Cell Division: Prokaryotic vs. Eukaryotic

Summary

This video script delves into the distinctions between cell division in prokaryotic and eukaryotic cells. Prokaryotic cells, like bacteria, undergo binary fission, a simpler process involving cell elongation, DNA replication, and division without a defined nucleus or organelles. In contrast, eukaryotic cells, found in plants, animals, and fungi, experience mitosis—a more complex process with stages like prophase, metaphase, anaphase, and telophase, where DNA condenses into chromosomes and is organized by spindle fibers. Both processes result in two cells with identical DNA, but mitosis is characterized by the presence of chromosomes and spindles, reflecting the complexity of eukaryotic cells.

Takeaways

• 🧬 Procaryotic cells, like bacteria, are simpler and lack a defined nucleus and organelles, whereas Eukaryotic cells, found in plants, animals, and fungi, are more complex.
• 🔄 Binary fission is the cell division process in procaryotic cells, which is simpler compared to mitosis in eukaryotic cells.
• 📈 In binary fission, the cell first elongates, then the DNA replicates, followed by the division of the cell wall and plasma membrane, and finally, the cell pinches off into two separate cells.
• 🔎 The DNA in procaryotic cells remains disorganized during division, unlike in eukaryotic cells where it condenses into chromosomes.
• 🌐 Mitosis is the process of cell division in eukaryotic cells, involving stages like prophase, metaphase, anaphase, and telophase, which are not present in binary fission.
• 🧬 During mitosis, chromosomes condense, align at the cell's center, separate, and the nuclear membrane reforms around the new nuclei.
• 🌟 Eukaryotic cells have more DNA, which is why the process of mitosis is more complex and involves structures like spindle fibers to organize the DNA.
• 🔑 Both binary fission and mitosis result in the replication of DNA and the division of the cell into two new cells, each with the same DNA.
• 🔍 The key differences between binary fission and mitosis include the presence of chromosomes and spindles in mitosis, which are absent in binary fission.
• 📚 Understanding the similarities and differences between binary fission and mitosis is crucial for comprehending cell division processes and may be a focus in evaluations.

Q & A

What is the main difference between prokaryotic and eukaryotic cells?

Prokaryotic cells, such as bacteria, are simpler and lack a defined nucleus and organelles except for the ribosome. Eukaryotic cells, found in organisms like plants, animals, and fungi, are more complex and have a defined nucleus and various organelles.

What is the process of cell division in prokaryotic cells called?

The process of cell division in prokaryotic cells is called binary fission.

How does the cell prepare for binary fission?

In binary fission, the cell first elongates and replicates its DNA, resulting in two copies of DNA.

What happens during the division phase of binary fission?

During the division phase of binary fission, the cell wall and plasma membrane begin to divide, separating the two copies of DNA into two distinct sections.

How does the cell complete the binary fission process?

The cell wall forms and closes around each section of DNA, and then the two sections pinch off, resulting in two new cells with identical DNA.

What is the term for the structure that separates the two sections of DNA during binary fission?

The term for the structure that separates the two sections of DNA during binary fission is the cross wall.

What is the name of the cell division process in eukaryotic cells?

The name of the cell division process in eukaryotic cells is mitosis.

What is the significance of chromosomes during mitosis in eukaryotic cells?

Chromosomes are the condensed form of DNA during mitosis in eukaryotic cells, which allows for organized and efficient cell division due to the higher amount and complexity of DNA.

What role do spindles play in mitosis?

Spindles are the string-like structures that move chromosomes around during mitosis, generated by the centrosome, and they help in aligning and separating chromosomes.

How does the process of DNA replication differ between binary fission and mitosis?

In both binary fission and mitosis, DNA is replicated to ensure each new cell receives a copy. However, in binary fission, the DNA remains uncondensed, while in mitosis, DNA condenses into chromosomes.

What are the two key similarities between binary fission and mitosis?

The two key similarities between binary fission and mitosis are that DNA is copied in both processes, and the cell divides to form two new cells at the end.

Outlines

00:00

🔬 Cell Division in Prokaryotic vs. Eukaryotic Cells

This video segment introduces the differences in cell division between prokaryotic and eukaryotic cells. Prokaryotic cells, such as bacteria, are simpler and lack a defined nucleus and organelles except for ribosomes. In contrast, eukaryotic cells, found in plants, animals, and fungi, are more complex. The video focuses on eukaryotic cell division but starts with prokaryotic division, specifically binary fission, to highlight the simplicity compared to mitosis in eukaryotes. Binary fission involves cell elongation, DNA replication, division of the cell wall and plasma membrane, and finally, the formation of two separate cells with identical DNA. A transmission electron image illustrates the disorganized appearance of prokaryotic DNA during division. The segment ends with a brief mention of mitosis in eukaryotic cells, noting the more complex process involving visible steps like chromosome formation, alignment, and separation, which are not present in prokaryotic cells.

Keywords

💡Procaryotic cells

Procaryotic cells are simple, single-celled organisms such as bacteria that lack a defined nucleus and membrane-bound organelles, except for the ribosome. In the video, the script explains that these cells undergo a different type of cell division called binary fission, which is simpler compared to the process in eukaryotic cells. The video uses procaryotic cells as a starting point to contrast with eukaryotic cells, highlighting the differences in cell division mechanisms.

💡Eukaryotic cells

Eukaryotic cells are more complex and are found in organisms like plants, animals, and fungi. They contain a defined nucleus and various membrane-bound organelles. The video script emphasizes that eukaryotic cells undergo mitosis, a more complex form of cell division, which is the main focus of the video. The script contrasts eukaryotic cell division with procaryotic cell division to illustrate the increased complexity and organization in eukaryotes.

💡Binary fission

Binary fission is the process of cell division in procaryotic cells. It is described in the video as a simpler process where the cell elongates, DNA is replicated, and then the cell wall and plasma membrane divide, separating the two copies of DNA into two new cells. The script uses the term to highlight the straightforward nature of cell division in procaryotic cells, which lacks the organized steps seen in mitosis.

💡Mitosis

Mitosis is the process of cell division in eukaryotic cells that involves multiple stages, including prophase, metaphase, anaphase, and telophase. The video script explains that mitosis is more complex than binary fission, with visible structures like chromosomes and spindle fibers that organize and separate the genetic material. Mitosis is central to the video's theme, as it is the primary method of cell division in eukaryotic cells and is contrasted with binary fission.

💡Chromosomes

Chromosomes are thread-like structures made of DNA and proteins that carry genetic information. In the context of the video, chromosomes are a key feature of eukaryotic cells during mitosis. The script mentions that in eukaryotic cells, DNA condenses into chromosomes, which is a significant step not present in procaryotic cell division. Chromosomes are essential for the orderly separation of genetic material during cell division.

💡Spindle fibers

Spindle fibers are thread-like structures that play a crucial role in the movement and separation of chromosomes during mitosis in eukaryotic cells. The video script describes how spindle fibers are generated by the centrosome and help in aligning and separating chromosomes. This is a key difference from binary fission, where such organized structures are absent.

💡DNA replication

DNA replication is the process of copying genetic material, which is a necessary step before cell division in both procaryotic and eukaryotic cells. The video script mentions that DNA replication occurs in both binary fission and mitosis, ensuring that each new cell receives a complete set of genetic information. This process is fundamental to the video's discussion of cell division, as it is a common step in both types of cell division.

💡Cell wall

The cell wall is a rigid structure that surrounds and protects cells, particularly in procaryotic cells. In the video script, the cell wall's role in binary fission is highlighted, as it begins to divide and eventually forms a cross wall that separates the two new cells. The cell wall is a defining feature of procaryotic cells and plays a critical role in their division process.

💡Plasma membrane

The plasma membrane is a selectively permeable barrier that surrounds cells and regulates the movement of substances in and out of the cell. In the video, the plasma membrane's division is described as part of the binary fission process in procaryotic cells, where it pinches off to form two separate cells. This term is important for understanding how cell division is accomplished in the absence of a nucleus and other organelles.

💡Cleavage furrow

The cleavage furrow is a constriction that forms in the center of a dividing eukaryotic cell during cytokinesis, eventually pinching the cell into two. The video script uses this term to illustrate the final stages of cell division in eukaryotic cells, where the cell physically separates into two distinct cells. This term is crucial for understanding the physical changes that occur during the end of mitosis.

Highlights

Procaryotic cells, such as bacteria, are simpler and lack a defined nucleus and organelles except for ribosomes.

Eukaryotic cells, found in plants, animals, and fungi, are more complex and have a defined nucleus and various organelles.

Binary fission is the cell division process in procaryotic cells, which is simpler compared to mitosis in eukaryotic cells.

In binary fission, the procaryotic cell first elongates and its DNA is replicated.

The cell wall and plasma membrane then begin to divide, segregating the replicated DNA.

The cell wall forms and closes around the separated DNA sections in procaryotic cells.

The final step in binary fission is the pinching off of the two sections, resulting in two new cells with identical DNA.

Transmission electron images reveal the disorganized appearance of DNA in procaryotic cells during binary fission.

Mitosis is the cell division process in eukaryotic cells, involving more complex steps than binary fission.

During mitosis, eukaryotic cells undergo stages including prophase, metaphase, anaphase, and telophase.

Eukaryotic cells have chromosomes that condense from DNA during cell division, unlike the uncondensed DNA in procaryotic cells.

Spindle fibers, generated by the centrosome, play a crucial role in organizing chromosome separation in mitosis.

In contrast to the organized spindle fibers in mitosis, DNA in procaryotic cells simply moves to the cell poles during binary fission.

Both binary fission and mitosis involve DNA replication and cell division, but the processes differ in complexity and organization.

The video emphasizes the importance of understanding the similarities and differences between binary fission and mitosis for educational evaluations.

Transcripts

this video is about the difference

between cell division in procaryotic and

in eukariotic cells if you remember from

back on the chapter when we were

studying cell types procaryotic cells

are simpler things like bacteria that

don't have a defined nucleus and don't

have defined organel aside from the

ribosome whereas eukaryotic cells are

more complex things like the cells in

plants animals fungus you know things

like that uh for the most part we're

going to be focused on cell division in

eukariotic cells but in order to

appreciate the complexities of this we

have to look at the way it works in

procaryotic cells as well so we'll start

with that um this process that happens

in procaryotic cells is called binary

fision and this is different from the

process of mitosis that we'll be looking

at in eukaryotic cells in that it's a

lot more simplistic so if we just go

through the different steps here the

first thing that happens is the cell

elongates it gets a little bit bigger

and the DNA is replicated which means

that it's copied so we got a new set of

DNA the next thing to happen is that the

cell wall and the plasma membrane begin

to divide so you can see here that the

one copy of DNA is now on the right the

other copy of DNA is on the left uh in

step three the cell wall begins to form

and it completely closes around that

section of DNA so it's now stuck in one

half of the cell and then the last step

these two sections pinch off the cell

sep separate and now at the end we have

two new cells with the exact same DNA in

each one um on the right hand side over

here is a transmission electron image of

this process happening you can see the

DNA still kind of like a clustered mess

and that was one of the things that sort

of defined procaryotic cells they don't

have these organel on the inside of them

to give them structure so it's kind of

disorganized and messy looking the cross

wall is beginning to form which is the

term for like the section that kind of

cuts off the the two sections of DNA one

on each side of the new cell so a binary

fion is very simple the same general

principles are followed here as the r in

mitosis the idea that the DNA is copied

and then eventually you end up with two

separate cells it's just the process in

between it's like all this middle stuff

that's different between the two steps

uh to give you a good appreciation for

this we'll take a look at what happens

in eukariotic cells we're going to spend

a lot of time on this process as we work

our way through the chapter so I'm not

going to get into too many Det details

with you right now but mitosis is the

name for the uh actual steps that look

different inside of the cell during cell

division if you remember from the the

cell division video there's much more to

division than just mitosis but this is

the stuff you can actually see when

you're looking under the microscope you

know during innerphase a lot of things

are happening during SASE the DNA is

copied uh then during prophase you can

actually see the DNA condensed down into

these things called chromosomes so

that's something that didn't happen in

the procaryotic cell the DNA just kind

of stayed this jumbled mess uh the

reason they have to condense down is

eukariotic cells have a lot more DNA

they're much more complicated and in

order to move things through the process

of division in an organized fashion the

DNA has to be condensed down into

chromosomes then they line up in the

middle of the cell during metaphase they

pull apart during anaphase then during

telophase the nuclear membrane starts to

reform around our two uh new nuclei and

then you can see here we get What's

called the cleavage Furrow in between

the two sides of the cell uh that's

eventually going to pinch together in

cyto canis where we eventually have two

new cells at the end so it's the same

general idea we're starting with one

cell DNA gets copied we end up with two

new cells at the end the middle steps

are just much more complicated in

mitosis because eukariotic cells are

more complicated and they have more DNA

to deal

with uh just to compare these two

processes a little bit some of the

differences in mitosis you have

chromosomes whereas in binary fision

what's going on in those procaryotic

cells the DNA is uncondensed the other

thing for mitosis are the spindles those

were the little string-like structures

that were moving the chromosomes around

they're generated by the centreal and

that's what kind of pushes the

chromosomes around during the process of

of cell division in binary fision the

DNA just moves to the poles it moves to

like either sides of the cell and it's

not nearly as organized or as structured

in the way that process is happening

uh final thing is just to talk about

some similarities two things they both

have the DNA is copied in both instances

which makes sense because the new cell

requires that DNA and the cell does

divide at the end although the process

for that happening looks a little bit

different in both of these uh it's good

to know some similarities and

differences for these two that's

probably what you're going to see coming

up on evaluations about this kind of uh

this part of the chapter so as always

thank you for watching and I'll see you

in class