Embryonic Development

Advanced anagen is the stage where the hair follicle is fully developed and reaches its maximum depth in the skin. Early anagen is the beginning of growth, while catagen and telogen are regression and resting phases.

During the catagen phase, the hair follicle shrinks and the base of the hair keratinizes to form a club hair as it detaches from the dermal papilla.

Monozygotic twins are those twins in which is zygote is fertilized by one sperm and during the cleavage, it gets divided into two separate zygotes. These type of twins are exactly identical.

Dizygotic twins may occur if two or more oocytes are released in one cycle. If each is fertilized, dizygotic twins may result. Fertility drugs are a common cause for dizygotic twins, but other factors, like family history, maternal age or weight, can also lead to dizygotic twinning. Thus, the correct answer is option D.

All epithelia are separated from their underlying tissues by an extracellular basement membrane which is fibrous in nature. The basement membrane is the fusion of two lamina namely, the basal lamina and the reticular lamina. The lamina reticularis is attached to the basal lamina with collagen anchoring fibrils and fibrillin microfibrils. The two layers together are collectively referred to as the basement membrane.

Blastula differentiate into various regions and cells (blastomeres) of a particular region form a particular part of adult body, hence these areas are called presumptive areas and at this stage if cells of a particular area removed the adult lacks a particular part from its body.

In microlecithal eggs or alecithal eggs, the cleavage results in the production of closely packed blastomeres. The stage in which solid mass of blastomeres appears is said to be morula, whereas blastula is hollow with a cavity known as blastocoel.

Hematopoiesis is the formation of blood cellular components. In developing embryo, blood formation occurs in aggregates of blood cells in the yolk sac called, blood islands. As development progresses, blood formation occurs in the spleen, lymph nodes, and liver. 

In Intra-Uterine Transfer (IUT) embryo with more than 8-blastomeres stage (morula) is used for transfer into the uterus after induced fertilisation in the laboaratory.

The zygote or early embryo (upto 8 blastomeres stage) is transferred to fallopian tube called zygote intra fallopian transfer or ZIFT. IUT (Intrauterine transfer), the embryo with more than 8 blastomeres is transferred into the uterus. So, the correct answer is 'Uterus'.

In vitro fertilization stands for fertilization outside the body in almost similar condition as that in the body is a method of assisted reproductive technology. In this method to ovum from the wife or donor and sperm from the husband of doner are collected and fused to form zygote in the simulated condition in the laboratory. The zygote or the early embryo up to 8 blastomeres is transferred into the fallopian tube which is known as zygote intrafallopian transfer when the embryos are more than 8 blastomeres then they are transferred into the uterus and this is known as an intrauterine transfer.

Schizocoelom develops as a split in the mesoderm, e.g.-Arthropods, Annelids, and Molluscs. Enterocoelom is derived from the wall of embryonic gut, e.g.-Echinoderms, and Chordates. Haemocoel is the blood-filled cavity of arthropods. Pseudocoelom is also known as a false cavity.

• The respiratory system represents the organs that are involved in the exchange of oxygen and carbon dioxide between the organism and the environment.
• In animals, a primary layer of cells is formed during embryogenesis, three in number and are differentiated as ectoderm, mesoderm, and endoderm. The tissues produced by these layers give rise to the organs of the body. 
• The respiratory tract with tracheae, bronchi, alveoli of the lungs is developed from the endoderm. The mesoderm forms the mesothelium from which lines the thoracic cavity and external intercostal muscles.
  Hence, the correct answer is D.

Histogen theory was proposed by Hanstein in 1870. According to this theory,  shoot apical meristem consists three distinct zones namely, dermatogen (external layer) which form outer covering of all organ of plant. Periblem (middle layer) which gives rise to cortex and endodermis. Plerome (central layer) which forms pith and primary vascular bundle. 
Thus, the correct answer is option C.

During embryonic development, the cells are pluripotent, meaning they have the capability to develop and differentiate into almost all cell types including muscle cells. Precisely, muscle cells are formed from the mesoderm of the embryo. So, the correct answer is ‘Embryonic development’.