Answer;
-mutations of genes in an organism's sex cells
-recombination of existing genes during sexual reproduction
Explanation;
-Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other. One of the most notable examples of recombination takes place during meiosis (specifically, during prophase I), when homologous chromosomes line up in pairs and swap segments of DNA.
-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.
Answer:
The correct answers are:
3)mutations of genes in an organism's sex cells and 4)recombination of existing genes during sexual reproduction
Explanation:
Heritable characteristics are those characteristics that can pass to a new generation. Mutation in sex cells can cause change in nucleotide sequence which can code for some new traits and it can be passed in the offspring during the time of fertilization.
Sexual reproduction also results in an offspring with unique heritable characteristics because there is a recombination of existing genes of two individuals in sexual reproduction which brings genetic variation in the offspring. This variation results in getting unique heritable characteristics in offspring. Therefore the right answer is 3 and 4.
