1What is the purpose of cell division?
It is essential for growth, development and repair
2How do chromosomes relate to chromatin?
just before cell division occurs chromatin condenses multiple times into large loops which creates chromosomes
3How many chromosomes do humans have?
46, 23 pairs
4Why are there two of each chromosome?
it makes it easier for the cell to move DNA from the old cell to the new one; it helps increase the variety and stability of a species
5Each chromosome duplicated consists of what?
they are composed of two identical halfs called sister chromatids, held together at a centromere
6Each chromatid consists of what?
they each consist of an identical DNA double helix
7interphase
most of the cell cycle is spent in interphase. the cell grows and DNA replicates and is checked for errors. there are three stages: G1 (organelles are reproduced), S (DNA is replicated), G2 (proteins involved with cell division are made)
8G1
organelles are reproduced
10G2
proteins involved with cell division are made
11What are the cell cycle phases?
interphase, mitosis, cytokinesis
12mitosis
orderly separation of duplicated chromosomes, ensuring that each daughter cell receives a complete and identical set. results in two daughter cells
13What are the phases of mitosis in animal cells?
prophase, metaphase, anaphase, telophase
14cytokinesis
division of cytoplasm, nucleus is formed around daughter chromosomes
15prophase
chromosomes condense fully, nuclear envelope degrades, spindle fibers attach
16metaphase
chromosomes line up at the equator
17anaphase
separation of chromosomes (sister chromatids) begins to occur and move to opposite poles of cell
18telophase
cell begins to to clevage (separate into two cells), spindles degrade, and the nuclear envelope begins to form around daughter chromosomes (in their single form)
19If the cell is no longer going through cell division, what stage is this called?
G0, the resting phase where the cell has left the cycle and has stopped dividing
20What types of cells are set in the G0 phase?
neurons and muscle cells
21spindle
has spindle fibers composed of cytoskeletal elements like microtubles, controls the separation of chromosomes. they attach at the centromere and assist to pull apart the the chromosome so each half ends up in a daughter cell
22How many cells are made after one round of mitosis?
2
23Why are mitosis cells identical?
the duplicated DNA of the parent cells are equally distributed to the daugher cells, creating identical cells
24How is the cell cycle regulated?
it is regulated by cell cycle checkpoints
25apoptosis
programmed cell death
26How is apoptosis important to adult humans?
it prevents abnormal cells that could become cancerous from appearing. which could cause tumors
27How is apoptosis important to developing embryo?
contributes to the appropriate formation of various organs and structures
28What is cancer?
a disease from uncontrolled cell division
29What are the main characteristics of cancer?
lack differentation, may be immortal (divide repeatedly), no contact inhibiton, have abnormal nuclei with abnormal number of chromosomes, dont undergo apoptosis, form tumors, undergo metastasis and angiogenesis
30carcinogenesis
development of cancer
31metastasis
cells travel to start new tumors
32angiogenesis
form new blood vessels from pre-existing vessels to nourish themselves
33benign tumor
contained within a capsule, so it cant spread
34malignant tumor
invasive and may spread
35What are some cancer treatments?
surgery, radiation, chemotherapy, hormonal therapy, inhibitiory drug therapy, stem cell therapy, genetic therapy