. In humans, identical twins are possible because(A) extraembryonic cells interact with the zygote nucleus.(B) convergent extension occurs.(C) early blastomeres can form a complete embryo if isolated.(D) the gray crescent divides the dorsal-ventral axis into new cells.

Q: Discuss the process of gastrulation and embryonic folding?

A: Gastrulation is the process of cell relocation and distinction into three primary germ layers…

Q: List the four primary tissue types of the adult body and identify which of the three primary germ…

A: A tissue is defined as a group of cells which are having a similar structure and are organized to…

Q: Describe the movement of cells during early development that change an embryo from a blastula to a…

A: To describe: The movement of cells during early development that changes an embryo from a blastula…

Q: hy is it that the first trimester of pregnancy the most critical in humans? How will you relate it…

A: It is the early phase of pregnancy. The first trimester is marked as 1st day after your last period…

Q: At which embryonic event would one be able to first distinguish a diploblastic embryo from a…

A: Answer: In reproduction process after the fertilization of female egg cell with sperm male cell…

Q: What selective forces might limit the stage of development at which humans are born?

A: Introduction: The evolution of humans are influenced by the following five factors: Natural…

Q: If human fetus were exposed to very low levels of both testosterone and estrogen during prenatal…

A: People with both male and female anatomy and mixed characteristics are called as intersexes. The…

Q: How similar is the genetic information within each blastomere?

A: Blastomere: Its is a stage in early embryonic development. It is 2 celled structure formed by first…

Q: How do the shape and structure of the uterus of the fetal pig compare with that of the human?

A: Reproductive system is used for the sexual reproduction. Female internal reproductive organs include…

Q: Name the three primary germ layers and explain how they develop in the embryonic disc?

A: Once the implantation has successfully taken place, the cells start to divide and develop into an…

Q: Describe how the human blastocyst gives rise to the embryo and its extraembryonic membranes.

A: The fusion of male and female gametes form a zygote during fertilization.

Q: How do the location and the relative size of the bulbourethral glands of the fetal pig compare with…

A: Reproductive system is used for the sexual reproduction. Female internal reproductive organs include…

Q: What do you call the movement in which the yolk plug is formed in amphibians?

A: Introduction:- The residual patch of endodermal cells generated after the formation of the dorsal…

Q: Why do mammalian eggs have a small concentration of yolk, while bird and reptile eggs have a large…

A: Eggs are divided into three types on the basis of the amount of cytoplasm present in them. They are…

Q: Explain why growth of the blastomeres cannot take place  during cleavage?

A: Development in biology occurs to ensure the formation of multicellular organisms from the single…

Q: What are the functions of amniotic fluid?

A: The newborn fetus comes with an umbilical cord. This cord ends up with two umbilical arteries and…

Q: List and describe the phases of embryonic development; from a zygote through gastrulation.  What…

A: Reproduction is the process of the formation of offspring from their parents. There are two modes of…

Q: What structural features of the endometrium and myometrium contribute to their functions?

A: Uterus is one of the important organ of the female body. It serves many important functions in the…

Q: Name the three embryonic tissue layers of vertebrate embryos,and describe the process by which they…

A: Gastrulation is the cycle where differentiated cells from the zygote move to their particular areas.…

Q: If identical human twins develop from separate placentas, when must the embryo have separated? When…

A: Reproduction is the biological process through which the new individual organism is produced from…

Q: After the zygote undergoes several mitotic divisions, the resulting structure that implants in the…

A: Fertilization is the process in which gametes fuse to form a zygote. The zygote undergoes several…

Q: what characteristics are shared among bird embryos, pig embryos, and human embryos?

A: There are several similarities between the embryos of different species of animals and birds. It was…

Q: What's the process of gastrulation in humans, how the embryo forms the three germ layers, and which…

A: The inner cell mass which is known as Blastula is now grown into a cell mass known  Gastrula and…

Q: Identify and describe the stages of human embryonic development

A: Stages of embryonic developement: Germinal stage ~ Fertilization, cleavage, blastulation,…

Q: When viewing a 14-day old human embryo, could you identify the cranial and caudal ends? If yes,…

A: Gastrula is a three layered structure which transforms blastula into a complete organisms.

Q: Explain the implantation of blastula and differentiate the embryonic from extraembryonic tissues.

A: The development of multi-cellular organisms begins from a single-celled zygote, which undergoes…

Q: In a developing Chicken embryo, what is the fate of the postanal gut?

A: Postanal gut is the the extreme end of the alimentary canal.

Q: Identify two differences between a zygote and blastocyst

A: The fusion of male and female gametes is termed as fertilization. The process of fertilization takes…

Q: Are the extraembryonicmembranes the same in allvertebrates?

A: An embryo is an early phase development for an unborn baby. A small fertilized egg divides and grows…

Q: ''Because of the many later developmental trans-formations that produce the elaborately structured…

A: The germ layers develop early in embryonic life, through the process of gastrulation. Triploblastic…

Q: In human embryogenesis, how many hours does it take after fertilization to form the following; a.…

A: Embryogenesis  Embryogenesis refers to the stages of developing embryo. The embryogenesis start just…

Q: what evolutionary advantages does the amniotic egg have? explain how each component of the egg plays…

A: Allow embryos to grow faster and to a greater extent before hatching. Animals are no longer reliant…

Q: Implantation of a blastocyst does not always happen.  Approximately how many days after…

A: Fertilization of the secondary oocyte in the oviduct forms zygote which in turn divides by cleavage.…

Q: In the 33 hr. chick embryo stage what structure/s would serve as a guide to approximately…

A: Auditory vesicles are distinct. Three pairs of arterial arches arise from the ventral aorta. Somites…

Q: What are the four extraembryonic membranes of amniotic eggs of birds and other reptiles and what is…

A: Step 1 Extraembryonic membranes are those membranes that surround the embryo of terrestrial…

Q: A mammalian embryo puts the trophoblast into a hurried frenzy before it decides to proceed to the…

A: Trophoblasts refer to the cells that produce the external layer of a blastocyst. They can be seen…

Q: Regarding mammals, amphibians, and reptiles, explain thoroughly in what way does the inert yolk's…

A: Evolutionary developmental biology is considered a new norm in evolutionary biology. It arose from…

Q: What structures are derived from the ectoderm, mesoderm, and the endoderm?

A: Embryology is the study of development and growth of fertilized egg(zygote) into mature embryo. The…

Q: Explain the origins of the blastocyst cavity and what purpose does it serve?

A: The blastocyst is formed just after 5 days of fertilization.  It is composed of inner cell mass…

Q: What structures carry the egg from the ovaries to the uterus? Are these structures the same in all…

A: Introduction The ovary is a female reproductive organ that produces an egg called an ovum. This goes…

Q: What would happen if a blastocyst implanted into the functional layer of the endometrium and a…

A: It is at the blastocyst stage of development that an embryo would normally move out of the fallopian…

Q: How many follicle cells will fit inside? Is there an abundance of yolk within the cytoplasm of the…

A: Oocyte It is an immature ovum or egg cell which is a female gametocyte or germ cell. It is involved…

Q: What is the difference in gastrulation and blastula process?

A: Answer : the difference between gastulation and blastula process is :    Gastulation is the stage of…

Q: How can matter alone construct itself into the organized tissues of the embryo?

A: The embryo is the development stage in multicellular organisms. The development of the embryo begins…

Q: In a chicken embryo, What is the double membrane separating the pharyngeal pouch and furrow?

A: The animal body is a very complex creature made up of several systems. Each system in the body has a…

Q: To what extent has mesoderm migrated in the blastoderm of the 24 hour chick embryo

A: After twenty-one days of incubation, a chick emerges from a fertile egg. On the surface of the yolk,…