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:
Carl Von Linneaus developed the system for classifying organisms.
<u>Answer</u>:
1.a) Species. It is the lowest taxon and represents the scientific name of the organism.
b) The species name is part of the binomial system of nomenclature developed by Linnaeus.
Thus it is composed of two parts each with its own writing rules (ex. gray wolf - <em>Canis lupus</em>):
A. the genus or generic name
- written first
- always underlined or italicized
- the first letter is always capitalized
ex. <em>Canis</em>
B. the specific epithet or species name
- is written second
- always underlined or italicized
- never capitalized
ex. <em>lupus</em>
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2. The results should always be the same. A dichotomous key is an identification tool based on a series of choices between alternative characters (dichotomous = divided into two parts). Thus, there is no room for subjective observation that may lead to another result. If the morphological traits of the organism are correctly identified, the the result should always be the same. Any differences occur due to errors on the scientist's part.
Yes, they do eat turkey on thanksgiving unless they don't like the taste of it.
Answer:
The economic principle that helps ensure that scarce resources are allocated efficiently is "the profit motive."
Explanation:
In economics, the profit motive is the inspiration of organizations that function so as to exploit their profits. Conventional micro-economic concept suggests that the eventual goal of a commercial is to make money. Specified differently, the aim for a business's presence is to chance a profit. The profit motive is the craving to make money. In a free market (where people willingly swap money, goods and services, the profit motive agrees who grows what. In theory, the profit motive dispenses resources efficiently, but in practice there are some problems.
