Biology Concepts: Cell Cycle, Animal Systems, and Plant Structure
The Cell Cycle
Purpose: Growth, repair, and reproduction of cells.
Stages:
Interphase – Cell grows, DNA replicates, organelles duplicate
- G1: Growth
- S: DNA synthesis
- G2: Prep for division
Mitosis (M phase) – Division of the nucleus
Cytokinesis – Division of cytoplasm; two daughter cells form
Mitosis
Purpose: To produce identical daughter cells for growth and repair.
Phases:
Prophase – Chromosomes condense, spindle fibers form, nuclear membrane breaks down
Metaphase – Chromosomes line up at the cell
Pharmacognosy and Phytochemistry of Crude Drugs
Cardiotonic Drugs and Cardiac Glycosides
Definition: Cardiotonic drugs are substances that increase the force of myocardial contraction and improve heart function. They are primarily used to treat cardiac insufficiency and heart failure, and they typically contain cardiac glycosides.
Examples and Biological Sources
- Digitalis: Obtained from the dried leaves of Digitalis purpurea. Use: Enhances cardiac contraction.
- Strophanthus: Obtained from the seeds of Strophanthus kombe. Use: Strengthens heart pumping
Wound Definition and Tissue Repair Stages
What is a Wound?
A wound is a disruption or break in the normal continuity of the skin or other body tissues. It can result from injuries such as cuts, abrasions, punctures, surgical incisions, burns, or other trauma. Wounds may be open (where the skin is broken) or closed (such as bruises where the skin remains intact).
Phases of Wound Healing
Wound healing is a complex, orderly process that the body undergoes to repair tissue damage. It generally occurs in four overlapping phases:
Hemostasis Phase
Biology Fundamentals: Cell Structure to Genetics
Module 1: Cells as the Basis of Life
Key Concepts
- Cell Theory: All organisms are made of cells; cells are the basic units of life; all cells arise from pre-existing cells.
- Prokaryotes vs. Eukaryotes:
- Prokaryotes: No nucleus or membrane-bound organelles.
- Eukaryotes: Complex, possess membrane-bound organelles.
Organelles & Functions
| Organelle | Function |
| Nucleus | Stores DNA, controls activities. |
| Mitochondria | Site of aerobic respiration (ATP production). |
| Ribosomes | Protein synthesis. |
| Chloroplasts | Photosynthesis. |
| Golgi |
Understanding Photosynthesis and Cellular Respiration
Photosynthesis and Energy Storage
- Photosynthesis: A process that uses light energy to make glucose.
- Overall Purpose: To store energy in glucose.
- Equation: Carbon dioxide + Water + Light → Glucose + Oxygen
Chloroplasts and Pigments
- Chloroplast: The organelle where photosynthesis occurs.
- Chlorophyll: A pigment that absorbs light energy.
Light-Dependent Reactions
- Inputs: Light, water, ADP, and NADP+.
- Outputs: ATP, NADPH, and oxygen.
- Role of Water: It is split to release oxygen.
The Calvin Cycle (Light-Independent)
Read MoreTurtle Biology, Evolutionary History, and Natural Selection
The Biology and Classification of Turtles (Testudines)
Turtles (Testudines) are an order of reptiles (Sauropsida) characterized by having a wide, short trunk, and a shell that protects the internal organs of the body. The head, front legs, and tail protrude from the shell.
Key Anatomical Features
The most important feature of the turtle skeleton is that a large part of the spine is fused to the back of the shell. This skeletal structure makes breathing via rib cage movement impossible. Respiration
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