Pre-embryo - human development, Biology

Assignment Help:

Pre-Embryo - Human Development

About thirty hours after fertilization the zygote goes through mitosis giving rise to 2 blastomeres. These blastomeres go through further cleavages and by the 3rd day after fertilization, the tiny mass of cells reaches the uterus. Through this time it is a solid ball of cells called morula. In the next three days the morula is changed into a hollow ball of cells called blastocyst. The cavity of blastocyst is filled along with fluid secreted by the cells. One portion of the blastocyst consists of a concentrated mass of cells that will give rise to the entire body of the new individual. This is termed as the inner cell mass (ICM). Interestingly, each cell of this mass has the capability to develop into a complete individual. Identical twins are formed if the ICM splits. The outer ring of cells of the blastocyst surrounding its cavity is termed as trophoblast and gives rise to all the extra-embryonic membranes including much more of the placenta. This stage of development is important as the cells begin to move for the first time and become rearranged to shape the new individual. This procedure you might recall is the beginning of morphogenesis. However the major morphogenetic events occur during the third to eighth week.


Related Discussions:- Pre-embryo - human development

Name the animals having a single opening as mouth and anus, One example of ...

One example of animals having a single opening to the outside that serves both as mouth as well as anus is: 1. Octopus 2. Asterias 3. Ascidia 4. Fasciola Ascidia i

Name the common nitrogen-fixer in paddy field, The common nitrogen-fixer in...

The common nitrogen-fixer in paddy fields is: 1. Rhizobium 2. Azospirillum 3. Oscillatoria 4. Frankia Azospirillum is the common nitrogen-fixer in paddy fields

Symptoms of botulism, Adult Botulism The symptoms of botulism may deve...

Adult Botulism The symptoms of botulism may develop between 12 and 72 hours after the ingestion of toxin containing foods. Symptoms include nausea, vomiting, fatigue, dizzine

Terms of incubation time and the generation time, If the generation time (t...

If the generation time (t) is the incubation time (t) per generation (G), or t = t/G, rewrite the formula you derived in question 2 for bacterial population growth in terms of incu

When aerobic cells carry out fermentation, Under which conditions do aerobi...

Under which conditions do aerobic cells carry out fermentation? Some cells that as a rule get energy from aerobic cellular respiration can carry out fermentation when oxygen is

Define the goals of treatment of obesity, Define the Goals of treatment of ...

Define the Goals of treatment of Obesity? As said in the beginning, the goal of treatment of obesity today has shifted from mere 'weight loss' to 'weight management'. Each weig

What do you determine by atriopore, What do you determine by Atriopore? ...

What do you determine by Atriopore? The external opening to atrium. In cephalochordates water passes across pharyngeal slits into atrium and from there leaves through atriopore

Nervous system of echinoderms, Nervous System of Echinoderms Previous ...

Nervous System of Echinoderms Previous to studying the nervous system of echinoderms, you have to bear in mind the peculiar organization of these animals. Here as well, the ne

Dfine integrated child development services (icds), Dfine Integrated Child ...

Dfine Integrated Child Development Services (ICDS)? The adolescent girl scheme under ICDS intends to cover school dropout girls, 11-18 years in age with a view to meet their ne

Programmes directed towards the common crop plants, Programmes directed tow...

Programmes directed towards the common crop plants These programmes can be directed towards incorporating the following traits among common crop plants. Non-photo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd