Professional Courses
Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Categories
Interactive Games
Fun, engaging games to boost memory, math fluency, typing speed, and English skillsβperfect for learners of all ages.
Typing
Memory
Math
English Adventures
Knowledge
Enroll to start learning
Youβve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Introduction to Cytokinesis
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Today, we're discussing cytokinesis, which is the final phase of cell division after karyokinesis. Can anyone tell me why cytokinesis is important?
It divides the cell's cytoplasm into two cells.
Yeah! If it didn't happen, we'd just have a nucleus without a proper cell.
Exactly! Cytokinesis is crucial for ensuring that two functional daughter cells are created. Remember, it follows the separation of chromosomes.
Cytokinesis in Animal Cells
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Letβs delve deeper into how animal cells undergo cytokinesis. Can anyone describe what happens?
I think a groove called a cleavage furrow forms?
And that furrow deepens until the cell splits!
Precisely! The contractile ring made of actin filaments helps form that groove. A good mnemonic to remember this is 'Furrow Fosters Finality'βindicating that the furrow leads to the final split into two cells.
Cytokinesis in Plant Cells
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Now, letβs talk about what happens in plant cells during cytokinesis. What makes it different from animal cells?
They don't form a cleavage furrow, right? They use a cell plate instead.
Yeah! The vesicles fuse to create a new cell wall.
Correct! The origin of the cell plate is essential to remember. An easy mnemonic is 'Plate Makes Plant Parting'βit highlights the plate's role in separating plant cells.
Comparison and Exceptions in Cytokinesis
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Weβve discussed cytokinesis in plants and animals, but are there exceptions?
I read that sometimes karyokinesis doesnβt follow with cytokinesis, especially in some fungi?
Yeah! And that can create multinucleate cells, right?
Great observations! Such cells are called syncytia, and a familiar example is seen in coconut endosperm. Always remember 'Syncytium: Special Scenario' to recall when cytokinesis can be skipped.
Wrap-up and Review
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Before we end todayβs lesson, can anyone summarize what we've learned about cytokinesis?
Cytokinesis is the division of the cytoplasm and forms two new cells.
In animals, it forms a cleavage furrow, while in plants it creates a cell plate.
Excellent! And remember the exceptions where cytokinesis may not occur. This is all essential for understanding the complete process of cell division.
Introduction & Overview
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
Quick Overview
Standard
Cytokinesis occurs after mitosis and is crucial for successfully completing cell division. In animal cells, it involves the formation of a cleavage furrow, while in plant cells, a cell plate is formed. The process ensures that each daughter cell contains the necessary organelles and cytoplasm.
Detailed
Cytokinesis
Cytokinesis is the final stage of cell division in both mitosis and meiosis, following karyokinesis in which the nucleus divides. The primary goal of cytokinesis is to partition the cytoplasm and associated organelles into two distinct daughter cells. This process varies significantly between animal and plant cells.
In animal cells, cytokinesis begins with the formation of a cleavage furrow that encircles the cell and gradually deepens, resulting in the division of cytoplasmic contents. This furrow is facilitated by a structure called the contractile ring, composed primarily of actin filaments, which constricts as the furrow deepens. The cleavage furrow eventually meets at the center, hence achieving the complete separation of the two daughter cells.
Conversely, in plant cells, cytokinesis is distinct due to the presence of a rigid cell wall. Instead of forming a furrow, plant cells develop a cell plate at the center of the cell where vesicles containing cell wall materials fuse. This cell plate expands outward and eventually fuses with the existing cell wall, creating two separate daughter cells. Organelles such as mitochondria and plastids are also distributed between the daughter cells during this process.
In some cases, cytokinesis may not follow karyokinesis, particularly in certain fungi and animal cells, resulting in multinucleate cells known as syncytia. An example of this phenomenon is found in the liquid endosperm of coconuts. Understanding cytokinesis is crucial as it completes the cell division process, ensuring that each daughter cell maintains its genetic material and cell structure.
Youtube Videos
Audio Book
Dive deep into the subject with an immersive audiobook experience.
Definition of Cytokinesis
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
Mitosis accomplishes not only the segregation of duplicated chromosomes into daughter nuclei (karyokinesis), but the cell itself is divided into two daughter cells by the separation of cytoplasm called cytokinesis at the end of which cell division gets completed (Figure 10.2 e).
Detailed Explanation
Cytokinesis is the process that occurs at the end of mitosis. While mitosis deals with the separation of the cell's genetic material into two nuclei, cytokinesis is responsible for dividing the cytoplasm. This is crucial because it ensures that both new daughter cells have the necessary cytoplasm and organelles they need to operate effectively.
Examples & Analogies
You can think of cytokinesis like splitting a pizza after cutting it into slices. Each slice represents a new part of the pizza that needs its own toppings (in this case, organelles). Just as each slice must be complete for someone to enjoy their piece of pizza, each daughter cell must have all its components to function.
Cytokinesis in Animal Cells
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
In an animal cell, this is achieved by the appearance of a furrow in the plasma membrane. The furrow gradually deepens and ultimately joins in the centre dividing the cell cytoplasm into two.
Detailed Explanation
In animal cells, cytokinesis occurs through the formation of a cleavage furrow. As the cell prepares to divide, the membrane begins to pinch inwards at the center. This pinching continues until the membrane separates completely, forming two individual daughter cells. This mechanism is important in animal cells due to their flexible membranes.
Examples & Analogies
Imagine a drawstring bag: when you pull the strings (like the components inside the cell pulling together), the bag closes in at the middle, separating the contents into two halves. This represents how the animal cell divides, with the cleavage furrow acting like the string tightening around the center.
Cytokinesis in Plant Cells
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
Plant cells however, are enclosed by a relatively inextensible cell wall, therefore they undergo cytokinesis by a different mechanism. In plant cells, wall formation starts in the centre of the cell and grows outward to meet the existing lateral walls.
Detailed Explanation
Because plant cells have a rigid cell wall, they cannot simply pinch in half like animal cells. Instead, they form a structure called the cell plate in the middle of the cell. Vesicles that contain the materials for the new wall fuse to form this plate, which then expands outward until it fuses with the existing cell walls, completing the division.
Examples & Analogies
Think of building a fence around a yard. You start at a central point (the cell plate) and build outward towards each edge of the yard (the existing walls of the cell). This method ensures that the new fence not only divides the yard but also integrates with the existing boundaries.
Distribution of Organelles
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
At the time of cytoplasmic division, organelles like mitochondria and plastids get distributed between the two daughter cells.
Detailed Explanation
During cytokinesis, not only is the cytoplasm divided, but important cellular organelles are shared between the two new cells. Mitochondria and plastids are essential for energy production and photosynthesis, respectively, so it is crucial that both daughter cells receive a fair distribution of these components to function properly.
Examples & Analogies
Imagine giving out supplies to two different classrooms. Just like each class needs markers and paper to function well, each new cell needs organelles to perform its essential roles. Ensuring both classrooms receive an adequate amount is like ensuring both daughter cells receive the necessary organelles.
Multinucleate Conditions
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
In some organisms karyokinesis is not followed by cytokinesis as a result of which multinucleate condition arises leading to the formation of syncytium (e.g., liquid endosperm in coconut).
Detailed Explanation
In certain scenarios, after the nucleus divides (karyokinesis), the cytoplasm does not split, resulting in a cell with multiple nuclei. This condition is seen in some types of fungi and the liquid endosperm of coconut, where it is beneficial for the production of large amounts of nutrients.
Examples & Analogies
Think of a large office building where multiple departments (nuclei) share the same physical space (cytoplasm) without walls separating them. This can enhance communication and resource sharing, just like multinucleate cells can share resources more efficiently than separate cells.
Definitions & Key Concepts
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
-
Cytokinesis: The process that divides the cytoplasm into two daughter cells after karyokinesis.
-
Cleavage Furrow: The mechanism of cytokinesis in animal cells involving pinching inwards.
-
Cell Plate: The structure that forms during cytokinesis in plant cells, facilitating cell wall formation.
Examples & Real-Life Applications
See how the concepts apply in real-world scenarios to understand their practical implications.
Examples
-
In animal cells, cytokinesis often results in two daughter cells through the formation of a cleavage furrow.
-
In plant cells, a cell plate forms and expands outwards, resulting in the creation of a new cell wall.
Memory Aids
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
π΅ Rhymes Time
-
Cytokinesis, itβs quite the show, making two cells, watch them grow!
π Fascinating Stories
-
Once there was a big cell who wanted to split into two. With a little help from a furrow, the big cell turned into two little cells, each with their own fun adventures!
π§ Other Memory Gems
-
Furrow Fosters Finality: Remember that in animal cells, cytokinesis forms a cleavage furrow.
π― Super Acronyms
CYTO
- C: for Cleavage furrow in animals
- Y: for Yes
- cytoplasm is divided
- T: for Two cells created
- O: for Organelles need distribution.
Flash Cards
Review key concepts with flashcards.
Glossary of Terms
Review the Definitions for terms.
-
Term: Cytokinesis
Definition:
The process of cytoplasmic division that follows karyokinesis, resulting in two separate daughter cells.
-
Term: Karyokinesis
Definition:
The division of a cell's nucleus during cell division.
-
Term: Cleavage Furrow
Definition:
The indentation that begins the division of the cytoplasm in animal cells.
-
Term: Cell Plate
Definition:
A structure that forms in the middle of a plant cell during cytokinesis, leading to the separation of the daughter cells.
-
Term: Syncytium
Definition:
A multinucleate cell that can arise from a failure of cytokinesis.