Science Chapter 3
chromosome
the physical structure in a cell that contains the cell's genetic material
double helix
DNA is twisted in what shape? ______ ______
Yes
Do prokaryotic cells undergo cytokinesis?
No (they have no nucleus)
Do prokaryotic cells undergo mitosis?
No
Does cell division usually produce offspring in multicellular organisms?
a mass of loose strands
During most of a cell's life, DNA is in what form?
Cell division in multicellular organisms has three functions - growth, repair, and development. A human being begins as a single-celled zygote, but has trillions of cells a few years later. This is accomplished through cell division. If our cells did not divide, we would remain single-celled our entire lives. Our trillions of cells are not identical; we have skin cells, muscle cells, brain cells, and many more. When cells divide, they specialize into certain types. Our complexity stems from the many different types of cells we have; we have a brain to think, muscles to move, etc. If we injure ourselves, a scab forms quickly; the cells surrounding the cut divide rapidly, forming a scab.
Essay Question #1: discuss the three functions of cell division in multicellular organisms.
Asexually reproducing eukaryotes and prokaryotes do so in four different ways: binary fission, cell division with mitosis and cytokinesis, budding, and regeneration. Binary fission, which occurs only in unicellular prokaryotes, is a simple replication of the DNA and splitting of the cell. Cell division with mitosis and cytokinesis is only used by unicellular eukaryotes. The organisms follow the same process that the cells in our body do; they replicate and separate the chromosomes and divide the cytoplasm. Some unicellular and multicellular eukaryotes reproduce by budding, in which small outgrowths form on the outside of an organism.The bud either grows until a certain point and then breaks free, or remains on the parents organism. Lastly, regeneration is a healing process in which lost body parts are replaced. However, some animals regenerate a new organism. For example, a separated body part of a sea star can grow to an entirely new organism.
Essay Question #2: discuss the four different types of asexual reproduction.
muscle, skin, brain, throat, etc. cell
Give an example of a type of specialized cell in a human.
one parent in asexual two parents in sexual
How are the parent organisms different in asexual vs. sexual reproduction?
offspring genetically identical to parent in asexual, genetically different in sexual
How do the offspring differ in asexual vs. sexual reproduction?
cell division
How do unicellular organisms reproduce/
binary fission
How do unicellular prokaryotes reproduce?
It is tightly wrapped( like yarn around craft sticks) into a condensed chromosome form.
How does DNA fit inside the nucleus?
The cell undergoes mitosis and cytokinesis
How does cell division (reproduction) occur in unicellular eukaryotes?
46
How many chromosomes do humans have?
skin cell
If a skin cell divides, what type of cell are the daughter cells?
proteins
In a chromosome, what does the DNA wrap around?
fiber ring contracts
In animal cell cytokinesis, a ________ forms in the center of the cell. It _____, which pulls the membrane inward until the the cell is pinched into two daughter cells.
a
Regeneration is usually: a) used for healing b) a form of reproduction c) a part of a life cycle
The sea star would grow a new limb. In some sea stars, that limb would grow into a new organism.
Suppose a sea star loses a limb. What would happen to that sea star? What would also happen in a few species of sea stars?
T
T/F: A baby has less cells than an adult,
F
T/F: A cell's DNA is always in chromosome form.
F
T/F: A skin cell on your hand has probably been there for your entire life.
T
T/F: All prokaryotes reproduce asexually.
F
T/F: At the end of mitosis, the daughter cells are completely separated.
F
T/F: Cell division is not involved in sexual reproduction.
T
T/F: Cytokinesis differs in plant and animal cells
F
T/F: Cytokinesis occurs in mitosis.
F
T/F: DNA is replicated in cell division.
F
T/F: Daughter cells will never be the same size as their parent.
F
T/F: Each daughter cell receives a 3/4 set of DNA, which will later grow to a full size.
T
T/F: Each daughter cell receives a complete set of DNA
T
T/F: If you could look at it under a microscope, a skin cell would look different than a muscle cell.
F
T/F: Mitosis differs in plant and animal cells
T
T/F: Only eukaryotes reproduce by budding.
F
T/F: Only multicellular organisms reproduce by budding.
F
T/F: Organelles are duplicated right before cytokinesis.
T
T/F: The cells resulting from cell division are identical
T
T/F: The size of an organism does not affect the size of its cells (e.g. A lion will have about the same size cell as a rat)
F
T/F: You might have a different amount of chromosomes than your sibling.
diversity
The combining of genes in sexual reproduction has resulted in much of the ______ of life on Earth.
Cytokinesis
The division of the parent cell's cytoplasm
chromosomes
The genetic material of eukaryotic cells in organised in ____________-
Interphase
The newly formed daughter cells are in what phase?
Cell division
The nucleus of a cell divides in which phase of the cell cycle?
life cycle
The process in which living things grow, reproduce, and die
reproduce
Unicellular organisms _______ through cell division.
growth, development, repair, and is involved in reproduction
What are the functions of cell division in multicellular organisms?
growth, repair, development, reproduction
What are the functions of cell division in multicellular organisms?
centromere
What are the two chromatids held together by?
interphase and cell division
What are the two main phases of the cell cycle?
Mitosis and cytokinesis
What are the two parts in cell division?
prokaryotic asexual reproduction and eukaryotic asexual reproduction
What are the two ways of asexual reproduction?
budding and regeneration
What are two ways multicellular eukaryotes reproduce?
cell division and budding
What are two ways unicellular eukaryotes reproduce?
Growth, normal life activities such as transportation of materials, DNA replication, and organelle duplication
What cell processes occur in interphase?
Cytoplasm divides
What happens in cytokinesis?
It is replicated, and two replicated DNA strands, called chromatids, join together by a centromere.
What happens to the loose mass of DNA in a cell
interphase
What is the longest phase of the cell cycle?
Prophase, metaphase, anaphase, telophase
What is the order of the four parts of mitosis?
Cytokinesis
What occurs immediately after mitosis?
cell division
What process causes a scab to form after a cut?
the spindle fibers
What structure pulls the chromatids apart in anaphase?
surface area to volume
When a cell divides into two cells, what ratio increases?
prophase
When does DNA take on its compact chromosome form?
nucleus
Where are the chromosomes in a cell?
sea star
Which animal is known for its regenerative abilities?
Budding
Which form of eukaryotic asexual reproduction is used by both unicellular and multicellular organisms?
asexual
Which is faster, asexual or sexual reproduction?
Our cells have divided, causing us to grow larger.
Why are we bigger than we were last year?
The tough cell wall prevents the membrane from being pulled inward.
Why does a cell plate form in a plant cell instead of a fiber ring?
Sexual reproduction is much more complex; the DNA from both parents must be combined in special processes.
Why does sexual reproduction take longer than asexual reproduction?
Interphase
A cell grows, carries out normal functions, duplicates its organelles, replicates its DNA, and prepares for mitosis in which phase?
Asexual reproduction
A form a reproduction in which a parent produces offspring that are genetically identical
DNA
A molecule that contains information for an organism's growth and functions
Budding
A process in which an orgahnism develops tiny outgrowths
Yes
Are all prokaryotes (or the vast majority) unicellular?
No
Are buds always able to be produced from all parts of an organism?
No
Can eukaryotes reproduce by binary fission?
Yes
Can organisms have more than one bud at one time?
b
Cells wear out at ________ rates: a) the same b) different
nucleus
In mitosis, what part of the cell divides?
cell plate cell walls
In plant cell cytokinesis, a _______ grows between the nuclei and becomes part of the new cells' _______
reproduction
In unicellular organisms the function of cell division is what?
specialized
Instead of being completely identical, the cells in your body are _______
Prophase Nuclear membrane breaks down and DNA condenses to chromosome form
Name the first step of mitosis and describe it
Telophase New nuclear membranes form around each of the chromosome groups
Name the fourth step of mitosis and describe it
Metaphase Chromosomes line up in the center of the cell
Name the second step of mitosis and describe it
Anaphase Chromatids separate and move to opposite sides of the cell
Name the third step of mitosis and describe it
cell division, budding, regeneration
Name the three ways in which eukaryotes reproduce
binary fission
Name the way(s) in which prokaryotes reproduce
cell cycle
Normal sequence of development and division of a cell
Mitosis
Part of the cell cycle in which the nucleus divides
Regeneration
Process in which missing body parts are replaced by the growth of new tissue
att159 (anna thomas)
ditched me & made me go from being mad 2 being sad!!!
