Term
true or false:
multicellular organisms begin life as multicellular cells. |
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Definition
false-
multicellular organisms begin life as a single cell. |
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Term
true or false:
the # of cells increase by cellular respiration. |
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Definition
false-
the # of cells increase by cellular reproduction. |
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Term
true or false:
reproduction occurs to replace worn-out or damaged tissues. |
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Definition
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Term
true or false:
asexual reproduction requires a sperm and an egg. |
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Definition
false-
asexual reproduction DOES NOT require a sperm and an egg. |
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Term
| what are two important cell processes? |
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Definition
1. growth
2. cell division |
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Term
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Definition
| when the cell duplicates its contents (including DNA and organelles) |
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Term
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Definition
| when the parent cell contents divide into two daughter cells |
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Term
chromosomes or chromatin?
DNA is packaged into... |
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Definition
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Term
chromosomes or chromatin?
DNA and associated proteins have the appearance of thin threads |
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Definition
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Term
chromosomes or chromatin?
a full set of ______ is passed onto each daughter cell |
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Definition
|
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Term
chromosomes or chromatin?
a thickened complex of DNA and proteins is... |
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Definition
|
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Term
chromosomes or chromatin?
_________ allow for easier distribution to daughter cells |
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Definition
|
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Term
| what are duplicated chromosomes composed of? |
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Definition
| sister chromatids joined at the centromere |
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Term
true or false:
sister chromatids have different DNA. |
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Definition
| false- sister chromatids have identical DNA. |
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Term
true or false:
just before cell division, chromosomes condense into chromatin. |
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Definition
false-
just before cell division, chromatin condense into chromosomes. |
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Term
| how many chromosomes do humans have? |
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Definition
|
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Term
| how are nucleosomes formed? |
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Definition
| when DNA is wrapped around histones |
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Term
| what is the orderly sequence of stages that takes place between the time a new cell has arisen to the point where it gives rise to 2 daughter cells called? |
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Definition
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Term
| how many stages does interphase include? |
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Definition
|
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Term
| what are the 3 stages of interphase called? |
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Definition
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Term
G1, S, or G2?
part of interphase |
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Definition
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Term
G1, S, or G2?
stage following DNA synthesis |
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Definition
|
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Term
G1, S, or G2?
stage before DNA replication |
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Definition
|
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Term
G1, S, or G2?
DNA synthesis |
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Definition
|
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Term
G1, S, or G2?
cell doubles organelles |
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Definition
|
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Term
G1, S, or G2?
results in each chromosome being composed of 2 sister chromatids |
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Definition
|
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Term
G1, S, or G2?
accumulates materials for DNA synthesis |
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Definition
|
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Term
G1, S, or G2?
extends to onset of mitosis |
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Definition
|
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Term
G1, S, or G2?
synthesizes proteins needed for cell division |
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Definition
|
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Term
G1, S, or G2?
makes decision whether or not to divide in this stage |
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Definition
|
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Term
| what is it called during interphase when the cell decides NOT to divide? |
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Definition
| G0, which means that replication has been arrested (stopped) |
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Term
true or false:
the majority of the cell cycle is spent in telophase. |
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Definition
false-
the majority of the cell cycle is spent in interphase. |
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Term
true or false:
interphase is the time when a cell performs its usual functions. |
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Definition
|
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Term
true or false:
the amount of time spent in interphase is the same for every cell. |
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Definition
| false- the amount of time varies widely depending on the cell. |
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Term
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Definition
| the M phase is the mitotic phase |
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Term
| what happens during the M phase? |
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Definition
| cell division occurs; division of the nucleus; and division of the cytoplasm |
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Term
| what is the division of the nucleus called? |
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Definition
|
|
Term
| what is the division of the cytoplasm called? |
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Definition
|
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Term
| what does mitosis create? |
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Definition
| 2 daughter nuclei that are genetically identical to each other and the parent nucleus |
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Term
true or false:
every animal has an even # of chromosomes. |
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Definition
|
|
Term
|
Definition
| part of the cytoskeleton made of microtubules that pull chromatids apart |
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|
Term
| how many phases is mitosis typically divided into and what are they called? |
|
Definition
4 phases:
prophase, metaphase, anaphase, and telophase |
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Term
| although mitosis is divided into phases, it is also known as a ____________ process. |
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Definition
|
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Term
true or false:
plants have 2 centrioles and an aster (array of microtubules). |
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Definition
false-
plants have centrosomes but lack centrioles. |
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Term
| what happens during prophase? |
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Definition
1. chromosomes condensed
2. chromatids held at centromere
3. spindle fibers begin to assemble
4. breakdown of nuclear envelope
5. spindle fibers from each pole attach to chromosomes
6. spindle fibers pull chromosomes to poles |
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Term
| what happens during metaphase? |
|
Definition
1. chromosomes are aligned at the
spindle equator |
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Term
| what happens during anaphase? |
|
Definition
1. sister chromatids separate and become daughter chromosomes
2. spindle fibers attached to the chromosomes disassembles
3. each pole receives a set of daughter chromosomes
|
|
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Term
| what happens during telophase? |
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Definition
1. spindle disappears
2. nuclear envelope begins to reform around daughter chromosomes
3. each nucleus contains the same # and type of chromosomes
4. division of cytoplasm begins (cytokinesis)
5. cleavage furrow appears |
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Term
true or false:
cytokinesis occurs in all plant and animal cells. |
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Definition
| false- cytokinesis accompanies mitosis in most but not all plant and animal cells. |
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Term
| mitosis with cytokinesis can result in multinucleated cells. what are 2 examples of multinucleated cells? |
|
Definition
1. muscle cells in vertebrate animals
2. embryo sac in flowering plants |
|
|
Term
| how is a cleavage furrow produced? |
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Definition
| a contractile ring made of actin filaments forms a constriction around the center of dividing cell, like pulling on a drawstring |
|
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Term
| when does a cleavage furrow appear? |
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Definition
| just as anaphase ends and telophase begins |
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Term
| why is there no cleavage furrow seen in plant cells? |
|
Definition
| the plant's rigid cell wall prevents furrowing |
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Term
| why must the cell cycle be controlled? |
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Definition
| control ensures that the stages occur in order and that the cycle continues only when the previous stage is successfully completed |
|
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Term
| what are 3 major checkpoints in the cell cycle? |
|
Definition
1. G1
2. G2
3. mitotic stage |
|
|
Term
| what happens at the G1 checkpoint in the cell cycle? |
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Definition
| cell commits to divide; proper growth signals must be present to proceed; DNA integrity checked and repaired if necessary |
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Term
| what is it called during the DNA integrity check of G1 when DNA cannot be repaired and must be destroyed? |
|
Definition
apoptosis, which is programmed
cell death |
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Term
| what happens during the G2 checkpoint of the cell cycle? |
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Definition
| verifies that DNA has been replicated and damaged DNA is repaired |
|
|
Term
| what happens during the mitotic stage checkpoint of the cell cycle? |
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Definition
| verifies that metaphase has ended and anaphase can begin; all chromosomes must be attached to the spindle to pass |
|
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Term
| a molecule that stimulates or inhibits an event is called a... |
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Definition
|
|
Term
| what are two types of signals for cell division? |
|
Definition
| external and internal signals |
|
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Term
|
Definition
| remove a phosphate from ATP and add it to other molecules |
|
|
Term
| when are cyclins present? |
|
Definition
| only during stages of the cell cycle |
|
|
Term
| why is the destruction of cyclins necessary? |
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Definition
| destruction of cyclins at the appropriate time is necessary for normal cell cycle progression |
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|
Term
| S-cyclin must combine with what type of kinase in order for the S phase to occur? |
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Definition
|
|
Term
| M-cyclin must combine with what type of kinase for mitosis to occur? |
|
Definition
|
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Term
| what are two examples of external signals and what do they do? |
|
Definition
1. epidermal growth factor- stimulates the skin near an injury to finish cell cycle and repair the skin
2. estrogen- stimulates the lining of the uterus to divide and prepare for egg implantation |
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Term
|
Definition
| cells stop dividing when they touch one another |
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Term
| once apoptosis occurs, what happens to the remaining cell fragments? |
|
Definition
| they are engulfed by WBCs |
|
|
Term
| how and why does apoptosis occur? |
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Definition
| apoptosis is started by internal or external signals and helps to keep the # of cells at an appropriate level and rid cell of mutations/damaged DNA |
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|
Term
| what are 2 examples of how apoptosis helps? |
|
Definition
1. ridding the frog of its tail from the tadpole stage
2. placing webbing between human fingers and toes |
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Term
|
Definition
| a disease of the cell cycle in which cellular reproduction occurs repeatedly without end |
|
|
Term
| how is cancer classified? |
|
Definition
|
|
Term
cancer classification:
carcinoma, sarcoma, or leukemia?
cancer of the blood |
|
Definition
|
|
Term
cancer classification:
carcinoma, sarcoma, or leukemia?
cancer of epithelial tissue lining organs |
|
Definition
|
|
Term
cancer classification:
carcinoma, sarcoma, or leukemia?
cancer arising in muscle or connective tissue |
|
Definition
|
|
Term
| what is the development of cancer called? |
|
Definition
|
|
Term
| what is it called when a tumor travels to a new place in the body? |
|
Definition
|
|
Term
| what is it called when a tumor grows its own blood vessels for nourishment? |
|
Definition
|
|
Term
true or false:
cancer cells differentiate. |
|
Definition
| false- cancer cells do not differentiate because they do not contribute to any body function |
|
|
Term
true or false:
tumors do not respond to inhibitory signals and may divide repeatedly. |
|
Definition
|
|
Term
benign or malignant?:
invasive and may spread |
|
Definition
|
|
Term
benign or malignant?:
contained within a capsule |
|
Definition
|
|
Term
true or false:
cancer cells have an abnormal nuclei. |
|
Definition
|
|
Term
true or false:
cancer cells have a normal # of chromosomes. |
|
Definition
| false- cancer cells have an abnormal # of chromosomes |
|
|
Term
true or false:
cancer cells undergo apoptosis. |
|
Definition
| false- cancer cells do not undergo apoptosis, which is why cells with damaged DNA are permitted to divide |
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|
Term
|
Definition
| either remove tumor or interfere with the ability of the cancerous cells to reproduce |
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|
Term
| how does radiation therapy and chemotherapy affect cancer cells? |
|
Definition
| they damage DNA or some aspect of mitosis |
|
|
Term
| what is a drawback to radiation therapy and chemotherapy? |
|
Definition
| they lead to side effects |
|
|
Term
how does hormone therapy used to
treat cancer? |
|
Definition
| designed to prevent cells from receiving signals for continued growth and division |
|
|
Term
| name 4 ways that you can prevent cancer? |
|
Definition
1. avoid smoking- 30% of all cancer deaths
2. avoid sun exposure- melanomas
3. avoid heavy alcohol use
4. eat healthy foods |
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