4.1 and 4.2 Notes
A. Autotrophs vs. Heterotrophs
•Autotrophs: make their own food (i.e. plants)
Go through both photosynthesis AND cell respiration
•Heterotrophs: do not make their own food (like animals) and get food from breaking down food
molecules. ONLY RESPIRATION!
B. ENERGY FLOWS!
•ATP: an energy carrying molecule
•Energy flows from the sun through all organisms
•Energy is required for growth and reproduction, movement and transportation of materials across cell
membranes.
C. Photosynthesis formula
D. Factors that affect photosynthesis
•Includes temperature, light intensity, amount of water, oxygen and CO2
E. Cell Respiration formula
4.3 Notes
A. Stages of Cell Division
Stage 1: Interphase
Stage 2: Mitosis
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Stage 3: Cytokinesis
B. Stage 1: Interphase
During interphase the cell grows, makes a copy of its DNA, and prepares to divide into two cells.
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During interphase the cell also copies all organelles needed for the new cell
Chapter 4 Text of Notes (1) ●
Replication is the process of making a copy of the DNA
C. Stage 2: Mitosis
During mitosis one copy of the DNA is distributed into each cell.
Mitosis has four distinct phases
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
D. Mitosis Phase 1: Prophase
During Phase 1: Prophase chromatin in the nucleus condenses to form chromosomes. Pairs of centrioles
move to opposite sides of the nucleus.
E. Mitosis Phase 2: Metaphase
During Phase 2: Metaphase the chromosomes line up across the center of the cell. At this time each
chromosome attaches to a spindle fiber at its centromere.
F. Mitosis Phase 3: Anaphase
During Phase 3: Anaphase the centromeres split, each chromosome separates. At this point the cell
stretches out as far as possible.
G. Mitosis Phase 4: Telophase
During Phase 4 Telophase the chromosomes become encased in their new nuclear envelope.
H. Stage 3: Cytokinesis
During Cytokinesis the cell membrane pinches in around the center of the cell, creating two distinct cells.
Chapter 4 Text of Notes (2)