What is a variation in biology?


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Variation can be defined as any difference between the individuals in a species or groups of organisms of any species. The mutation is the ultimate source of genetic variation, but mechanisms such as sexual reproduction and gene flow contribute to it as well.

How are variations expressed in organisms?

Variation may be shown in physical appearance, metabolism, fertility, mode of reproduction, behaviour, learning and mental ability, and other obvious or measurable characters. Genotypic variations are caused by differences in number or structure of chromosomes or by differences in the genes carried by the chromosomes.

What is variations in gene expression?

Variation in gene expression constitutes an important source of biological variability within and between populations that is likely to contribute significantly to phenotypic diversity. Recent conceptual, technical, and methodological advances have enabled the genome-scale dissection of transcriptional variation.

How does genetic variation occur?

Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).

What is an example of variation in biology?

Variation refers to the difference between two individuals of a species. Genetic variation arises due to mutation and recombination during meiosis. Examples of variation are different skin colour, eys, height, resistance to diseases, etc.

What are the 3 sources of variation?

The genetic diversity has three different sources: mutation, recombination and immigration of genes. Mutation is the driving force of genetic variation and evolution.

What determines the expression of traits?

Traits can be determined by genes, environmental factors or by a combination of both. Traits can be qualitative (such as eye color) or quantitative (such as height or blood pressure). A given trait is part of an individual’s overall phenotype.

What is variation in evolution?

Variation is the difference in the characteristics of individuals in a population. They occur due to recombination and mutation, whereas evolution is the gradual process of change in inheritable characteristics of a population over several generations. Evolution occurs through natural selection.

How is genetic variation measured?

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How is genetic variation measured in a population?

Genetic variation within a population is measured according to the number of different alleles of all genes and the frequency with which they appear. Variation is high when there are many different allelic forms of all genes and when there are many different combinations of those alleles.

What happens when a gene is expressed?

Gene expression is that process of turning on a specific gene to start making messenger RNA. The messenger RNA can then perform intended jobs in the cell, such as forming proteins. Gene expression controls both whether or not the messenger RNA is made, as well as how much messenger RNA is made at that time.

What are the two main causes of variation?

The two main causes of variation are mutation and genetic recombination in sexual reproduction.

What is genetic variation quizlet?

Genetic variation is the diversity present in the DNA of a population. Increased variation provides phenotypic changes that can be selected for or against by natural selection. Increased genetic variation also provides an advantage in adapting to changing environments.

Why does variation occur in population?

The main reasons for variations in a population are mutation and genetic recombination during sexual reproduction.

What are the 4 types of variation in biology?

Variations mean the differences (morphological, physiological, cytological and behaviouristic) amongst the individuals of the same species and the offspring of the same parents. They are found in all the characters and in every conceivable direction. Therefore, no two individuals are similar.

What is an example of variation within a species?

Variation within species affects how organisms interact with each other and their surrounding environment. For example, the size of a fish’s mouth, known as its gape, varies and determines the size of prey it can eat.

How many types of variations are there in biology?

Variations can be categorised into two types: Genotypic variations are caused due to changes in the chromosome or genes or due to various alleles of the same gene. They are inheritable variations. These are caused due to mutation, recombination, etc.

What is the main source of genetic variation?

Mutations are the original source of genetic variation. A mutation is a permanent alteration to a DNA sequence. De novo (new) mutations occur when there is an error during DNA replication that is not corrected by DNA repair enzymes.

What are the 5 causes of genetic variation?

Mutation, gene flow, sexual reproduction, random mating between organisms, random fertilization, and crossing over are the main cause of genetic variation.

What factors influence gene expression?

Environmental factors such as diet, temperature, oxygen levels, humidity, light cycles, and the presence of mutagens can all impact which of an animal’s genes are expressed, which ultimately affects the animal’s phenotype.

How do traits get expressed explain with an example?

For example the height of a plant depends on the hormone. The amount of hormone depends on the process of its formation. A protein is important for this process. If this protein works efficiently a lot of hormones will be made.

How genes that determine traits are expressed?

Traits are inherited characteristics from our parents that are expressed externally in our phenotype. For any given trait, one gene variation (allele) is received from the father and one from the mother. The expression of these alleles determines the phenotype, whether dominant or recessive.

What are the three major steps of gene expression?

The process of gene regulation includes 1) transcription, the conversion of DNA to RNA, and 2) translation, the conversion of RNA to proteins.

Why do we do gene expression?

Gene expression is a tightly regulated process that allows a cell to respond to its changing environment. It acts as both an on/off switch to control when proteins are made and also a volume control that increases or decreases the amount of proteins made.

What is gene expression example?

Some simple examples of where gene expression is important are: Control of insulin expression so it gives a signal for blood glucose regulation. X chromosome inactivation in female mammals to prevent an “overdose” of the genes it contains. Cyclin expression levels control progression through the eukaryotic cell cycle.

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