Embryonic Development

Gastrulation involves a process of invagination at one end of blastula which results in the formation of two-layered cup-shaped gastrula. 

It is the correct answer. Liver and pancreas develop from endoderm.

A bi-or tricalpellary syncarpous unilocular ovary having one ovule at base represents the basal placementation.

An embryo may sometimes develop from an embryo sac other than egg. This is called apogamy. It is the development of an embryo without fertilization; especially the development in some ferns of a sporophyte from the gametophyte without fertilization.

Non-recurrent apomixis is where an embryo arises directly from a normal egg-cell without the process of fertilization. Egg cells are haploid and hence, the resulting embryo is also haploid. It includes haploid parthenogenesis, haploid apogamy and adrogamy.

The developing embryo has two main populations of cells: an inner cell mass and a trophectoderm. The trophectoderm cells lie at the outer surface of the developing embryo and will become the placenta.

Mesenchyme arising beneath the germinal epithelium in the testes is the precursor to testicular interstitial cells, or Leydig cells, while in the ovaries it is the precursor to ovarian stroma or thecal cells.

It is the correct option, it forms the outer layer of skin and nervous system.

It is the primitive gut that forms during gastrulation in the developing embryo. 

Synergids direct the growth of pollen tube by secreting some chemical substances.

It is an egg that has little yolk.

It is the process of differentiation of cells at specific places in the germ layer to form tissue, organ and organ system.

It is the attachment of blastocyst to the uterine wall.

It is the covering of heart called the pericardium, and the membrane that surrounds the lungs is called the pleura. It is produced by mesoderm.

It is a small sac that pushes out from the gut of embryo near the yolk sac.