Understanding Chromosomes, Cell Reproduction, and Mitosis
Chromosome Structure
Chromosome: These are stick-shaped structures representing chromatin condensation during mitosis. Their size varies according to species.
Centromere: This is the primary constriction point, marking the start of the distal arms. Telomeres may have secondary constrictions near them.
Kinetochore: This protein structure appears at the centromeres and acts as a microtubule organizing center, where the spindle fibers attach.
Telomeres: These are protective caps at chromosome ends, preventing
Read MoreRespiratory System: Anatomy, Function, and Gas Exchange
The Respiratory System: From Air to ATP
O2 intake transforms to ATP.
The Pathway of Air
Driving: Nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.
Nose
Nares (nostrils): Yellow (smell), reddish (warms air).
Coana: Opening of communication between nostrils and rhino…
Respiratory System: Entrance inland O2 resp. to lungs.
Nasal mass begins, pharynx, larynx, trachea, bronchi,
Bronchioles and allows CO2 output through lungs,
Producing alveoli gas exchange. Via High: mouth, pharynx, larynx = syst.
Read MoreMicrobial Diversity and Roles in Ecosystems
F.1.8 Virus Structure and Diversity
A virus is a non-cellular agent consisting of a protein coat (capsid) and genetic material.
- The genetic material may be DNA (adenovirus) or RNA (retrovirus) and may be single-stranded or double-stranded.
- For some viruses, the protein coat may be exposed (naked capsid), while others may be covered in a membranous bilayer (enveloped capsid).
- Retroviruses have a reverse transcriptase component to allow for the production of viral DNA.
F.1.9 Microscopic Eukaryote Diversity
Examples
Read MoreUnveiling Paleontology: Fossils, Evolution, and Hominization
Paleontology: Unveiling the Past
Paleontology studies the remains of living beings that lived in the past. Since antiquity, fossil remains of animals have been discovered. To explain their existence, the diluvian theory was used, according to which such remains were those of animals now extinct as a result of “Noah’s Flood.” This scenario could not explain the progressive ratio found from fossils dating in older times to more recent times. Thus, the diluvian theory was replaced by the theory of catastrophes.
Read MoreGenetic Engineering: Techniques, Vectors, and PCR Explained
Genetic Engineering: An Overview
Genetic Engineering is a technique that consists of introducing genes into the genome of an individual who lacks them. It is performed by restriction enzymes that are able to “cut” DNA at specific points. Recombinant DNA is formed by inserting a DNA segment into a foreign DNA receiver. For example, the introduction of viral DNA into a cell’s DNA.
DNA Recombination Techniques
This includes a set of biotechnology techniques. DNA recombination allows us to obtain unlimited
Read MoreMendelian Genetics: Laws, Inheritance, and Applications
Gregor Mendel and the Foundations of Genetics
Gregor Mendel (1822-1884)‘s experiments on plant breeding were central to the development of genetics. He meticulously planned his experiments by choosing plants with contrasting characters.
Materials Used in Mendel’s Experiments
Materials used: Green and yellow seeds, seeds with smooth and rough surfaces. These materials provided the contrasting characters necessary for his research.
Mendel recognized that inheritance follows specific laws and that the
Read More