Unit 7 Lesson 5: Mitosis and Genetic information

Question 1

Where do most complex organisms descend from

Answer 1

Complex organisms usually descend from two parents, and their genetic information is inherited from both. This genetic information is stored in the chromosomes passed down to them. A fertilized egg will continue to grow and develop using mitosis.

Question 2

What does Mitotic cell division produce

Answer 2

. Mitotic cell division produces two genetically identical daughter cells from one parent cell (like a fertilized egg). These daughter cells receive identical genetic information from a parent cell during mitosis.

Question 3

What does it mean for something to be genetically identical

Answer 3

If a cell or organism’s genetic material is an exact copy of the parent cell or organism’s genetic material, the cell or organism is genetically identical

Question 4

What is Gene expression, what does it produce

Answer 4

t gene expression is the process in which instructions (arrangements and types of molecules) in DNA are used to produce a protein or other functional product.

Question 5

Wh

What is the imporenace of protein

Answer 5

Protein is important for the structure and function of body tissue.

Question 6

Depedning on what can two cells may be genetically identical while possessing different attributes.

Answer 6

Depending on gene expression, two cells may be genetically identical while possessing different attributes.

Question 7

What kind of organism reproduce by mitosis

Answer 7

These organisms, which include yeast, phytoplankton, zooplankton, and protozoans, reproduce by mitosis.

Question 8

eukaryotes vs prokaryotes

Answer 8

Organisms that contain chromosomes within the nuclei of their cells are called eukaryotes. This distinguishes them from prokaryotes—single-celled organisms such as bacteria that do not have a cell nucleus.

Question 9

Does mitosis happen in all eukaryotes

Answer 9

Mitosis is a part of the cell cycle that happens in all eukaryotes.

Question 10

In what way is mitosis closely controlled

Answer 10

During mitosis, a single cell divides, producing two identical daughter cells. Because the process of mitosis contains many checkpoints, genetic information is closely controlled, ensuring that daughter cells contain identical copies.

Question 11

Mutilcellur use for mitosis vs unicellular usage

Answer 11

Multicellular eukaryotes use mitotic division for growth, repair, and replacement of worn-out cells. For a unicellular eukaryote, cellular division through mitosis produces a whole new organism.

Question 12

Mitosis is part of which cycle

Answer 12

cellcycle

Question 13

The cell cycle happens in ? distinct stages

Answer 13

2

Question 14

What happens to a cell during interphase

Answer 14

. During interphase, the cell grows and duplicates its DNA to prepare for mitosis

Question 15

What checkpoints does the interphase go through

Answer 15

During interphase, the cell grows and duplicates its DNA to prepare for mitosis. As it grows, the cell passes two checkpoints to ensure that the conditions for replication are correct.

Question 16

Sometimes a cell will not pass a checkpoint. Why is that?

Answer 16

If the cell detects that DNA replication is not perfect or that the DNA has somehow become damaged, it halts the cycle.

Question 17

What happens when a cell reaches a checkpoint

Answer 17

The cell may rest or repeat the stage.

Question 18

What happens when all checkpoints are passed

Answer 18

When all checkpoints are passed, mitosis happens in five phases.

Question 19

The first stage is called prophase. What happens during prophase

Answer 19

During prophase, the protective membrane around the parent cell’s nucleus dissolves. The mitotic spindle is formed, and the chromosomes condense.

Question 20

What happens in the second stage of metaphase

Answer 20

the replicating chromosomes line up in the center of the cell. The mitotic spindle from each side attaches to a chromosome and checks that each chromosome pair is being pulled with equal force to each end of the cell, like a game of tug-of-war. When the checkpoint is passed, anaphase begins.

Question 21

What happens in the thrid stage anaphase

Answer 21

During anaphase, microtubules pull the chromosomes apart, separating them into identical sister chromatids. The pairs of new chromosomes then begin to move away from one another to opposite sides of the cell.

Question 22

What happens in the foruth stage Telephase

Answer 22

Telophase occurs directly after anaphase, after each pair of sister chromatids has finished moving to opposite sides of the cell. In this stage, two new nuclei, one for each set of chromosomes, are formed and grow their protective membranes.

Question 23

What happens in the fifth stage Cytokinesis

Answer 23

During cytokinesis, the cytoplasm divides to make two cells, and the two cells pull apart. The finished process produces two cells where there had previously only been one.

Question 24

When can Cytokinesis being

Answer 24

Cytokinesis can begin in anaphase or telophase but will always conclude during telophase .

Question 25

What happens to the daugther cells after cytokinesis

Answer 25

After cytokinesis, the daughter cells enter interphase to grow, pass checks, and prepare for another replication.

Question 26

Mitosis allows multicellular organisms to grow in size and complexity, compare this to what mitosis allows a unicellular organims to do

Answer 26

Mitosis allows multicellular organisms to grow in size and complexity, but a unicellular organism will never contain more than one cell.

Question 27

how many hours can mitotic replication last

Answer 27

The process of mitotic replication, including interphase, may last more than 24 hours.

Question 28

How do prokaryotes reproduce

Answer 28

Prokaryotes, which have a relatively simpler cell structure, reproduce by binary fission.

Question 29

binary fission

Answer 29

a type of asexual reproduction in which a fully grown parent cell separates into two cells

Question 30

How long cna binary fisson take

Answer 30

. Fission can take as little as 20 minutes to complete.

Question 31

What allows prokaryotes to reporduce faster than eukaryotes? How contorled is the process of binary fisson

Answer 31

Fission can take as little as 20 minutes to complete. This allows them to replicate much faster than eukaryotes, but their replication is much less controlled. In binary fission, copying errors are common. Such errors can be lethal to proliferating cells.

Question 32

what prevents copying errors in singe-celled eukaryotes

Answer 32

Single-celled eukaryotes have many controls, including more checkpoints in the cell cycle. This helps to prevent copying errors.

Question 33

A eukaryotic cell’s complex structure is itself an advantage. Elaborate

Answer 33

Cell membranes protect eukaryotes, and their mitochondria provide an energy advantage that allows the cells to grow much larger than their prokaryotic counterparts.

Question 34

What do larger cells require to prevent errors

Answer 34

Larger cells require more controlled growth in order to prevent errors.

Question 35

What is the role of mitosis

Answer 35

Mitosis regulates cell growth, producing more successful organisms.

Question 36

How does the function of mitosis differ between unicellular and multicellular organisms?

Answer 36

In unicellular organisms, mitosis is the means by which the organism reproduces. In multicellular organisms, mitosis begins after meiotic reproduction in the fertilized egg. It allows growth, repair, and replacement of cells.

Question 37

Unicellular eukaryotes use mitosis for growth and repair.
True or false

Answer 37

false; Multicellular eukaryotes use mitosis for growth and repair.

Question 38

Eukaryotes pass two checkpoints before entering mitosis. What advantage do checkpoints provide in multicellular replication?

Answer 38

Checkpoints make sure the DNA is being replicated exactly, and make sure the daughter cells are identical from the parent cell.

Question 39

Why does reproduction take longer for an amoeba (an eukaryotic cell) than for a bacterium (a prokaryotic cell)?

Answer 39

An amoeba is a eukaryote, which reproduces through mitosis. Bacteria, such as prokaryotes, reproduce by binary fission. Eukaryotes, which have distinct nuclei and organelles, are more complex organisms than prokaryotes. Mitosis takes longer than fission because it contains more phases and checkpoints.

Question 40

How are the two daughter cells from a parent cell genetically identical?

Answer 40

A daughter cell’s chromosomes are exact copies of its parent cell, so all of its genetic information is identical to the genetic information of the parent cell. In a multicellular organism, however, a daughter cell’s function may be very different from the function of a parent cell, depending on its gene expression.

Question 41

What is archaeon

Answer 41

An archaeon is a kind of single-celled organism

Question 42

Prometheoarchaeum syntrophicum

Answer 42

cientists cultured the strange archaeon in the lab and studied its biology. They named the organism Prometheoarchaeum syntrophicum after the Greek god who created humans and stole fire.

Question 43

What does Prometheoarchaeum syntrophicum have to do with mitosis?

Answer 43

There is a hypothesis that eukaryotes arose from an archaeon that was invaded by another organism.

Question 44

What is an endosymbiont

Answer 44

The invading organism is called an endosymbiont.

Question 45

What kind of symbiosis is a endosymbiois

Answer 45

Endosymbiosis is a kind of symbiosis where one organism lives inside another. The two organisms function as one, both benefitting from the arrangement.

Question 46

Scientists believe that this theoretical endosymbiont was the ancestor of today’s mitochondria. What endosymbiont?

Answer 46

Prometheoarchaeum syntrophicum

Question 47

Scientists believe that this theoretical endosymbiont was the ancestor of today’s mitochondria. Elabbroate

Answer 47

The hypothesis is that the symbiont behaved like mitochondria; that would give the ancestors of all eukaryotes the energy to evolve into complex organisms. Until Prometheoarchaeum syntrophicum, though, no one had ever seen such a relationship.

Question 48

What is promethoarchen like

Answer 48

Unlike most archaeonsPrometheoarchaeum possesses distinct cell membranes and has long tentacles that extend from its body. Studying Prometheoarchaeum as it grew in the lab, researchers watched it use those tentacles to capture a bacterium. The archaeon then incorporated the bacterium into its own cell structure.

Question 49

Studying Prometheoarchaeum as it grew in the lab, researchers watched it use those tentacles to capture a bacterium. The archaeon then incorporated the bacterium into its own cell structure. What happend next

Answer 49

The archaeon and the bacterium began exchanging peptides and hydrogen. Even more important, Prometheoarchaeum syntrophicum, with its bacterial symbiont, began to degrade methane anaerobically.
Respiration is a process that provides energy. Anaerobic respiration is respiration that takes place in the absence of oxygen. Prokaryotes, who do not respire, cannot make enough energy to evolve past the unicellular stage.

Question 50

realtionshp between respiration and promethoarchaeum

Answer 50

Respiration gave Prometheoarchaeum syntrophicum enough energy to grow larger and to reproduce much more slowly. Having enough energy to support a slow cell cycle is one of the features of mitosis. The bacteria had changed everything.

Question 51

Based on your reading about Prometheoarchaeum syntrophicum, how do you think cells developed the ability to replicate by mitosis?

Answer 51

Mitosis is a slower process of replication than the ones used by prokaryotes. Growth takes time. Since eukaryotic cells can grow much larger than prokaryotes, a long cell cycle gives them more time to reach their full size.

Question 52

Mitosis requires more energy than binary fission. What advantages does mitosis give to a unicellular organism?

Answer 52

Mitotic checkpoints ensure that a cell’s DNA is copied perfectly. Therefore, when a cell replicates, it does so with few errors. Fewer errors mean the cell replication is more often successful, and this, in turn, means that cell replication does not need to be as fast to remain competitive. Slower replication allows for a longer growth cycle, which makes a larger, stronger organism.

Question 53

Prometheoarchaeum’s large size and slow growth are dependent on its symbiotic bacteria. What advantage would it give the archaeon to develop a cell nucleus?

Answer 53

The membrane around a cell’s nucleus protects it from invasion or damage and keeps its genetic information safe. Based on the behavior of mitochondria, developing a nucleus with a membrane could protect both the archaeon’s chromosomes and the DNA of its symbiont bacterium. Since the nuclear membrane dissolves only during prophase, the bacterium’s DNA, like the archaeon’s, could be more easily regulated.