Study sets, textbooks, questions
Upgrade to remove ads
Mitosis Chapter 7
Terms in this set (31)
What is the function of cell division in one-celled organisms?
Reproduction is the function of cell division in unicellular organisms.
What are the functions (3) of cell division in multicellular organisms?
Mitosis is a way to: growth, cell replacement, build tissues and organs during development and repair damaged tissue.
What is the major advantage of being multicellular?
A multi-cellular organism often has different kinds of cells which are specialized for carrying out certain tasks. Additionally, being multi-cellular increases the capabilities of an organism- a multi-cellular can form organs such as a brain, heart, lungs etc. making a more complex living thing
What are three benefits of being multicellular?
Three benefits of being multicellular are: larger size, longer life, and specialization of cells.
What is cell division in prokaryotic organisms called, and how does it occur?
Binary fission - Reproduction of a prokaryote by division of a cell into two comparable progeny cells.
Prokaryotic cells are simple in structure when compared to eukaryotic cells. They contain non-membranous organelles, lack a cell nucleus, and have a simplistic genome: only one circular chromosome of limited size. Therefore, prokaryotic cell division, a process known as binary fission, is fast. The chromosome is duplicated prior to division. The two copies of the chromosome attach to opposing sides of the cellular membrane. Cytokinesis, the physical separation of the cell
The nucleic acid-protein complex that makes up eukaryotic chromosomes.
• A DNA molecule & attached proteins
• Duplicated in preparation for mitosis
- Stays like this until late in mitosis, sister chromatids
Each of a pair of newly replicate chromatids.
The region where sister chromatids join.
Specialized structure on a centromere to which microtubules attach.
What do the terms diploid and haploid mean?
Diploid (2n): Having a chromosome complement consisting of two copies - homologs - of each chromosome. When cells have two alleles of a gene.
Haploid (n): Having a chromosome component consisting of just one copy of each chromosome. Half of the usual number of chromosomes which gametes have.
What is the term given to the phase of the cell cycle which is "between" cell divisions?
Interphase - In the cell cycle, the period between successive nuclear divisions during which the chromosomes are diffuse and the nuclear envelopes is intact. During interphase the cells is most active in transcribing and translating genetic information.
Here the cell continues to grow and condense so the cell can get ready for replication
What happens in the G1 phase during interphase?
G1 is - In the cell cycle, the gap between the end of mitosis and the onset of the S phase.
The cell experiences growth and last about 10 hours.
Cells increase in size. produce RNA and synthesize protein. G1 checkpoint to make sure cell is ready for DNA synthesis.
What happens during the S phase?
During the S phase, DNA is being duplicated. Before it enters S phase, the DNA only has one chromatid, after S phase, it now has sister chromatids but same number of chromosomes. Last eight hours
Also known as synthesis phase. during this the DNA in the cell copied, so it now has 2 identical protein chains, one for each daughter cell.
What happens during G2 phase?
This is the final stage during interphase that the cell prepares itself before it undergoes mitosis. Basically the same as G1, runs a check known as the G2 checkpoint.
When cells do not divide, in what stage do they remain?
"Some say though that cells that are not dividing remains in G1 or growth phase."
Some cells, like nerve cells never leave G1 and this is sometimes called a G0 state
The G0 phase (referred to the G zero phase) or resting phase is a period in the cell cycle in which cells exist in a quiescent state. G0 phase is viewed as either an extended G1 phase, where the cell is neither dividing nor preparing to divide, or a distinct quiescent stage that occurs outside of the cell cycle
What are the major events of prophase?
1. Chromatin condenses into chromosomes
2. Centrioles move to opposite sides of the cytoplasm.
3. Nuclear membrane and nucleolus disperse.
4. Microtubules assemble and associate with centrioles and chromatids of chromosomes.
What major events are occurring during metaphase of mitosis?
1. Spindle fibers from the centrioles attach to the centromeres of each chromosome.
2. Chromosomes align midway between the centrioles.
What major events are occurring during anaphase of mitosis?
1. Centromeres separate, and chromatids of the chromosomes separate.
2. Spindle fibers shorten and pull these new individual chromosomes toward centrioles.
3. Cytokinesis begins.
What major events are occurring during telophase of mitosis?
1. Chromosomes elongate and form chromatin threads.
2. Nuclear membranes form around each chromosome set.
3. Nucleoli Form.
4. Microtubules break down.
What is the outcome of one mitotic division?
Mitosis results in the production of two genetically identical diploid cells.
2 identical daughter cells identical to the parent cell.
Mitosis - Nuclear division in eukaryotes leading to the formation of two daughter nucleic, each with a chromosome complement identical to that of the original nucleus.
What is cytokinesis, when does it occur?
Cytokinesis, is the division of the cytoplasm of a dividing cell.
Cytokinesis is a cell process in which the cytoplasm is divided in two for daughter cells. Cytokinesis occurs in the late stages of mitosis and meiosis. These are both cell reproduction cycles.
The stage that cytokinesis typically occurs in is late anaphase and end of telophase. This happens during the cell cycle over the life of a single cell.
In what ways is cytokinesis different in plant and animal cells? Animal
- Cleavage furrow (animals) - band of microfilaments
Cytokinesis - In order to make two cells, the cytoplasm has to get divided by having the cell membrane cut the parent cell in two.
Animal cells don't have a cell wall.
Animal cells make a structure called a cleavage furrow.
Animal cells undergo cytokinesis by pinching off along their equator.
The pulling in of this cleavage furrow continues until the deepest parts all touch each other. At that point, when membrane hits membrane, the cell membrane fuses together, separating the two daughter cells.
In what ways is cytokinesis different in plant and animal cells? Plant
- Cleavage furrow (animals) - band of microfilaments
Plant cells have their structural cell wall outside of them-- and need to get cell wall between the two new daughter cells. Plant cells go through cytokinesis by making a structure called a cell plate. Plant cells cannot do the same because of their cell wall. And they have to get new cell wall between the new cells too.
Plant cells send vesicles filled with cell wall material to their equator. When the vesicles reach the equator, they bump into other vesicles and fuse together. This fusion forms a long tube of membrane with cell wall material within it, called the cell plate. As more vesicles go to the equator, the cell plate expands until it bumps into the cell membrane. When it reaches the cell membrane, it fuses with it. This separates the cell in two, with cell wall between them. Later on, the two smaller daughter cells can grow.
What are centrioles and asters, and are they present in plant cells, animal cells, or both?
Centrioles - A paired organelle that helps organize the microtubules in animal and protist cells during nuclear division.
Asters - Asters are radial microtubule arrays, in animal cells, which are located around each pair of centrioles. They appear to be shaped like a star and are involved in the cleavage process of cell division. During cleavage, the cell divides into two cells. In instances where asters are absent from a cell, it will not divide. This cell will form one large cell with two nuclei.
How are identical and fraternal twins formed?
Identical twins are formed when ONE egg gets fertilized and then splits in half after fertilization.. both parts of the egg implant into the uterine wall and develop into identical twins.
Fraternal twins occur when two eggs are released and fertilized by separate sperm... they both implant into the uterine wall and form into two separate babies.
Why are identical twins genetically identical?
The correct term for identical twinning is monozygotic. Monozygotic twins form from a single (mono) fertilized egg (zygote). The zygote splits into two parts after conception, resulting in the development of two individual embryos. Because the two embryos are the result of a single egg/sperm combination, they have the same genetic origins. They have the same DNA.
Why are fraternal twins NOT genetically identical?
Dizygotic twins (often referred to as fraternal), are the result of two eggs fertilized by two separate sperm. Although most women only release a single egg in an ovulation cycle, sometimes multiples eggs are released. Dizygotic twins share about 50% of their genetic traits, the same as any other siblings born at different times.
Why is it possible to clone an animal using the nucleus of a body cell?
The nucleus of a somatic cell is removed and kept, and the host's egg cell nucleus is removed and discarded. Now we have a lone nucleus and an empty (or deprogrammed) egg cell. The lone nucleus is then fused with the 'deprogrammed' egg cell. After being inserted into the egg, the lone (somatic-cell) nucleus is reprogrammed by the host egg cell. The egg, now containing the somatic cell's nucleus, is stimulated with a shock and will begin to divide.
Why is it possible to clone an animal using the nucleus of a body cell? cont...
After many mitotic divisions, this single cell forms a blastocyst (an early stage embryo with about 100 cells) with almost identical DNA to the original organism. The technique of transferring a nucleus from a somatic cell into an egg that produced Dolly was an extension of experiments that had been ongoing for over 40 years. In the simplest terms, the technique used to produce Dolly the sheep - somatic-cell nuclear transplantation cloning - involves removing the nucleus of an egg and replacing it with the diploid nucleus of a somatic cell.
Why it is possible to clone an animal using the nucleus of a body cell?
Nuclear: The nucleus is like the cell's brain. It's an enclosed compartment that contains all the information that cells need to form an organism. This information comes in the form of DNA. It's the differences in our DNA that make each of us unique
Sets found in the same folder
Chapter 9 review questions
Biology 12 - Metabolism and Enzymes
Principles of life Chapter 10
Sets with similar terms
Combo with "Natures miracle workers" and…
Campbell Biology: Ninth Edition - Chapte…
The Cell Cycle, Mitosis, and Meiosis
Chpter10 Biology Section 2
Other sets by this creator
Communication - Final
HLTH 371 Study Guide - Final Exam
Other Quizlet sets
GENE 3200 Exam 2
Unit 2 Concept 1 Study Guide
Fungi, Protozoa and Worms Lecture 7