Name: interphase and cell growth
Uploaded: 2025-05-22T09:05:54.000Z
Duration: 56 s
Channel: JoVE

في الخلايا حقيقية النواة ، الجزء الأكبر من دورة الخلية هو الطور البيني ، والذي ينقسم إلى ثلاث مراحل ، G1 و S و G2.
 في G1 ، مرحلة الفجوة الأولى ، تنمو الخلية الوليدة التي تم إنشاؤها حديثا في الحجم وتستعد لتكرار الحمض النووي في المرحلة التالية.
الآن ، في S ، مرحلة التوليف ، تقوم الخلايا بتكرار حمضها النووي ، والذي يظل معبأا على شكل كروماتين. تقوم الخلايا أيضا بتكرار الجسيمات المركزية ، وهي الهيكل المنظم للأنابيب الدقيقة التي تشكل جهاز المغزل الانقسامي.
أخيرا ، في G2 ، مرحلة الفجوة الثانية ، تستمر الخلايا في النمو ، وتتكاثر العضيات والبروتينات اللازمة للانقسام وتجديد مخازن الطاقة الخاصة بها. الخلية جاهزة الآن لدخول المرحلة الأولى من الانقسام.

الطور البيني

Interphase

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تحدث دورة الخلية على مدى 24 ساعة تقريبًا (في خلية بشرية نموذجية) وفي مرحلتين متميزتين: الطور البيني، والذي يتضمن ثلاث مراحل من دورة الخلية (G1، S، وG2)، والانقسام المتساو (M). خلال الطور البيني، الذي يستغرق حوالي 95% من مدة دورة الخلية حقيقية النواة، تنمو الخلايا وتضاعف الحمض النووي الخاص بها استعدادًا للانقسام المتساوي.

مراحل الطور البيني

بعد كل فترة من الانقسام المتساوي والانقسام السيتوبلازمي، تدخل الخلايا حقيقية النواة في الطور البيني، حيث تنمو خلالها وتتكاثر حمضها النووي استعدادًا للانقسام المتساوي التالي.

خلال مرحلة G1 (الفجوة 1)، تنمو الخلايا بشكل مستمر وتستعد لـ تضاعف الحمض النووي. خلال هذه المرحلة، تكون الخلايا نشطة في عملية التمثيل الغذائي وتقوم بنسخ العضيات الأساسية و الجزيئات الكيميائية الحيوية، مثل البروتينات.

في مرحلة S (التوليف) اللاحقة من الطور البيني، تقوم الخلايا بمضاعفة الحمض النووي النووي الخاص بها، والذي يظل معبأً في كروماتين شبه مكثف. أثناء الطور S، تقوم الخلايا أيضًا بتكرار الجسم المركزي، وهو هيكل منظم الأنيبيبات الدقيقة يشكل جهاز المغزل الانقسامي. يفصل المغزل الانقسامي الكروموسومات أثناء الانقسام.

في المرحلة G2 (الفجوة 2)، والتي تتبع تركيب الحمض النووي، تستمر الخلايا في النمو وتصنيع البروتينات والعضيات للتحضير للانقسام المتساوي.

في الخلايا البشرية، تمتد المرحلة G1 حوالي 11 ساعة، وتستغرق المرحلة S حوالي 8 ساعات، وتستمر المرحلة G2 حوالي 4 ساعات. خلال G1، تكون الخلايا ثنائية الصيغة الصبغية (2n، زوج من كل كروموسوم). بعد التكرار في الطور S، تزيد الخلايا محتوى الحمض النووي الخاص بها إلى 4n. تبقى الخلايا 4n حتى الانقسام السيتوبلازمي، وعند هذه النقطة يتم تقليل محتوى الحمض النووي الخاص بها إلى 2n .
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تحدث دورة الخلية على مدار 24 ساعة تقريبا (في خلية بشرية نموذجية) وعلى مرحلتين متميزتين: الطور البيني ، والذي يتضمن ثلاث مراحل من ...

Education

JoVE Core

Anatomy and Physiology

التشريح وعلم وظائف الأعضاء

Unit 1

الوحدة الأولى

Essential Cellular Processes

العمليات الخلوية الأساسية

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

interphase and cell growth

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins.

During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division.

Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get ready for mitosis. These steps keep the cell cycle moving in an orderly way.

Interphase and Cell Growth

the central dogma

Central Dogma: DNA to Protein

The central dogma explains how genetic information flows in cells from DNA to RNA to protein. It is a core idea in molecular biology and helps show how genes influence cell function. DNA stores the instructions. During transcription, a cell copies a gene into RNA, which is a related nucleic acid. That RNA message can then be used in translation to build a protein. Proteins carry out many jobs in cells and help determine traits. The central dogma links the genetic code in DNA to the molecules...

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Eukaryotic DNA Copying at the Replication Fork

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RNA Types in Gene Expression

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transcription

Transcription and RNA Synthesis

Transcription is the process of making RNA from a DNA template. It is a key step in gene expression, because cells use the DNA sequence to build an RNA copy that can carry the message forward. During transcription, RNA polymerase binds to DNA and reads one strand as the template. The enzyme links RNA nucleotides together in the correct order to form a growing RNA molecule. This copying step does not make DNA; it produces RNA. The transcript focuses on the central idea of transcription as DNA...

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Translation: mRNA to Protein

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what is the cell cycle?

Cell Cycle Stages in Cell Growth

The cell cycle is the process that controls cell growth and division. It explains how one cell makes two new cells. This process helps cells grow and reproduce.

interphase

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins. During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division. Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get...

mitosis and cytokinesis

Cell Division: Mitosis and Cytokinesis

Cell division depends on mitosis and cytokinesis. Mitosis is the stage when the cell’s nucleus divides and the copied chromosomes are separated into two sets. Cytokinesis is the step that follows and splits the cell into two daughter cells. These two processes work together to make sure each new cell receives genetic material and its own cytoplasm. Mitosis keeps the chromosome sets organized, while cytokinesis finishes the division of the whole cell. Together, they create two separate cells...

the cell cycle control system

Cell Cycle Checkpoints and Cyclin Control

The cell cycle is controlled by checkpoints that help a cell move from one phase to the next and begin mitosis. This control system uses internal regulatory molecules and outside signals to send stop or advance instructions. It makes sure each step is finished before the cell moves forward. Cyclins and cyclin-dependent kinases, or Cdks, are the main regulators of the cell cycle. They act during the G1, G2, and M phases. These regulators work at specific checkpoints to keep cell division...

molecular factors affecting cell division

molecular-factors-affecting-cell-division

Cell Cycle Regulators That Control Division

Cell division is controlled by outside signals and by internal cell cycle regulators. Nearby cell death can encourage division, and human growth hormone (hGH) can also promote it. In contrast, too little hGH or crowded cells can slow or stop division. Inside the cell, regulator molecules help each stage finish correctly before the next stage begins. Some regulators act directly on the cycle, while others affect the activity or production of other regulatory proteins. These molecules can either...

what is meiosis?

Meiosis and the Formation of Gametes

Meiosis is the cell division process that forms gametes, or sex cells. It reduces the chromosome number so offspring can inherit the correct amount of genetic material. This process includes two successive divisions. First, one cell divides, and then the resulting cells divide again. These steps separate the genetic material in a controlled way. Meiosis helps explain how sexual reproduction passes traits from one generation to the next. It is a key topic in high school biology because it...

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Cell Signaling Pathways and Responses

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G Protein-coupled Receptor Signaling

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cellular differentiation

From Stem Cell to Specialized Cells

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key terms and concepts

Learn how interphase supports cell growth, DNA copying, and preparation for mitosis. A clear high school explanation of this key cell cycle stage.

Interphase and Cell Growth | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

Interphase and Cell Growth

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