Exploring Prenatal Development: Key Stages and Concepts Quiz

Fertilization in starfish involves the process of sexual reproduction where the sperm and egg unite internally to form a zygote, similar to many other organisms.

Biphasic refers to the process of cell divisions after fertilization, where daughter cells are half the size of mother cells.

Holoblastic cleavage is a type of embryonic cell division in which the entire zygote divides into separate blastomeres. It is commonly seen in various organisms including flatworms, annelids, molluscs, echinoderms, amphibians, and mammals. The incorrect answers describe different types of cleavage patterns that are distinct from holoblastic cleavage.

Meroblastic cleavage is a type of cleavage where only part of the zygote divides. This process is commonly seen in arthropods, cephalopods, fishes, reptiles, and birds.

Blastomeres are cells formed during cleavage divisions in developing embryos, not related to immune system cells, flower structures, or butterfly life cycle stages.

A morula in the context of a starfish refers to a stage in the development of the starfish embryo.

A blastula is a stage in the early development of an organism, specifically when it consists of approximately 64 cells and resembles a hollow sphere.

A Blastocoel specifically refers to the central cavity in a blastula, not to any of the other options provided.

The correct answer involves cells moving and changing to form the gastrula structure, not cell division, apoptosis, or fusion.

The neurula stage in chordates is characterized by the development of the notochord, neural tube, and coelom. This stage follows the gastrula stage in embryonic development.

The ectoderm is one of the three primary germ layers that give rise to the various tissues and organs of an organism. It specifically gives rise to the outer covering of the animal and in some phyla, to the central nervous system.

The mesoderm is a third layer in bilaterally symmetrical animals that plays a crucial role in filling up the space between the outer Ectoderm and inner Endoderm layers. It contributes to the development of muscles, skeleton, circulatory system, and other vital organs.

The endoderm is the innermost germ layer in an embryo, responsible for forming the lining of the digestive tract and organs like the liver and lungs in vertebrates. The incorrect answers do not correctly describe the endoderm, making them not suitable options.

Organogenesis refers to the process in which organs begin to form during embryological development.

Morphogenesis refers to the process of shaping an organism during development, rather than the study of genetic mutations, cellular respiration, or the formation of new species.

An isolecithal egg is characterized by its evenly distributed yolk particles and distinct nucleus, unlike the incorrect options provided.

Mesolecithal eggs have a specific distribution of yolk that distinguishes them from other types of eggs.

Telolecithal eggs are characterized by having a large concentration of yolk at one end, unlike evenly distributed yolk or enucleated eggs. A hard outer shell is not a defining characteristic of telolecithal eggs.

Centrolcithal eggs are characterized by having the yolk concentrated at the center of the egg, as opposed to other patterns like the yolk being at the periphery or spread evenly throughout.

Determinate cleavage refers to the specific patterns in which cells divide during early embryological development, with the fate of each cell being predetermined in some organisms.

Indeterminate cleavage refers to the ability of blastomeres in certain organisms to change their fate depending on their environment and interactions with neighboring cells.

A 12-hour chick embryo refers to an embryo that is 12 hours old since fertilization. Therefore, the correct answer is 12 hours.

The correct answer specifies the specific stage of development at 28 hours, while the incorrect answers provide alternative options that either suggest lack of development or different stages of development.

A 48-hour chick embryo is in the early embryonic stage of development, which is characterized by rapid cell division and differentiation.

After 56 hours, a chick embryo is in the early embryo stage of development, where the basic structures and organs are beginning to form.

The correct answer refers to a chick embryo that is 4 days old, which occurs after 96 hours of development.