Bio Review Agenda 2-1 Lit Obj: Reasoning Cont Obj: Review Cell Energy & Cell division Agenda: 1. Activator. 2. Review yesterday’s practice questions. 3. Finish Cells Review Packet Activator: choose two practice questions from yesterday you’d like to review. Homework: Complete “Big Picture Review Questions” for Tomorrow.

Big Picture Review: Cells part 2 ATPMeiosis

ATP ATP is stored energy Energy is released when the bond between the 2nd and 3rd phosphate group is broken, forming ADP. Adding another phosphate will change it back to ATP. ATP is like a charged battery. ADP is like an empty battery.

2.6 Vocabulary Reproduction- process by which living things make offspring. Asexual Reproduction – type of reproduction where offspring come from one individual, instead of two. Interphase- G1, S, and G2 stages of the Cell cycle; most of a cell’s life cycle is in this phase. Chromatin- Genetic Material of a bell before mitosis Centromere- where spindle fibers attach to pull chromosomes during Mitosis

Interphase Stage 1 - G1 (1st Growth) Cells increase in size (GROW) Normal daily activities Cell respiration Waste disposal Nutrient intake Protein synthesis

Interphase Stage 2 - S Phase (Synthesis) DNA duplication (DUPLICATE) Conditions get crowded…need more room!

Interphase Stage 3 - G2 (2nd Growth) Cell continues to grow (GROW 2) Prepares for Mitosis

Stage 4 - MITOSIS Time to divide Nuclei DIVISION Cells undergo mitosis in order to grow or to repair damaged cells.

Stage 5 - Cytokinesis Cell divides its Cytoplasm Two (2) cells formed!

Stages of Mitosis Prophase Metaphase Anaphase Telophase

PROPHASE DNA coils tightly & becomes visible as chromosomes. Nuclear membrane disappears Centrioles migrate to poles Centrioles: organelles that produce spindle Spindle fibers begins to form

METAPHASE Spindle fibers from centrioles attach to each chromosome. Chromosomes line up in the middle of the cell.

ANAPHASE Chromosomes are already separated into sister chromatids at the centromere. Spindle fibers shorten and each chromatid is pulled to the opposite end of cell.

TELOPHASE Separation of chromosomes into chromatids is completed Nuclear membrane reforms. Now have two nuclei in one cell Chromosomes uncoil

CYTOKINESIS Cytoplasm division Occurs after chromosomes separate and two nuclear envelopes reappear. Forms two, identical daughter cells (they are identical to the original cell)

Chromosomes come in matching sets -these are called homologous pairs

Cells in your body have a complete set (all 46) - they are called DIPLOID   Sex cells (sperm and eggs) only have half (23)  - they are called HAPLOID

When GAMETES combine, the ZYGOTE (offspring) gets half from mom (23) and half from dad (23) ZYGOTES are diploid  (46)

The process of creating a gamete (sex cell) is called MEIOSIS It is similar to mitosis, but  will produce 4 daughter cells that are each haploid.

MEIOSIS

Crossing-over increases the number of possible gene combinations