Left bundle branch block is a problem with the heartâs electrical wiring system. Your heart has 4 chambers. The 2 upper chambers are called atria, and the 2 lower chambers are called ventricles.
The process of sexual reproduction involves two parents, each contributing one gamete. Gametes are produced. by a process called meiosis, which starts by the duplication of the chromosomes, followed by two rounds of cell divisions and halving of the chromosome number.Gametes have half the chromosome number of other adult. cells of an organism.A key feature of meiosis is the exchange of chromosome pieces which occurs in the first division of this process, called recombination or crossing over.ametes have half the chromosome number of other adult. cells of an organism. A key feature of meiosis is the exchange of chromosome pieces which occurs in the first division of this process, called recombination or crossing over.
As in all other organisms reproduction is the formation of new individuals of the same species. Sexual. reproduction is the only method of reproduction in our species. Sexual reproduction involves the fusion of specialised haploid sex cells.The fusion of sperm and egg cell is called fertilisation.Fertilisation results in the formation of a diploid zygote from which a new individual develops.exual reproduction involves the fusion of specialised haploid sex cells. The fusion of sperm and egg cell is called fertilisation. Fertilisation results in the formation of a diploid zygote from which a new individual develops.