No I have not completed it but, I'd be happy to help you with any other questions you might have.
Answer: Option E (B and D are the only examples.
Mediterranean ecosystem with hot dry summer and fire can be found on various continents across the globe. Plants in these ecosystem have evolve similar adaptations to survive these circumstances.
Echidnas are egg laying mammals that live in Australia and new Guinea. They are sometimes known as spiny anteaters since they are covered in spines and mostly eat ants and termites. As such they resemble south American anteaters and hedgehogs but are not closely related to them. Instead echidnas descended from an aquatic platypus like ancestor.
Explanation:
Divergent evolution is a process where different organisms with different anscetors evolve independently and develop similar traits due to their adaptation to similar environment.
Another example is the similarities between hummingbird and hummingbird moth, the evolved from different ancestors and yet posses similar characteristics.
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 time required for a typical atom in the oceanic plate to complete the plate tectonic cycle is about in excess of two hundred fifty million years in which this is required for it to developed and to be fully complete for it to fully finish the plate tectonic cycle.
