I- DNA Using DNA to Make Proteins: As You grow cells divide producing new cells. These cells become specialized organs and grow larger.

Your body is made up of many different proteins. Proteins determine your eye color, hair color, bone structure, etc…….

Instructions for making proteins are stored in chromosomes which are made up of DNA molecules. DNA consist of two long strands forming a twisted ladder.

The double strands in a molecule are made up of sugars and phosphates. Nitrogen bases make up the rungs of the ladder.

Bases = ~Adenine (A) combines with Thymine (T) ~Guanine (G) combined with Cytosine (C) ~The sequence of three bases is a chemical code called a codon. Bases Handle = Sugars & Phosphates Codon

The DNA molecule is large, codes for humans are on 46 chromosomes in most cells or 23 pairs.

Proteins in cytoplasm use instruction from the nucleus for building Proteins in cytoplasm use instruction from the nucleus for building. The nucleus sends messengers called RNA (ribonucleic acid) a single strand of sugar, phosphates, and bases (DNA is a double strand)

B Making DNA Copies When cells reproduce DNA must be copied exactly B Making DNA Copies When cells reproduce DNA must be copied exactly. These copies give each new cell the same instructions as the original cell.

DNA Copies DNA molecules separate at the bases. The separated bases pair up with free bases. Now we have two DNA molecules that are identical.

Cell division that occurs in a series of stages, or phases. C- Mitosis Notes Cell division that occurs in a series of stages, or phases. 1st: INTERPHASE • Chromosomes are copied (# doubles) • Chromosomes appear as threadlike coils (chromatin) Resting Stage or Phase

2nd: PROPHASE • Mitosis begins (cell begins to divide) Spindle fibers Nuclear Membrane Starts to Disappear Centrioles • Mitosis begins (cell begins to divide) • Centrioles (or poles) appear and begin to move to opposite ends of cell. • Spindle fibers form.

3rd: METAPHASE • Chromatids (Double chromosomes) attach to the spindle fibers. Chromatids line up in the middle of cell.

4th: ANAPHASE • Chromatids (Double chromosomes) separate and begin to move to opposite ends of the cell

5th: TELOPHASE • Two new nuclei form. Nuclear membrane • Two new nuclei form. • Chromosomes appear as chromatin (threads-like) • Mitosis ends

6th: CYTOKINESIS • Cell membrane forms around two daughter cells - each with its own nucleus with identical chromosomes

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6th: CYTOKINESIS in Plant Cell cell plate • Cell membrane forms around two daughter cells - each with its own nucleus with identical chromosomes. A cell plate forms.

F- Sexual Reproduction in Plants. 1- The flower is the reproductive organ in a plant. 2- Parts of a Flower a-Stamen = male contains the anther which produces pollen grain (male gamete) and the filament holds up the anther.

3- Pistil = female contains the ~Stigma sticky to catch pollen, ~style tube leading to ovaries, ~ovaries which contain ovules the eggs (ovum female gamete) of the flower.

D- Sexual Reproduction: Involves the D- Sexual Reproduction: Involves the joining of two special reproductive cells, one from each parent. 1- These sex cells or gametes have half the number of chromosomes as the body cells. 2- Gametes are formed by a special type of cell division called meiosis.

3- During sexual reproduction the. sperm and egg cell join this is 3- During sexual reproduction the sperm and egg cell join this is called fertilization. a- When they join they form one cell with a complete set of chromosomes.

1-Forms new identical cell through the process of mitosis. E-Development of the Fertilized Egg: A Fertilized egg is called a zygote 1-Forms new identical cell through the process of mitosis. 2- This process (Differentiation) or cleavage continues forming more and more cells. 3- Sexual reproduction leads to variation in offspring.