1. Ovulation is the release of the egg from a woman's ovary.
2. The process of combining the male gamete, or sperm, with the female gamete, or ovum.
3. Solid mass of blastomeres resulting from a number of cleavages of a zygote, or fertilized egg.
4. A cavity appears in the morula between the cells of the inner cell mass and the enveloping layer.
5. The gastrula develops from the hollow, single-layered ball of cells called a blastula which itself is the product of the repeated cell division, or cleavage, of a fertilized egg.
6. Refers to the folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube.
7. In the second trimester of pregnancy -- months 4, 5, and 6 -- your baby's fingers and toes are well-defined. Their eyelids, eyebrows, eyelashes, nails, and hair are formed, and teeth and bones are becoming denser. Your baby can even suck their thumb, yawn, stretch, and make faces.
8. Your baby's hearing is fully developed and they change position frequently and responds to stimuli, including sound, pain, and light.