ZOO501 Final Term Current Papers Solved Updated

ZOO501 Final Current Solved (Update)

Exon Intron?

Both introns and exons are the genetic material. But the essential difference between the two is that one is made into protein and the other is not. DNA molecules are made up of small molecules that are called nucleic acids. An exon is a sequence of nucleic acids that are represented in the mRNA molecule.

How to avoid polyspermy?

o prevent the entry of more than one sperm into the egg. The sea urchin egg has two mechanisms to avoid polyspermy: a fast reaction, accomplished by an electric change in the egg plasma membrane, and a slower reaction, caused by the exocytosis of the cortical granules

Defect of neurulation?

Neural tube defects (NTDs) are severe congenital malformations affecting 1 in every 1000 pregnancies. ' Open' NTDs result from failure of primary neurulationas seen in anencephaly, myelomeningocele (open spina bifida) and craniorachischisis.

Meroblastic cleavage?

meroblastic cleavage, wherein the early cell divisions do not cut through the yolk of the egg. These cells form a blastoderm.

Fraternal and Identical twin?

Twins are two offspring produced by the same pregnancy. Twins can be either monozygotic('identical'), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic ('fraternal'), meaning that each twindevelops from a separate egg and each egg is fertilized by its own sperm cell.

What is blastocyst?

Blastocyst Blastocyst: A thin-walled hollow structure in early embryonic development that contains a cluster of cells called the inner cell mass from which the embryo arises.

How acrosomal reaction initiate in sea urchin?

In the sea urchin, contact with egg jelly initiates the acrosome reaction, which is a calcium-mediated process. ... The acrosomal vesicle (green) fuses with the plasma membrane, releasing enzymes from the tip of the sperm that aid digestion of egg jelly.

How genetic material exchange in paramecium?

The micronucleus is the generative, or germline nucleus, containing the genetic material that is passed along from one generation to the next. Paramecium reproduces asexually, by binary fission. During reproduction, the macronucleus splits by a type of amitosis, and the micronuclei undergo mitosis.

What is fate of metencephalon?

The fate of the brain vesicles is determined by the combination of transcription factors. Signals from the secondary organizer, the anterior neural ridge and the mesencephalon–metencephalon boundary (isthmus), regulate expression of the transcription factors in the adjacent region and organize its fate.

Function of Placenta?

The placenta acts to provide oxygen and nutrients to the fetus, whilst removing carbon dioxide and other waste products. It metabolises a number of substances and can release metabolic products into maternal and/or fetal circulations.

What is campomelic dysplasia?

Campomelic dysplasia is a severe disorder that affects development of the skeleton, reproductive system, and other parts of the body. This condition is often life-threatening in the newborn period. The term "campomelic" comes from the Greek words for "bent limb."6 days ago

Name 4 level gene regulation? Level of gene regulation?

Two different pathways of neural crest cell? (10)

continue on their way toward the ventral midline of the belly.

The second migratory pathway takes the trunk neural crest cells ventrolaterally through the anterior half of each sclerotome. (Yehi Samjh aaya mazeed PPTS chk krain).

Mygonesis (10)

Myogenesis: The Development of Muscle Paracrine factors instruct the Myotome cells to become muscles by inducing them to synthesize the MyoD protein. Factors from the surrounding environment induce the Pax3 transcription factor. In the absence of other inhibitory transcription factors (such as those found in the sclerotome cells), Pax3 then activates the genes encoding two muscle-specific transcription factors, Myf5 and MyoD. MyoD and Myf5 belong to a family of transcription factors called the myogenic bHLH (basic helix-loop-helix) proteins (sometimes also referred to as the MyoD family). The proteins of this family all bind to similar sites on the DNA and activate muscle-specific genes. MyoD also directly activates its own gene. While Pax3 is found in several other cell types, the myogenic bHLH proteins are specific for muscle cells. Any cell making a myogenic bHLH transcription factor such as MyoD or Myf5 is committed to becoming a muscle cell. Transfection of genes encoding any of these myogenic proteins into a wide range of cultured cells converts those cells into muscle

(Internte)

Myogenesis is the formation of muscular tissue, particularly during embryonicdevelopment. Muscle fibers form from the fusion of myoblasts into multi-nucleated fibers called myotubes. ... In this stage, calcium ions are critical for development.

Primary and Secondary neurulation?

In primary neurulation, the cells surrounding the neural plate direct the neural plate cells to proliferate, invaginate, and pinch off from the surface to form a hollow tube. In secondary neurulation, the neural tube arises from a solid cord of cells that sinks into the embryo and subsequently hollows out to form a hollow tube. Neurulation in fishes is exclusively secondary

Cortical granule reaction?

Cortical granules are membrane-bound structures containing proteolytic enzymes. However, whereas each sperm contains one acrosomal vesicle, each sea urchin egg contains approximately 15,000 cortical granules

Embryonic Shield?

Also called embryonic shield. in the early embryo of mammals, the flattened inner cell mass that arises at the end of the blastocyst stage and from which theembryo begins to differentiate.

Slow block polyspermy?

The slow block to polyspermy begins within 10 seconds of fusion of the sperm and egg plasma membranes. A compound called inositol triphosphate (IP3) causes the release of Ca++ from intracellular stores in the egg endoplasmic reticulum.

Osteogenesis?

Osteogenesis imperfecta (OI), also known as brittle bone disease, is a group of genetic disorders that mainly affect the bones. It results in bones that break easily.

Types of Cleavage?

the entire cell is divided equally. Four major holoblastic cleavage types can be observed in general: radial, spiral, bilateral, and rotational. Egg cells that have larger quantities of yolk undergo meroblastic cleavage after fertilization, in which only a portion of the zygote undergoescleavage.

Response from egg to sperm?

The responses of the egg to the sperm can be divided into "early" responses, which occur within seconds of the cortical reaction, and "late" responses, which take place several minutes after fertilization begins.

Blastocoel function?

The blastocoel probably serves two major functions in frog embryos: (1) it permits cell migration during gastrulation, and (2) it prevents the cells beneath it from interacting prematurely with the cells above it.

Tunicate gastrulation?

Tunicates, like sea urchins and vertebrates, follow the deuterostome pattern of gastrulation in which the blastopore becomes the anus.Tunicate gastrulation is characterized by the invagination of the endoderm, the involution of the mesoderm, and the epiboly of the ectoderm

Protozoans? (2)

is an informal term for single-celled eukaryotes, either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris.

Stereoblastula? (2)

Blastulae produced by radial cleavage have no blastocoel and are called stereoblastulae.

Neural Tube Close? (2)

The failure of the entire neural tube to close over the entire body axis is called Craniorachischisis. Collectively, neural tube defects are not rare in humans, as they are seen in about 1 in every 500 live births.

Function of Enhancer? (3)

Enhancer function underlies regulatory processes by which cells establish patterns of gene expression. Recent results suggest that enhancers are specified by particular chromatin marks in pluripotent cells, which may be modified later in development to alter patterns of gene expression and cell differentiation choices.

Composition of hyaline membrane in Sea Urchin? (3)

The hyaline layer is actually made up of two layers, an outer lamina made primarily of hyalin protein and an inner lamina composed of fibropellin proteins

Blastocoel Function? (5)

The blastocoel probably serves two major functions in frog embryos: (1) it permits cell migration during gastrulation, and (2) it prevents the cells beneath it from interacting prematurely with the cells above it.

Blastomere cleavage? (5)

Production of a multicellular organism, many cells must be produced from the single-celled zygote. This task is accomplished by cleavage, a series of consecutive cell divisions. Cells produced during cleavage are called blastomeres.

Primary and Secondary Neural tube?

The neural plate folds in upon itself to form the neural tube, which will later differentiate into the spinal cord and the brain, eventually forming the central nervous system. Different portions of the neural tube form by two different processes, called primary and secondary neurulation, in different species.

What is Blastocyst?

A mammalian blastula in which some differentiation of cells has occurred.

How acrosomal reaction initiate in Sea Urchin?

The acrosomal reaction in sea urchins is initiated by contact of the sperm with the egg jelly. Contact with egg jelly causes the exocytosis of the sperm's acrosomal vesicle and the release of proteolytic enzymes that can digest a path through the jelly coat to the egg surface.

What is Fete metacephone?

What is meroblastic Cleavage?

Depending mostly on the amount of yolk in the egg,cleavage can be holoblastic (complete or total) ormeroblastic (partial). In meroblastic cleavage, only a portion of the egg divides. This is because of the large amount of yolk in the egg cell that the cleavagefurrows do not penetrate the yolk. ... superficialcleavage.