A. nucleus B. mitochondria C. endoplasmic reticulum D. cytoplasm 相关知识点: 试题来源: 解析 A。细胞的结构主要由细胞核决定。细胞核控制着细胞的遗传和代谢活动,对细胞的结构和功能起着关键作用。线粒体主要提供能量,内质网参与蛋白质合成和运输,细胞质是细胞内各种细胞器和物质的载体,但它们都不是决定细胞...
The chromonema is derived by the union of chromosomes in prophase, and during interkinesis the chromosome is represented by a double chain of chromomeres. From the evidence of karyomeres in animal cells, the nucleus is regarded as a compound structure, and it was further suggested that the ...
Chromosomes are the most important parts of the cell nucleus. Each chromosome has two components: 1) an axis formed by protein fibers, and 2) long loops of a molecule called DNA that hang off of the chromosome’s axis. There are 46 chromosomes in each human cell. Each chromosome is plast...
As it was pointed out during the opening lecture of the Workshop, we had several anniversaries in 2003, which are concerned with the cell nucleus. The 50 years of the double helix paper have been celebrated all over the world, but two others are worth mentioning: the paper by Cogliati ...
Nucleus, in biology, a specialized structure occurring in most cells (except bacteria and blue-green algae) and separated from the rest of the cell by a double layer, the nuclear membrane. The nucleus controls and regulates the activities of the cell (e.
Nucleus introduction The nucleus (plural: nuclei) is found in eukaryotic cells. While most cells have a single nucleus, some cell types do not have a nucleus while others have many nuclei. A cell’s nucleus is a membrane-bound organelle that consists of the nuclear envelope, a double membran...
Nucleus introduction The nucleus (plural: nuclei) is found in eukaryotic cells. While most cells have a single nucleus, some cell types do not have a nucleus while others have many nuclei. A cell’s nucleus is a membrane-bound organelle that consists of the nuclear envelope, a do...
Structure and Organization of the NucleusAs the organelle that contains the genetic material of a cell, the nucleus can be described as the command center. As such, the nucleus consists of a number of structured elements that allow it to perform its functions. This section gives focus to the...
Organelle, any of the specialized structures within a cell that perform a specific function (e.g., mitochondria, ribosomes, endoplasmic reticulum). Organelles in unicellular organisms are the equivalent of organs in multicellular organisms. The contracti
When a eukaryotic cell divides, the DNA inside the nucleus does so first, after all of the chromosomes are replicated. This process, calledmitosis, is detailed later. Ribosomes and Protein Synthesis Ribosomes are found in the cytoplasm of both eukaryotic and prokaryotic cells. In eukaryotes they...