GermlineIn biology and genetics, the germline is the population of a multicellular organism's cells that develop into germ cells. In other words, they are the cells that form gametes (eggs and sperm), which can come together to form a zygote. They differentiate in the gonads from primordial germ cells into gametogonia, which develop into gametocytes, which develop into the final gametes. This process is known as gametogenesis.
Germ cellA germ cell is a cell that gives rise to a gamete, the reproductive cell of an animal or organism that reproduces sexually. In the female the resulting gamete is the egg cell, or ovum, and in the male the gamete is the sperm. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation.MeiosisCell division producing haploid gametesIn meiosis, the chromosomes duplicate (during interphase) and homologous chromosomes exchange genetic information (chromosomal crossover) during the first division, called meiosis I. The daughter cells divide again in meiosis II, splitting up sister chromatids to form haploid gametes.
Sexual reproductionSexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid).
Cell (biology)Basic unit of life formsThe cell is the basic structural and functional unit of all forms of life or organisms. The term comes from the Latin word cellula meaning 'small room'. A biological cell basically consists of a semipermeablecell membrane enclosing cytoplasm that contains genetic material. Most cells are only visible under a microscope.
MitosisMitosis () is a part of the cell cycle in eukaryotic cells in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained.
Multicellular organismA multicellular organism is an organism that consists of more than one cell, and more than one cell type, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus Dictyostelium.
GameteA gamete ( GAM-eet ), reproductive cell, or sex cell, is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. The name gamete was introduced by the German cytologist Eduard Strasburger in 1878. The type of gamete an organism produces determines its sex and sets the basis for the sexual roles and sexual selection. Female gametes are called ova or egg cells, and male gametes are called sperm.
Stem cellUnspecialized biological cell that can become specializedIn multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each.
GametocyteA gametocyte is a eukaryoticgerm cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called spermatocytes, and female gametocytes are called oocytes. DevelopmentThe development of gametogonia to primary gametocytes is called gametocytogenesis. The further development of primary gametocytes to secondary gametocytes is a part of gametidogenesis.
Cell biologyCell biology, cellular biology, or cytology, is the branch of biology that studies the structure, function, and behavior of the cells. All organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of an organism. Cell biology encompasses both prokaryotic and eukaryotic cells, with subtopics including the study of cell metabolism, cell communication, cell cycle, biochemistry, and cell composition.*As an Amazon Associate I earn from qualifying purchases.