Cell Biology. the first stage of mitosis or meiosis in eukaryotic cell division, during which the nuclear envelope breaks down and strands of chromatin form into chromosomes.
the first stage of mitosis, during which the nuclear membrane disappears and the nuclear material resolves itself into chromosomes See also metaphase, anaphase, telophase
the first stage of meiosis, divided into leptotene, zygotene, pachytene, diplotene, and diakinesis phases
prophase pro·phase (prō’fāz’)
The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell.
The first stage of meiosis, during which the DNA replicates, homologous chromosomes undergo synapsis, chiasmata form, and the chromosomes contract.
pro·pha’sic (-fā’zĭk) adj.
The first stage in the process of mitosis. Before prophase begins, the chromosomes duplicate to form two long, thin strands called chromatids. During prophase itself, the chromatids condense and thicken to form distinct bodies. Chromatids making up a single chromosome are joined at the middle in an area called the centromere. The membrane surrounding the nucleus disappears, and the spindle begins to form. In prophase and the later stages of mitosis until separation of the individual chromatids during anaphase, each chromosome consists of two chromatids, and each chromatid contains a complete copy of the genetic information belonging to the chromosome. For example, human beings have 23 pairs of chromosomes in all somatic cells, or 46 chromosomes in total. At the end of prophase, each of these 46 chromosomes contains two identical chromatids.
One of the two stages in meiosis that resemble prophase in mitosis. However, there are important distinctions between prophase of mitosis and prophase of meiosis. The prophase of meiosis occurring during the first meiotic division of the cell is usually called prophase I. In prophase I of meiosis, pairs of homologous chromosomes intertwine and the process called crossing over occurs as chromatids from homologous pairs of chromosomes swap genetic information. This process creates genetic diversity among the gametes formed through meiosis. In mitosis, by contrast, pairs of homologous chromosomes remain separate and there is no crossing over, since the purpose of mitosis is to produce cells with identical genetic material rather than gametes. At the beginning of prophase II of meiosis, which occurs after telophase during the first meiotic division, the chromosomes of each daughter cell are grouped together in a mass. During prophase II, the individual chromosomes of the daughter cells become distinct again and begin to prepare for the second meiotic division. If a membrane has formed around the chromosomes at the end of the first division, it disappears during prophase II. See more at meiosis, mitosis.
- Prophecies of habakkuk
were probably written about B.C. 650-627, or, as some think, a few years later. This book consists of three chapters, the contents of which are thus comprehensively described: “When the prophet in spirit saw the formidable power of the Chaldeans approaching and menacing his land, and saw the great evils they would cause in Judea, […]
- Prophecies of hosea
This book stands first in order among the “Minor Prophets.” “The probable cause of the location of Hosea may be the thoroughly national character of his oracles, their length, their earnest tone, and vivid representations.” This was the longest of the prophetic books written before the Captivity. Hosea prophesied in a dark and melancholy period […]
- Prophecies of malachi
The contents of the book are comprised in four chapters. In the Hebrew text the third and fourth chapters (of the A.V.) form but one. The whole consists of three sections, preceded by an introduction (Mal. 1:1-5), in which the prophet reminds Israel of Jehovah’s love to them. The first section (1:6-2:9) contains a stern […]
noun, plural prophecies. 1. the foretelling or prediction of what is to come. 2. something that is declared by a prophet, especially a divinely inspired prediction, instruction, or exhortation. 3. a divinely inspired utterance or revelation: oracular prophecies. 4. the action, function, or faculty of a prophet. noun (pl) -cies 1. a message of divine […]
verb (used with object), prophesied, prophesying. 1. to foretell or predict. 2. to indicate beforehand. 3. to declare or foretell by or as if by divine inspiration. 4. to utter in prophecy or as a prophet. verb (used without object), prophesied, prophesying. 5. to make predictions. 6. to make inspired declarations of what is to […]