Answer:
C
Explanation:
The nucleus contains most of the dna and the mitochondria contains a small amount
The gene. A trait is a characteristic of a person that can be passed on. But it is the gene, not the trait that is inherited
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:
Humoral immunity involves <u>B cells</u> and<u> recognize antigens or pathogens in the lymph or blood.</u>
Explanation:
Humoral immunity is defined as the immunity which is mediated by several macromolecules presnet in the extracellular fluids such as antibodies, certain antimicrobial peptides, and complement proteins.
Humoral immunity allows to distinguishes two groups of foreign substances. it involves <u>B cells</u> and<u> recognize antigens or pathogens in the lymph or blood. </u>
Humoral immunity begins when an antigens bind to B cells. Interleukins or helper T cells provides a secondary signal to the B cells that activates a B cell and allows B cell proliferation. which roduces produce plasma cells. The plasma cell then produces antibodies which are identical to the specific antigen. The antibodies are the released and circulate through the body, binding to antigens. B cells the further produces memory cellss for future immunity.
So, Humoral immunity involves <u>B cells</u> and<u> recognize antigens or pathogens in the lymph or blood.</u>
Answer:
The correct answer is option E. "nucleotides can only be added to an available 3'-OH group on the transcript terminus".
Explanation:
RNA synthesis is catalyzed by an enzyme called RNA polymerase. RNA polymerase always catalyze the synthesis of new RNA from 5' to 3' because nucleotides can only be added to an available 3'-OH group on the transcript terminus. This has been confirmed in labeling experiments with γ-32P substrates which establish the presence of a triphosphate moiety in transcripts with either pppG or pppA.
