Ch. 5 Bio
prophase
DNA and proteins condense into tightly coiled chromosomes, the nuclear envelope breaks down, centrioles begin to move to opposite poles, and spindle fibers form.
How do prophase and telophase differ?
Prophase and telophase are different, because prophase is the first stage of mitosis where the nuclear envelope breaks down, while telophase is the final stage of mitosis where the nuclear membrane forms.
cell diffrentiation
The process by which a cell become specialized for specific structure or function during multicellular development
How does mitosis differ from binary fission?
The processes of binary fission, and mitosis are similar, but they have major differences when it comes to prokaryotic cells. Because prokaryotic do not have a nucleus, spindle fibers, and contain less DNA than eukaryotes, binary fission is a faster process. In binary fission the prokaryotes are copied, and then attach to the cell membrane. When the cell has grown large enough the duplicated chromosomes separate, and the cell undergoes cytokinesis. Based on this, it is obvious binary fission is much faster, and since the cell is more simple it does not undergo as many processes as in mitosis.
asexual reproduction
The production of offspring from a single parent and does not involve the joining or gametes
What is the name of the stage in which the nucleus divides?
The stage in which the nucleus of a cell divides is called mitosis. The entire duration of mitosis includes mitosis and cytokinesis, however the splitting of the nucleus is mitosis.
List and describe the job of two important internal factors.
Two important internal factors include kinases and cyclins. Kinases are enzymes that transfer phosphate groups from one molecule to another in order to increase energy or change a molecule. Cyclins are another internal factor that activate the kinases. Both of these factors help a cell advance from one stage of the cell cycle to another.
anaphase
chromatids separate to opposite sides of the cell, cytokinesis begins in late parts of this
histones
a group of proteins associated with chromosomes: DNA wraps around this
centromere
a region of dense chromosomes that hold chromatids together
gametes
eggs and sperm cells
organs
groups of tissues that work together to perform specific functions or related functions
vegetative reproduction
involves the modification of the stem or underground structures of the parent organism
telophase
nuclear membranes start to form, chromosomes uncoil, and spindle fibers fall apart
chromatid
one half of a duplicated chromosome
chromosome
one long continuous thread of DNA that consists of numerous genes along with regulatory information
organ systems
organs that carry out similar functions
metaphase
spindle fibers attach to each chromosome, the align the chromosomes along the cell equator
totipotent
stem cells can grow into another type of cell only fertilize eggs in cells produced by the first few divisions of an embryo are this
pulripotent
stem cells can grow into any type of cell except for totipotent stem cells
Multi potent
stem cells can grow only into cells of a closely related cell family
carcinogen
substance substances known to produce or promote the development of cancer
chromatin
the complex of proteins and DNA that make up the chromosome
mitosis
the division of the cell nucleus and its contents
telomeres
the ends of DNA molecules that are made of repeating nucleotides that do not form genes
cytokinesis
the process that divides the cell cytoplasm
cell cycle
the regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells
List the job of a growth factor and give an example.
A growth factor is a very important part of cell growth. Growth factors are a broad group of proteins, whose job is to stimulate cell growth. An example of a growth factor are platelets. Platelets are fragments of bone marrow cells that trigger the growth of certain cells in attempt to stop bleeding by forming clots.
fragmentation
A parent organism splits into pieces each of which can grow into a new organism
apoptosis
A program cell death; occurs when signals activate self-destructive genes
budding
A small projection grows on the surface of the parent organism forming a separate new individual
What are stem cells?
A stem cell is a unique type of body cell that can divide and renew themselves for log periods of time, remain undifferentiated in form and differentiate into a variety of specialized cell types.
malignant
A tumor in which cancer cells can break away or meta-size from the tumor
benign
A tumor in which cancer cells remain clustered together in this case the tumor is relatively harmless and can be cured
stem cells
A unique type of body cell that can divide themselves for long periods of time remain undifferentiated in form and differentiate into a variety of specialized cell types
What is the difference between adult stem cells and embryonic stem cells?
Adult stem cells, and embryonic stem cells are two very different types of cells. Adult stem cells, or somatic stem cells, are found all over the body. Embryonic stem cells are found in embryos. The major difference between the two is that embryonic stem cells are pluripotent meaning they can form 200 body cells, however adult stem cells can only form certain other cells. Also, adult stem cells contain more DNA abnormalities, and are less in number.
What is apoptosis and describe is role during human embryonic development.
Apoptosis is a programmed cell death, that is put into action when self-destructive
Why are daughter cells genetically identical to each other and the original cell?
Daughter cells are genetically identical to each other as well as the original cell, because they have the same DNA. The original cells DNA was copied to form the other daughter cells, which is why they are identical.
During which stage of the cell cycle is DNA copied?
During the synthesis stage of interphase in the cell cycle, DNA is copied.
Where do you think G0 would fit into the cell diagram?
GO is a stage of the cell cycle in cells that are unlikely to divide, but still continue to carry out normal cell functions and processes.
Briefly explain why cutting a flatworm into pieces would not kill it.
If a flatworm was cut to pieces, it would not die, because flatworm reproduce though mitosis. To be more specific, flatworms reproduce through fragmentation. This means when a flatworm is split more organisms can be grown from these pieces.
Why are malignant tumors harmful?
Malignant tumors are very harmful due to the spreading of its cells. Because cancer cells can metasize from malignant tumors, they can harm other parts of the body.
What is the name of the stage in which the cytoplasm divides?
Mitosis consists of two processes, mitosis and cytokinesis. Cytokinesis is the division of the cytoplasm within the cell.
List and describe the stages of the division of the nucleus (mitosis).
Mitosis, or the division of the nucleus, occurs in four stages. The stages consist of prophase, metaphase, anaphase, and telophase. The first stage, prophase is when chromatin condenses into chromatids, the nuclear envelope breaks down, the nucleolus disappears, centrosomes and centrioles move to opposite sides of the cell, and the microtubules radiate towards the center of the cell.
growth factors
A broad group of proteins that stimulate cell division; these bind to receptors that activate genes to trigger so growth
What would a cell look like if you treated cells with a chemical to block cytokinesis? (What would a cell look like right after mitosis, before cytosis?)
A cell that has undergone mitosis, but has yet to go through cytosis, would have two nucleuses is and double the amount of cytoplasm.
cancer
A common name for a class of diseases characterized by uncontrolled cell division
tissues
A group of cells that work together to perform a similar function
How do cancer cells differ from healthy cells?
Cancer cells differ from healthy cells, because cancer cells continue to grow and divide even after they are completely surrounded by other cells. Another major difference is that cancer cells have the ability to divide without growth factors that are required for division in healthy cells.
What is a carcinogen and give examples.
Carcinogens are substances that may induce the development of cancer cells in organisms. Carcinogens are very common in everyday life. Examples of carcinogens would include tobacco smoke, air pollutants, and even excessive exposure to sunlight can cause cancer.
Why is cell differentiation an important part of a multicellular organism?
Cell differentiation is important to multicellular organisms, because multicellular organisms need many different functions. Cell differentiation helps with this, because it allows cells to have specific structures, and carry out those functions.
How are cells, tissues, organs and organ systems related? Give an example.
Cells, tissues, organs, and organ systems are all related, because they are all groups of specialized cells that perform certain functions. Tissues are groups of cells, while organs are groups of tissue, and organ systems are groups of organs.
What limits the maximum size of a cell? Describe why it is better for a cell to have a larger surface area to volume ratio?
How small or large a cell can become depends on its ability to function at those sizes. For instance, if a cell were too small it's organelles wouldn't fit within the membrane, and the cell would die. Cells can also be too big to function. When a cells volume increases the surface area may become too small to properly exchange materials. This is why it's better for a cell to have a large surface area to volume ratio.
Describe the difference between malignant tumor vs a benign tumor.
In cancer cells, tow different types of tumors can form. The first kind, an benign tumor, is where the cancer cells remain in certain clusters, which make them harmless and easily cured. The second type is a malignant tumor, which means the cancer cells metasize, or move away from the tumor to other parts of the body.
What role does the location of a cell play in cell differentiation?
In cell differentiation a cells location is vital to its structure. Thats because a cells location within the embryo determines how it will differentiate, which determines its structure and functions.
What is the difference between internal regulation factor and an external factor?
In cells internal and external factors regulate the cell cycle. The difference between these factors are self explanatory. External factors are messages that come from outside the cell, this includes messages from nearby cells or other distant parts of the organisms body.
How does communication between cells help maintain homeostasis?
In cells, communication is important to maintaining homeostasis. Groups of cells like tissues called organs, and groups of organs called organ systems perform specific functions that help maintain certain levels and conditions of an organism.
How does an organism benefit from reproducing asexually and sexually?
Some organisms can reproduce asexual, and sexually. This can be extremely beneficial to the organisms, because if the organism splits it can reproduce through mitotic reproduction, but it can also reproduce sexually which gives it a genetic variation.
Which stages of the cell cycle generally require about the same amount of time in all human cells?
The amount of time it takes for cells to undergo synthesis, gap two, and mitosis generally takes the same amount of time in human cells.
binary fission
The asexual reproduction of the single celled organism by division into two roughly equal parts
meta-size
The breakaway or from cancer cells into other parts of the body
Describe a disadvantage of asexual reproduction.
Unlike sexual reproduction, asexual reproduction produces genetically identical offspring meaning those organisms lack genetic diversity. This has a major negative impact on those organisms, because if one important trait is missing the entire population could die off.
