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:
Answer:
Barroreceptors are specific type of receptors that are present within the membrane or wells of the blood vessels and monitor the changes occur in blood pressure.
The major and important barroreceptors are located in carotid sinus and the aorta for detecting fluctuation in the blood pressure. If blood pressure falls these receptors firing rate decreases and barroceptors reflexes act to increase heart rate in order to restore blood pressure in an individual.
Thus, the correct answer would be - increasing heart rate.
When you cut up the carrot you increase the surface area of the carrot substantially. This increased surface area reacts with the atmosphere and makes the carrot (collectively the pieces) more exposed to bacteria and as a result the cut up carrots will go bad before the carrots as a whole.
Answer: They are the stop codon
Explanation: At the end of and mRNA squence there are three nucleotides that tell the ribosome to end the protein being made.
