Answer:
The correct answer is A) Have diverse cell wall compositions
Explanation:
Both bacteria and archaea comes under prokaryotes because they both lack a membrane-bound nucleus. The difference between archaea and bacteria is in their cell wall composition.
The bacterial cell wall is made up of peptidoglycan and the archeal cell wall is made up of pseudo-peptidoglycan. In bacteria, peptidoglycan contains N acetyl muramic acid and N acetyl glucosamine unit but in archaea, the N acetyl muramic unit is replaced by some other unit and the linkage of two units is also different in archaea. So the right answer is A.
<span>Let's look at all the statements:Which of the following statements is true?
Parts of an ecosystem only include biotic factors such as plants and animals. - this is not true, it also includes abiotic factors, such as stones
If a common plant in an ecosystem becomes diseased, the ecosystem may become unbalanced. - this is the true statement! it could be a source of food for other animals, and thus it could influence the population of other species
Abiotic factors include decomposers such as fungi and bacteria. - this is false, those are biotic factors.
Tundras have a high diversity of species. - this is not true - compared to the rain forest, for example, tundras are not very diverse</span>
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:
Moistens tissues especially those that belong to the eye, the nose and mouth.
Water in the body also regulates body temperature.
It transports oxygen and nutrients to the cells.
It also helps to prevent constipation.
