Cells 1
How does the process of mitosis help to repair a wound?
A stem cell in an animal cells divides by mitosis. What is true about the 2 daughter cells?
The both have the same DNA sequence. (genetically identical)
How did the invention of the light microscope lead to the development and refinement of the cell theory over time?
As microscopes became more powerful, scientists could see additional structures within the cell.
What hypothesis about cells was found later to be wrong by scientists?
That cells are formed spontaneously by free cell formation.
What best explains why a group of cells performs better than one large cell?
As the cell gets larger, the distance from the nucleus to the membrane increases, thereby reducing its ability to function.
Which of these cells types would most likely have the highest rate of mitosis? (divide more frequently)
a. nerve cell c. cell in lens of eye
b. muscle cell d. cell in lining of intestine
d. Cells in the lining of the intestines
What factor is most important in the cell differentiation that occurs during the metamorphosis of a tadpole to a frog or a caterpillar into a butterfly?
The expression of different genes at different times.
After fertilization, a single cell divides successfully to form a multicellular structure. What happens next in order for the structure to develop tissues and organs to meet the needs of the organism?
They undergo differentiation into particular body parts.
Cell groups that are cancerous should have a _______________ percent of cells in interphase than noncancerous cells.
lower
What will be the end result of mitosis?
Two identical daughter cells
A scientist is comparing cancer cells to noncancerous cells. They should notice that the cancer cells have a ___________ rate of cell division and a __________
response to inhibiting factors.
Higher
Lower
During what phase of mitosis do chromosomes line up in the middle (equator) of the cell?
Metaphase
What are the phases of mitosis in order?
Prophase, metaphase, anaphase, telophase
(PMAT)
During differentiation, _________ cells divide and become different types of _______________ ___________ that carry out functions within the organism. These cells will differ from the parent cells by ____________ _____________ ___________.
1. stem
2. specialized cells
3. expressing different genes
During which phase of the cell cycle do cells remain in the longest? (Where they are growing, copying DNA and other organelles, and preparing for division/PMAT)
Interphase
A cell with 4 chromosomes underwent mitosis, but an error prevented the cell from undergoing cytokinesis. What would be the most likely result of this?
One cell with 2 nuclei and each nucleus would have 4 chromosomes.
Why would stem cells be modeled by people who research ways to treat medical conditions?
Growth and Development: A scientist is studying the processes of growth and development in multicellular organisms. She is also comparing these processes with similar processes in prokaryotes. **The scientist studies two cells from a multicellular organism. One cell is from the stomach of the organism, while the other cell is from the skin. Fill in the blanks with “the same” or “different”.
The cells’ nuclei would contain the _______ genetic information. The cells would express ________ genes. The cells would most likely have _______ structures and functions. The process by which the cells would divide would be ____ _________.
same
different
different
the same
The scientist compares the process of mitosis with the process of binary fission. Tell whether each statement is mitosis or binary fission or both.
Occurs in prokaryotic cells–a._____________
Involves circular chromosomes- b.____________
Involves cytokinesis into daughter cells- c. ______
Involves DNA, which is contained in a nucleus-d. ____
May involve differentiation into specialized cells-e.___
a. binary fission
b. binary fission
c. both
d. mitosis
e. mitosis
How does the surface area to volume ratio affect the health of a cell? (potato lab!!!)
As cells get larger, the surface area to volume ratio gets smaller. To remain healthy, cells need a high ratio of surface area to volume so cells can take in nutrients and get rid of wastes faster. (If the nucleus is too far away from the cell membrane, passage is affected.)
What are the 3 parts of the cell theory?
1. All cells come from other cells.
2. All living things are made of cells.
3. Cells are the basic unit of life.
How does the process of mitosis support the growth and repair of organisms?
1. Chromosome separation results in formation of new cells.
2. The division of parent cells into 2 daughter cells, increases the overall number of cells in an organism.
Cell division is influenced by internal and external events. Tell whether each event is external or internal.
1. Cyclins activate enzymes to move cell cycle along. 2. Contact with other cells causes it to stop dividing.
3. Kinases control phosphate addition regulating cell cycle. 4. Radiation causes mutations in cell.
1. internal
2. external
3. internal
4. external
a. Several factors regulate processes of interphase and cell cycle. Name one type of factor that controls cell division. b. Then name how damage to one of these factors can affect the cell division process.
a. genetic signals, hormones released by other cells,
physical contact with other cells,proteins in the cytoplasm
b. When damage occurs to the mechanisms that control cell division, cells can reproduce out of control causing tumors.
How does a stem cell differ from a neuron or an epithelial cell?
Neurons and epithelial cells can ONLY make other neurons and epithelial cells, but stem cells can make different kinds of cells. (This makes them important in the development of multicellular organisms because they can turn into many different types of cells which make tissues that perform different functions.)