Answer:
The C. elegans embryo is a powerful model system for studying the mechanics of metazoan cell division. Its primary advantage is that the architecture of the syncytial gonad makes it possible to use RNAi to generate oocytes whose cytoplasm is reproducibly (typically >95%) depleted of targeted essential gene products via a process that does not depend exclusively on intrinsic protein turnover. The depleted oocytes can then be analyzed as they attempt their first mitotic division following fertilization. Here we outline the characteristics that contribute to the usefulness of the C. elegans embryo for cell division studies. We provide a timeline for the first embryonic mitosis and highlight some of its key features. We also summarize some of the recent discoveries made using this system, particularly in the areas of nuclear envelope assembly/ dissassembly, centrosome dynamics, formation of the mitotic spindle, kinetochore assembly, chromosome segregation, and cytokinesis.
1. The C. elegans embryo as a system to study cell division
The C. elegans embryo is a powerful model system for studying the mechanics of metazoan cell division. Its primary advantage is that the syncytial gonad makes it possible to use RNA interference (RNAi) to generate oocytes whose cytoplasm is reproducibly (>95%) depleted of targeted essential gene products. Introduction of dsRNA rapidly catalyzes the destruction of the corresponding mRNA in many different systems. However, depletion of pre-existing protein is generally a slow process that depends on the half-life of the targeted protein. In contrast, in the C. elegans gonad, the protein present when the dsRNA is introduced is depleted by the continual packaging of maternal cytoplasm into oocytes (Figure 1). Since depletion relies on the rate of embryo production instead of protein half-life, the kinetics tend to be similar for different targets. By 36-48 hours after introduction of the dsRNA, newly formed oocytes are typically >95% depleted of the target protein.
Explanation:
The fact that they can breed but cannot produce fertile offspring shows that they are different species. T<span>hey may have different characteristics which means they cannot breed </span>successfully, too.
I hope this helps! :-)
xo Leafling
Answer;
When we will travel south from a taiga into a temperate forest we will observe 1. Increased precipitation as in taiga the prevailing climatic conditions are still harsh with less rain fall where as in temperate forest precipitation ranges from about 70 to 150 cm annually. 2. Increase in temperature as taiga has long, severe winters and short, mild summers whereas the average temperature in temperate forest is around 50 degree Celsius. 3. Change towards hardwood (deciduous) trees as Taiga, forms an almost continuous belt of coniferous trees worldwide whereas Temperate or deciduous forests are dominated by broad-leaved hardwood trees
Answer:
It is an ongoing process because species and communities continue to evolve over time.
Explanation:
Sweating (to try to remain cool) and increased heart rate (to help deliver oxygen to muscles faster)
