Before gastrula formation can occur, the cells of the trophoblast are differentiated into two layers – one is an outer layer of protoplasm that contains the nuclei called the syncytium and the ...

DR. COUPIN has produced a descriptive account of gamete and zygote formation in the principal kinds of plants and animals, with 112 figures and an index of the names of the plants and animals ...

The zygote has 46 chromosomes. Some religions state dogmatically that life, personhood and “ensoulment” happen at the moment of zygote formation.

In Peridinium inconspicuum Lemmermann, sexual reproduction occurs in both nitrogen-enriched and nitrogen-deficient media. In this homothallic strain, protoplasmic fusion begins between two thecate ...

Once an egg is released from the ovary during ovulation, it meets with a sperm cell that was carried to it via the semen. These two gametes combine to form a zygote and this process is called ...