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.
The gametes produced by an organism are determined by its sex: males produce male gametes (spermatozoa, or sperm, in animals; pollen in plants) while females produce female gametes (ova, or egg cells); individual organisms which produce both male and female gametes are termed hermaphroditic.rganisms of many species are specialized into male and female varieties, each known as a sex. Sexual reproduction involves the combining and mixing of genetic traits: specialized cells known as gametes combine to form offspring that inherit traits from each parent.