GEN BIOT PDF - Biology Past Paper

Pointers: 1.Cell Cycle stages 2. Mitosis and Meiosis (Crossing over) 3. Aneuploidy (Yung mga disorders Yung mga definition ) 3. Diffusion 4.Osmosis 5. Label the Parts of Chromosomes ...

Pointers: 1.Cell Cycle stages 2. Mitosis and Meiosis (Crossing over) 3. Aneuploidy (Yung mga disorders Yung mga definition ) 3. Diffusion 4.Osmosis 5. Label the Parts of Chromosomes  ANEUPLOIDY The presence of abnormal number of chromosomes in a cell. DEFINITION OF TERMS: ✔ Aneuploid is the person with aneuploidy. ✔ A karyotype is the technique used to determine aneuploidy. ✔ A karyogram is the visual profile of chromosomes arranged inappropriate order. What's the CAUSE of Aneuploidy? NONDISJUNCTION The failure of homologous chromosomes OR sister chromatids to separate properly during cell division. ✔ The risk of having an aneuploid offspring increases as a woman ages. ✔ May occur during anaphase I OR during anaphase II. TRISOMY The presence of an extra chromosome in some or all body's cells. ✔ Monosomy is having a single copy instead of the normal pair COMMON ANEUPLOID DISORDERS MONOSOMY TRISOMY TURNER SYNDROME (MONOSOMY X) PATAU SYNDROME (TRISOMY 13) EDWARD SYNDROME (TRISOMY 18) DOWN SYNDROME (TRISOMY 21) TRIPLE SYNDROME (TRISOMY XXX or METAFEMALE) KLINEFELTER SYNDROME (TRISOMY XXY)  PASSIVE TRANSPORT The movement of substances across the cell membrane WITHOUT the aid of biochemical energy (ATP). 1. Diffusion 2. Facilitated Diffusion 3. Osmosis 1. DIFFUSION The movement of molecules of solutes from one area of HIGH concentration to an area of LOW concentration. Five factors influence diffusion: 1. Concentration 2. Temperature 3. Charge 4. Molecule Size 5. Pressure 2. FACILITATED DIFFUSION “FACILITATED TRANSPORT” Uses integral proteins (“transport proteins”) to move other ions and small molecules across the cell membrane. A concentration gradient (difference in the concentrations of substances or molecules between two areas) exists that would allow these materials to diffuse into the cell without expending cellular energy.  3. OSMOSIS The movement of water across a semi- permeable membrane from an area of LOW solute concentration to HIGH solute concentration. Three (3) Types of Solution Under Osmosis: a. Isotonic Solution b. Hypotonic Solution c. Hypertonic Solution a. Isotonic Solution - Normal - Concentration inside the cell is EQUAL to that of the solution. - Cell is at EQUILIBRIUM. b. Hypotonic Solution - Diluted - Swollen - Greater concentration of solute inside the cell than outside. - Water enters the cell. c. Hypertonic Solution - Concentrated - Shrunken - Greater concentration of solute outside the cell than inside. - Water leaves the cell.