or recessive. When pure-bred parent plants were cross-bred, dominant traits were always visible in the progeny, while recessive traits were hidden before self-pollinating was left to the first-generation (F1) hybrid plants.

 

What are the different laws of heredity?

Law of Dominance: One of the alleles is dominant and in the case of the heterozygote, is reflected in the phenotype, e.g. we get all the tall plants with the genotype Tt in the offspring when we cross homozygous tall (TT) and dwarf (tt) plants, so tallness is a dominant trait over the dwarfness.

 

The Law of Gene Segregation states that during meiosis, each allele separates at the time of gamete formation. There is no mixing, and different gametes are assigned to different characters. Homozygotes produce only one type of gamete, while heterozygotes produce several types of gametes.

 

Independent Assortment Law: This states that alleles are separately inherited for various traits. He showed that a dihybrid cross was used.

 

Test Cross: It is to discover the dominant genotype of the plant by the plant being crossed with the recessive homozygote. The two findings are: if only the dominant feature is indicated by the phenotype of offspring, then the parent plant was homozygote to the dominant feature. If both phenotypes of the offspring are produced, then the parent plant was heterozygote to the dominant feature.

 

Read More About of Inheritance and Variation &  theory of chromosome.

 

Takshila Learning provides Tuition classes for online class 12 CBSE/ICSC. We provide the best Online Live classes for class 12 online classes  CBSE/ICSE Classes and other classes too that comprise Animated Video lectures and Live Online Classes. Get more NCERT Solutions for class 12 here.

 Book Free Demo Now, Visit Takshila Learning

OR Call Us @ 8800999280/83/84

 


Comments

Popular posts from this blog

Magnetic and non-magnetic material Class 6 Science

Magnetic and non-magnetic material  Class 6 Science A magnet is a substance that is drawn to certain magnetic materials like iron, cobalt, and nickel. Magnets have the ability to draw iron to them. Natural magnets are rocks that naturally draw iron. Non-magnetic materials include things like wood, rubber, coins, feathers, leather, etc. that are not drawn to iron. Magnet characteristics It pulls magnetic materials, such as iron. The magnet's two ends are referred to as its poles. The magnet's diametrically opposed poles are drawn together. Heating, hammering, or dropping causes it to lose its characteristics. On the basis of properties types of Magnets Temporary magnets are those magnets that are magnetic for only a little duration. Typically, iron, cobalt, or nickel are used to make them. When they are close to the powerful magnet, they act like a magnet. When they are yanked away from the powerful magnet, they stop being magnetic. Permanent magnets are magnets that have magne...

What are Noble Gases? Example and noble gases name

What are Noble Gases? Example and noble gases name Noble Gases Noble gases, sometimes known as inert gases or erosions, are part of the modern periodic table's 18th group. This group is made up of the following individuals: Helium is a kind of gas (He) Neon (Ne) Argon is a gas (Ar) Krypton  (Kr) Xenon is a kind of xenon gas (Xe) Radon is a gas that can cause cancer (Rn) Noble gases exist in a gaseous state under typical temperature and pressure conditions. Because all noble gases have stable electronic structures, they have very little chemical reactivity. They are monoatomic gases that do not readily form molecules. 'ns2np6' represents the basic electrical configuration of noble gases. As a result, noble gases' outermost valence shells can be deemed 'complete.' The chemical inertness of the group of 18 elements is due to this. Because of the stability of certain elements, these gases form a group. These stable elements' crusts are totally filled. Regardles...

CS Executive

At  Takshila Learning  we provide you Video Lecture of best faculties in India. We assure you not only the best quality of videos but also best content. Our teachers way of teaching, presentation and explanation is very simple and unique. Why Takshila Learning? We can give you 10 top reasons why you should take CS Executive Online Video Coaching Classes Lectures from Takshila Learnings. We are providing online classes of CS Executive for last 5 years (almost  oldest in the market ) We pick  best teachers  for every subjects. We don’t provide updates only with old videos. Infact we provide  new updated classes  for every attempt Our teachers update notes for every attempt. Videos and notes are  highly exams oriented . Our teachers  cover last 5 attempts question papers  along with ICSI Course content. Our video classes  includes live practical examples  to help you understand easily. Our structure of our  fee ...