Cellular Organelles and Animal Tissues Explained
Endoplasmic Reticulum
A system of membranes in the cytoplasm that forms a complex network of tubules and sacs connected with the nuclear membrane. It may be free or associated with ribosomes. Functions include transport and storage of chemicals, synthesis of lipids (in the smooth endoplasmic reticulum) and proteins (in the rough endoplasmic reticulum), and destruction of toxic substances.
Ribosomes
Very small organelles consisting of RNA and proteins. Their function is protein synthesis.
Golgi Apparatus
A
Read MoreGregor Mendel: The Father of Genetics
Why did Mendel join the monastery?
He joined for financial stability and educational access. The monastery provided him the time, space, and resources to study and conduct scientific research.
What was Mendel’s former education?
He studied at the University of Vienna, where he learned mathematics, physics, and biology, shaping his analytical approach to science.
What hobbies did Mendel have?
Mendel enjoyed gardening, beekeeping, and conducting plant experiments, especially studying how traits passed
Read MoreCore Concepts in Biology: Evolution, Classification, and Life Forms
Evolutionary Biology Fundamentals
- The original source of all genetic variation is: Mutation
- Microevolution occurs when: Changes in allele frequencies in a population occur over generations.
- What is the only evolutionary mechanism that consistently leads to adaptive evolution? Natural selection.
- The evolutionary effects of genetic drift are greatest when: The population size is small.
- Which of the following descriptions illustrates phenotypic variation caused by the environment? Diet of caterpillars changes
Genetic Engineering and Stem Cells: Advances in Biotechnology
The Genetic Engineering Process
Genetic engineering involves a precise process:
- The DNA containing the desired gene is cut with specific restriction enzymes.
- Vector DNA is cut with the same restriction enzymes to ensure complementary ends.
- The DNA fragment with the desired gene is ligated (bound) to the vector.
- The resulting molecule is recombinant DNA (DNA from different sources). This recombinant DNA is then introduced into a host cell.
- The host cell, typically a bacterium, divides many times, creating
Essential Medical Concepts: Diseases, Treatments, and Body Systems
Common Health Conditions
Malformations and Birth Defects
Malformations are conditions present at birth, resulting from disorders during embryonic development or childbirth.
Autoimmune Diseases
Autoimmune diseases are conditions where the immune system mistakenly attacks the body’s own tissues, producing molecules (antibodies) that cause damage to various organ systems. Examples include systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. Immunomodulator drugs can help control
Read MoreBiological Classifications: Kingdoms, Organisms, and Bacteria
Kingdom Plantae: Characteristics
Composed of multicellular, eukaryotic, autotrophic, photosynthetic organisms. They exhibit a vast variety in form and dimensions, ranging from small plants like mosses to giant trees, all capable of photosynthesis.
Kingdom Animalia: Metazoa
Includes all animals. These are multicellular eukaryotic organisms whose cells associate to form tissues. They are heterotrophic, feeding on organic compounds, and primarily reproduce sexually (via egg and sperm).
Key Metazoan Phyla
- Sponges