BIOLOGY REVIEWER
Cell - the basic unit of life
- Discovered by Robert Hooke in 1665 through the microscope
Matthias Schleiden - discovered that plants are made of cells
Theodore Schwann - discovered that animals are made of cells
Cell Theory - all organisms are made of cells
2 types of cells:
PROKARYOTIC CELLS
EUKARYOTIC CELLS
Organelles - Enables the cell to live, grow, and reproduce
Prokaryotic Cells - has no membrane-covered organelles
Eukaryotic Cells - has a membrane-covered organelles
Mitochondria - power center or cell
Nucleus - Mayor's office, control center of cell
- contains DNA
Ribosomes - Where proteins are made
- factories of the cell
Amino Acids - building block
Endoplasmic Reticulum - transportation system of cell
ROUGH ER = ribosomes attached
SMOOTH ER = no ribosomes attached
Golgi complex - packaging house of cell
Lysosomes - police men
- digests food particles
- protects cell
Vacuole - stores water, food and wastes
- largest organelle in a plant cell
Cell wall - cellulose
- protects and supports the cell
- found only in plant cells
Chloroplasts - Where photosynthesis takes place
Chlorophyll - makes plants green
Robert Hooke - discovered microscope
Materials used by Robert Hooke :
• Glass • Crystal • Point of a pin • Body of a flea • Frozen urine
Anton Van Leeuwenhoek - credited as the father of modern microscope
Rudolf Virchow / Rudolf Carl Virchow - proposed that all cells come from other cell through
cell division
Cell Membrane - also known as plasma membrane
Cytoplasm - jelly-like fluid contained in the cell that holds the organelles
Oogenesis - stages of meiosis in the female ovarian maturation, hormones and cycles
ovulation
Spermatogenesis - stages of meiosis in the male differentiation (spermiogenesis)
Gamete could be egg or sperm
Gametogenesis: production of eggs or sperm
Oogenesis: production of eggs
Spermatogenesis: production of sperm
Spermiogenesis: differentiation of sperm morphology
Follicle: where eggs mature in the ovary
Ovulation: release of egg from follicle
Polar body: nonfunctional product of meiotic divisions in oogenesis
Zygote: Fertilized egg
Oogonia: mitotically dividing cells in the ovary, will become Oocytes
Primary oocyte: decision has been made to undergo meiosis, cell has grown. Cells are
arrested at this stage until puberty.
Secondary oocyte: has completed first meiotic division the division was unequal in terms of
cytoplasm
Ovum: Ovulated egg, ready to be fertilized. If fertilized, the second meiotic division will occur,
another polar body
Tunica albuginea is thickened on the posterior surface of the testis to form the mediastinum
testis
Leydig Cells - web of loose connective tissue that is rich in blood and lymphatic vessels,
nerves, and interstitial cells
M-Manufacturing
B-Breakdown
EP- Energy Processing
SMC- Structural Support, Movement, and Communication
CELL DIVISION AND CELL CYCLE
Mitosis is what helps us grow
Meiosis is why we are all unique
Sister chromatids
-One of two copies of chromosome connected at centromere after replication
•Centromere
-Attachment point of sister chromatids
Homologous pair of chromosomes
-Matched pair of chromosomes
- 23 pairs of chromosomes in humans
Spindle Fibers - Made up of microtubules
- Form at opposite ends or poles of cell
Centrosome - Structure from which the spindle apparatus develops
Haploid - only one set of chromosomes
Diploid - two sets of chromosomes
Gametes - Reproductive haploid cells, also called germ cells
- Human female gametes are called eggs
-Human male gametes are called sperm
CELL CYCLE
- INTERPHASE
- Mitosis:
Prophase, Metaphase, Anaphase, Telophase
- Cytokinesis
Interphase - cells normal process of living
- G1 (Gap 1) - cellular growth
- S (Synthesis) - DNA is replicated
- G2 (Gap 2) - Cell gets ready for cell division to take place
Mitosis
- cell division is the process of making new cells
- parent cell divides into two genetically identical diploid cells
Prophase
•Early prophase
–Chromosomes condense to become visible
•Late prophase
–Nuclear envelope breaks up
–Spindle fibers
•Form in the cytoplasm at opposite poles
Metaphase
•Spindle fully develops
Anaphase
•Paired chromosomes separate into daughter chromosomes
Telophase
•Two distinct nuclei form at poles
Cytokinesis
•Cytoplasm divides to produce two cells
Meiosis
•Cell division in sex cells
•Two part process leading to making of gametes
First: Meiosis I
–Separates homologous chromosomes
–Cells reduced from diploid to haploid
Second: Meiosis II
–Separates sister chromatids
Recombination - Rearrangement of genes to produce genetic variation in gametes
types: crossing over
independent assortment
Prophase 1 - Chromosomes begin to condense, become visible
Metaphase 1 - Paired homologous chromosomes line up on metaphase plate
Anaphase 1 - Homologous pairs separate and move toward opposite poles
Telophase 1 - Chromosomes arrive at the spindle poles
Prophase 2 - Chromosomes become visible again
Metaphase 2 - Individual chromosomes line up on the metaphase plate
Anaphase 2 - Sister chromatids separate and move toward the spindle poles
Telophase 2 - Chromosomes arrive at spindle pole
End result of Meiosis = Four genetically unique daughter cells
CELL MEMBRANE
Cell membrane is a semipermeable membrane.
Homeostasis is the ability or tendency to maintain internal stability in an organism.
Phospholipid bilayer consists of two layers of phospholipids
- Hydrophobic = water-hating
- Hydrophilic = water-loving
Characteristics of Molecules that Affect their Ability to Cross the Cell Membrane
1.Size
2.Charge
3.Solubility
Different Ways of Molecule Movement Across the Cell Membrane
1.Passive Transport
2.Active Transport
3.Bulk Transport
Concentration gradient is the difference between the amount of molecules present at two
regions, which determines the movement of molecules.
Diffusion is the movement of molecules from an area of high concentration of the molecules to
an area with a lower concentration.
Dynamic equilibrium is the continuous movement where there is no overall change in
concentration.
