What ensures that genetic variation occurs in offspring?
What ensures that genetic variation occurs in offspring?
Genetic variation is increased by meiosis During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote.
How does reproduction produce variation in offspring?
The process of sexual reproduction introduces variation into the species because the alleles that the mother and the father carry are mixed together in the offspring. A mate must be found, the egg must be fertilised by sperm, and then the offspring develop.
Why is variation in the offspring produced?
The number of cells increases by mitosis, and as the embryo develops, the cells begin to differentiate (or specialise). As half of the genetic make-up of the offspring is from one organism and half from another, it is genetically different from its parents. In other words, it shows variation.
What process provides variety in offspring?
Reproduction (or procreation) is the biological process by which new “offspring” (individual organisms) are produced from their “parents. ” It is a fundamental feature of all known life that each individual organism exists as the result of reproduction.
What is variation and its importance?
Variation is important because it causes evolution and is the basis of heredity. It is advantageous to a population as it enables few individuals to adapt to the environment changes thus, enabling the survival of the population.
What produces offspring that have the same DNA as the parent?
Asexual reproduction produces offspring that are genetically identical to the parent, whereas sexual reproduction produces a similar, but genetically unique offspring. In sexual reproduction, meiosis produces haploid gametes that fuse during fertilization to produce a diploid zygote (Figure below).
How does sexual reproduction lead to genetic variation?
Discusses cellular processes that produce genetically unique individuals. … Loading… Found a content error? Describes how sexual reproduction leads to genetic variation. .
Why is sexual reproduction important to the survival of the species?
Sexual reproduction ensures a mixing of the gene pool of the species. The variations found in offspring of sexual reproduction allow some individuals to be better suited for survival and provide a mechanism for selective adaptation to occur.
Which is favoured by evolution K-selection or r-selection?
These two main strategies are known as K-selection (few offspring) and r-selection (many offspring). Which strategy is favoured by evolution depends on a variety of circumstances. Animals with few offspring can devote more resources to the nurturing and protection of each individual offspring, thus reducing the need for many offspring.
Which is the first source of genetic variation produced by meiosis?
The crossover events are the first source of genetic variation in the nuclei produced by meiosis. A single crossover event between homologous non-sister chromatids leads to a reciprocal exchange of equivalent DNA between a maternal chromosome and a paternal chromosome.
Which is another source of genetic variation in offspring?
It is obviously another source of genetic variation in offspring. This is known as random fertilization. All of these mechanisms working together result in an amazing amount of potential variation. Each human couple, for example, has the potential to produce more than 64 trillion genetically unique children. No wonder we are all different!
Why is genetic variation an important force in evolution?
Genetic variation is a measure of the variation that exists in the genetic makeup of individuals within population. Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population.
How are sexual reproduction and meiosis related to genetic variation?
Section C: Origins of Genetic Variation 1.Sexual life cycles produce genetic variation among offspring 2. Evolutionary adaptation depends on a population’s genetic variation •The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises each generation during sexual reproduction.
How does independent assortment of chromosomes contribute to genetic variability?
•Independent assortment of chromosomes contributes to genetic variability due to the random orientation of tetrads at the metaphase plate. •There is a fifty-fifty chance that a particular daughter cell of meiosis I will get the maternal chromosome of a certain homologous pair and a fifty-fifty chance that it will receive the paternal chromosome.