LESSON 4 Flashcards
Living things grow by producing _____, NOT because each cell increases in size
more cells,
____ of damaged tissue
Repair
If cell gets too ___, it cannot get enough ____ into the cell and wastes out of the cell
big ; nutrients
Many organisms, especially ____ organisms, reproduce by means of cell division – called asexual reproduction
unicellular
Many organisms, especially unicellular organisms, reproduce by means of cell division – called ____ reproduction
asexual
DNA is located in the ____ and controls all cell activities including cell division
nucleus
Long and thread-like DNA in a non-dividing cell is called _____
chromatin
Doubled, coiled, short DNA in a dividing cell is called _____
chromosome
2 identical “sister” chromatids attached at an area in the middle called a _____
centromere
Why does DNA need to change from chromatin to chromosome?
More efficient division
Every organism has its own specific number of ____
chromosomes
Human = ___ chromosomes or ___ pairs
46 ; 23
Dog = __ chromosomes or pairs
78; 39
Goldfish = __ chromosomes or pairs
94 - 47
Lettuce = ___ chromosomes or ___ pairs
18; 9
All ______) cells in an organism have the same kind and number of chromosomes
somatic (body
______ – series of events cells go through as they grow and divide
Cell Cycle
Cell grows, prepares for division, then divides to form 2 daughter cells
cell cycle
Interphase
G1 Phase
S(synthesis) Phase
G2 Phase
M(Mitotic) Phase
Prophase
Metaphase
Anaphase
Telophase
period of cell growth and development
interphase
Where the cell spends most of its time the whole cell cycle
interphase
During ___ the cell also grows, carries out normal cell activities, replicates all other organelles
Interphase
first gap
G1 phase
Cell increase in size and volume
G1 phase
Carbohydrates, lipids, proteins, and enzymes are produced in preparation for S and M phase
G1 PHASE
DNA replication stage
s phase
Synthesis of DNA
s phase
DNA that will be passed on the daughter cells in M phase is replicated
s phase
Second gap
G2 Phase
Replenishment of energy and synthesis of Tubuline Dimers are produced
G2 Phase
Replenishment of energy and synthesis of Tubuline Dimers are produced
G2 Phase
Preparation for cell division
G2 Phase
division of the nucleus into 2 nuclei, each with the same number of chromosomes
mitosis
____ occurs in all the somatic (body) cells
Mitosis
Why does mitosis occur?
So each new daughter cell has nucleus with a complete set of chromosomes
Chromosomes coil up
prophase
Nuclear envelope disappears
prophase
Spindle fibers form
prophase
Chromosomes line up in middle of cell
metaphase
Spindle fibers connect to chromosomes
metaphase
Chromosome copies divide
anaphase
Spindle fibers pull chromosomes to opposite poles
anaphase
Chromosomes uncoil
telophase
Nuclear envelopes form
telophase
2 new nuclei are formed
telophase
Spindle fibers disappear
telophase
_____ — the division of the rest of the cell (cytoplasm and organelles) after the nucleus divides
Cytokinesis
In animal cells the cytoplasm pinches in, _____ form.
cleavage furrow
In plant cells a _____ forms
cell plate
After mitosis and cytokinesis, the cell returns to ______ to continue to grow and perform regular cell activities
Interphase
•____ controls all cell activities including cell division
DNA
•Some cells lose their ability to control their rate of cell division – the DNA of these cells has become damaged or changed
mutation
•These super-dividing cells form masses called ____
tumors
____ tumors are not cancerous – these cells do not spread to other parts of the body
Benign
•_____ tumors are cancerous – these cells break loose and can invade and destroy healthy tissue in other parts of the body (called metastasis)
Malignant
these cells break loose and can invade and destroy healthy tissue in other parts of the body
matastasis
