Riprendimi

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DISCUSS WHICH KIND OF CLEAVAGE DOES AMPHIBIANS UNDERGO AND GIVE COMPLEHENSIVE EXPLANATION

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We will discuss about discoidal cleavage in amphibians by explaining the process and why this type of cleavage adaptive for their development.

What is Discoidal Cleavage?

Embryonic Development in Amphibians- Discoidal cleavage is seen amphibian embryo formation due to cytoplasmic distribution. A unique version of the blastula, referred to as the "discoidal blastula," exhibits a small circularized group of cells (the presumptive superficial layer) within which is found an in-tact inner nuclear vacuole with its central granules and some residual yolk.

Why Do Amphibians Show Discoidal Cleavage?

Limited Yolk Supply:

Amphibian eggs contain relatively little yolk when compared to the amount normally found in bird's egg. Because there is only a limited supply of yolk, the cytoplasm and yolk must be partitioned in such a way that each daughter cell has enough nutrients.

Discavage can be used to more accurately and controlled division of cell cytoplasm, allowing nutrient goes straight into the developing cells.

Developmental Efficiency:

The cleavage is equally efficient in partitioning cytoplasm and yolk because it constructs a small blastula buttressed by the yolk plug. Over a longer time period, this confers much greater control over the developmental processes and results in an embryo that is able to make it through development.

The small size of the blastula results in reduced demands on embryonic resources and can reduce errors that would be detrimental to development.

Avoid Polarity Problems

This discoidal cleavage help to define axis of development. This alignment and cell identity are important for following stages of embryonic development like gastrulation or organogenesis.

Having a clearly defined axis of development means the cells are dividing properly, leading to properly differentiated tissues and organs.

Controlled Cell Division:

Much of the control exerted on cleavage in amphibian eggs may simply be a consequence of their containing so little yolk and cytoplasm, but such low levels demand that very tight regulation occurs at each division to restrain fragmentation or disorganization.

This is the level of control discoidal cleavage provides — a prototype (14) in which the embryo carries out its development collectively. This regulated division also facilitates that the embryo can preserve its integrity and make sure it goes to become a functional being.

The partitioning of the zygote and its early cleavage pattern are discoidal because that helps in making this process efficient at one end and regulated from another due to limited provision for yolk storage involved. If an embryo does not undergo this type of cleavage, nutrients will not be distributed evenly and the developmental axis (which is as important to a developing embro/Fetus) has no clear path. This type of cleavage permits the amphibian embryo to develop into a fully coherent and functional organism, having organized its variety of cell types in an efficient manner by forming a small blastula with this sort of yolk plug.

The kind of cleavage that occurs in amphibians is very important because it determines the developmental potential and fate of the cells within the embryo. Cleavage refers to the process of cell division that occurs during early embryonic development, and the type of cleavage has a significant effect on tissue and organ formation in the organism.

In amphibians, cleavage is usually of the radial type, meaning that the planes of cleavage are oriented at right angles to the embryo's longitudinal axis. Cleavage of this sort produces cells much larger and more yolk-laden than those formed in other types of cleavage. Radial cleavage allows for several clearly defined layers of cells that will differentiate into various tissues and organs.

The type of cleavage is important in amphibians because it influences the overall development and also the morphology of the organism.

Like other vertebrates, amphibians do show cleavage as an early embryonic development process. Cleavage refers to rapid cell division rates that follow fertilization and result in a multicellular embryo. The type of cleavage given by the pattern specific to amphibians is called holoblastic cleavage.

Holoblastic cleavage refers to the complete division of the egg into separate cells. This type of cleavage occurs when the egg has either little or moderate amount yolk uniformly distributed throughout the cytoplasm. In contrast, meroblastic cleavage is seen in organisms with heavily yolked eggs like birds and reptiles and is characterized by incomplete division due to the large amount of yolk that impedes cell division.

In amphibians, during holoblastic cleavage, the zygote undergoes rapid mitotic divisions known as cleavage divisions. So rapid is their rate that little or no growth occur between them; hence, the increase in size is quite phenomenal.

In a nutshell amphibians generally exhibit holoblastic cleavage. Holoblastic cleavage is characteristic of yolk-rich eggs. In this type of cleavage, the entire egg structure divides into smaller cellular units during mitotic division. This kind of cleavage is typical for yolk-rich eggs since the yolk substance inhibits cell movement within the egg structure.In holoblastic cleavage of amphibians, the egg undergoes smaller cellular units by successive mitotic divisions. It is then the morula, which finally gives rise to a hollow ball of cells known as the blastula. The blastula undergoes gastrulation, which is the process by which the cells rearrange and differentiate to form germ layers that will produce various tissues and organs of the developing embryo.Holoblastic cleavage in amphibians is important during the initial development of the embryo to ensure that the right cells are produced and arranged prop to support

Good Morning Heartache
Riprendimi poster.jpg
Theatrical release poster
Riprendimi
Directed by Anna Negri
Screenplay by
  • Anna Negri
  • Giovanna Mori
Produced by
Starring
CinematographyGian Enrico Bianchi
Edited byIlaria Fraioli
Music by Dominik Scherrer
Production
company
Bess Movie
Distributed byMedusa Film
Release date
  • 11 April 2008 (2008-04-11)(Italy)
Running time
93 minutes
CountryItaly
Language Italian
Box office$278,471 [1]

Good Morning Heartache (Italian : Riprendimi) is an Italian comedy-drama film of 2008 written by Giovanna Mori and Anna Negri and is directed by the latter. [2] The film is a pseudo-documentary and a low-budget film [3] that was shot in Rome.

Cast

Acknowledgments

Sundance Film Festival

The film was featured at the 2008 Sundance Film Festival with the creator of the film Anna Negri. [4]

Awards and nominations

Related Research Articles

Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism.

<span class="mw-page-title-main">Ontogeny</span> Origination and development of an organism

Ontogeny is the origination and development of an organism, usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan.

<span class="mw-page-title-main">Embryo</span> Multicellular diploid eukaryote in its earliest stage of development

An embryo is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals.

<span class="mw-page-title-main">Embryology</span> Branch of biology studying prenatal biology

Embryology is the branch of animal biology that studies the prenatal development of gametes, fertilization, and development of embryos and fetuses. Additionally, embryology encompasses the study of congenital disorders that occur before birth, known as teratology.

<span class="mw-page-title-main">Blastulation</span> Sphere of cells formed during early embryonic development in animals

Blastulation is the stage in early animal embryonic development that produces the blastula. In mammalian development, the blastula develops into the blastocyst with a differentiated inner cell mass and an outer trophectoderm. The blastula is a hollow sphere of cells known as blastomeres surrounding an inner fluid-filled cavity called the blastocoel. Embryonic development begins with a sperm fertilizing an egg cell to become a zygote, which undergoes many cleavages to develop into a ball of cells called a morula. Only when the blastocoel is formed does the early embryo become a blastula. The blastula precedes the formation of the gastrula in which the germ layers of the embryo form.

<span class="mw-page-title-main">Gastrulation</span> Stage in embryonic development in which germ layers form

Gastrulation is the stage in the early embryonic development of most animals, during which the blastula, or in mammals the blastocyst, is reorganized into a two-layered or three-layered embryo known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body, and internalized one or more cell types including the prospective gut.

<span class="mw-page-title-main">Germ cell</span> Gamete-producing cell

A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Unlike animals, plants do not have germ cells designated in early development. Instead, germ cells can arise from somatic cells in the adult, such as the floral meristem of flowering plants.

<i>Drosophila</i> embryogenesis Embryogenesis of the fruit fly Drosophila, a popular model system

Drosophila embryogenesis, the process by which Drosophila embryos form, is a favorite model system for genetics and developmental biology. The study of its embryogenesis unlocked the century-long puzzle of how development was controlled, creating the field of evolutionary developmental biology. The small size, short generation time, and large brood size make it ideal for genetic studies. Transparent embryos facilitate developmental studies. Drosophila melanogaster was introduced into the field of genetic experiments by Thomas Hunt Morgan in 1909.

<span class="mw-page-title-main">Blastocoel</span> Fluid-filled or yolk-filled cavity that forms in the blastula

The blastocoel, also spelled blastocoele and blastocele, and also called cleavage cavity, or segmentation cavity is a fluid-filled or yolk-filled cavity that forms in the blastula during very early embryonic development. At this stage in mammals the blastula is called the blastocyst, which consists of an outer epithelium, the trophectoderm, enveloping the inner cell mass and the blastocoel.

A germ layer is a primary layer of cells that forms during embryonic development. The three germ layers in vertebrates are particularly pronounced; however, all eumetazoans produce two or three primary germ layers. Some animals, like cnidarians, produce two germ layers making them diploblastic. Other animals such as bilaterians produce a third layer between these two layers, making them triploblastic. Germ layers eventually give rise to all of an animal's tissues and organs through the process of organogenesis.

<span class="mw-page-title-main">Animal embryonic development</span> Process by which the embryo forms and develops

In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm cell (spermatozoon). Once fertilized, the ovum becomes a single diploid cell known as a zygote. The zygote undergoes mitotic divisions with no significant growth and cellular differentiation, leading to development of a multicellular embryo after passing through an organizational checkpoint during mid-embryogenesis. In mammals, the term refers chiefly to the early stages of prenatal development, whereas the terms fetus and fetal development describe later stages.

Isolecithal refers to the even distribution of yolk in the cytoplasm of ova of mammals and other vertebrates, notably fishes of the families Petromyzontidae, Amiidae, and Lepisosteidae. Isolecithal cells have two equal hemispheres of yolk. However, during cellular development, normally under the influence of gravity, some of the yolk settles to the bottom of the egg, producing an uneven distribution of yolky hemispheres. Such uneven cells are known as telolecithal and are common where there is sufficient yolk mass.

In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula. Cleavage ends with the formation of the blastula, or of the blastocyst in mammals.

An asymmetric cell division produces two daughter cells with different cellular fates. This is in contrast to symmetric cell divisions which give rise to daughter cells of equivalent fates. Notably, stem cells divide asymmetrically to give rise to two distinct daughter cells: one copy of the original stem cell as well as a second daughter programmed to differentiate into a non-stem cell fate.

In the field of developmental biology, regional differentiation is the process by which different areas are identified in the development of the early embryo. The process by which the cells become specified differs between organisms.

<span class="mw-page-title-main">Fish development</span>

The development of fishes is unique in some specific aspects compared to the development of other animals.

<span class="mw-page-title-main">Blastodisc</span> Embryo forming part of yolk

The blastodisc, also called the germinal disc, is the embryo-forming part on the yolk of the egg of an animal that undergoes discoidal meroblastic cleavage. Discoidal cleavage occurs in those animals with a large proportion of yolk in their eggs, and include insects, fish, reptiles and birds. The blastodisc is a small disc of cytoplasm that sits on top of the yolk. In birds, it is a small, circular, white spot on the surface of the yellow yolk of an egg, at the animal pole.

Telolecithal, refers to the uneven distribution of yolk in the cytoplasm of ova found in birds, reptiles, fish, and monotremes. The yolk is concentrated at one pole of the egg, separate from the developing embryo.

Embryogenesis in multicellular organisms can vary across taxonomic class or species. Organisms independent of aquatic habitats exhibit unique features during their embryonic development. Amphibians are notable as remnants of the first vertebrates capable of surviving in both aquatic and terrestrial environments. The embryonic development of tailless amphibians is presented below using the African clawed frog and the northern leopard frog as examples.

This glossary of developmental biology is a list of definitions of terms and concepts commonly used in the study of developmental biology and related disciplines in biology, including embryology and reproductive biology, primarily as they pertain to vertebrate animals and particularly to humans and other mammals. The developmental biology of invertebrates, plants, fungi, and other organisms is treated in other articles; e.g terms relating to the reproduction and development of insects are listed in Glossary of entomology, and those relating to plants are listed in Glossary of botany.

References

  1. ↑ "Foreign Movies: Riprendimi". Box Office Mojo . Retrieved 25 February 2018.
  2. ↑ "Trama E Cast: Riprendimi" [Plot And Cast: Good Morning Heartache] (in Italian). Coming Soon. 7 April 2008. Retrieved 25 February 2018.
  3. ↑ Gandolfi, Marzia (7 April 2008). "INCONTRI: Anna Negri gira un "documentario" sentimentale sul precariato e la sua influenza sui comportamenti sociali. – In principio era amore" [MEETINGS: Anna Negri turns a sentimental "documentary" on precariousness and its influence on social behavior. – In the beginning it was love]. MYmovies.it (in Italian). Retrieved 25 February 2018.
  4. ↑ "Festival Italy: Anna Negri at Sundance Festival". Cineuropa. Retrieved 25 February 2018.


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