Understanding Evolution: Evidence, Theories, and Mechanisms
Evolution is the process that explains the diversity of species. It is caused by changes transmitted to offspring. Evolution is a fact.
Evidence of Evolution
Palaeontology
Palaeontology is the study of fossils (remains of past organisms). Dating determines when a fossil or rock was formed or when a geological event occurred. Dating can be relative or absolute.
Methods of Dating
- Position of strata (depth = oldest)
- Radioactive isotopes
Biogeography
Each continent has its flora and fauna. The presence of some
Read MoreSputum and Vomit: Collection, Analysis, and Types
1. Sampling of Nasal Discharge
It involves introducing a sterile swab through the nose and gently rotating it until reaching the nasopharynx. The swab is then placed in a properly labeled transport tube and sent to the laboratory.
2. Sampling of Throat
Contact the sterile swab with the tonsils, pharynx, and any other potentially affected area, avoiding the tongue and buccal walls. A tongue depressor can facilitate this maneuver. Once sampled, the swab is placed in its container, properly labeled,
Understanding Neurons, Synapses, and Sensory Systems
Relations Function
The ability to capture pair changes or stimuli in the environment and respond if necessary.
Neurons
Santiago Ramon y Cajal concluded that the nervous system comprised independent cells, or “neurons.” His work earned him the Nobel Prize in 1906 and led to the neuron theory. Neurons are special cells with a common pattern:
- A central, enlarged part (soma or cell body). This contains the core and most cellular organelles.
- A unique, often enormously long prolongation, the “axon.” It has
Nutrition and Digestion: Key Concepts Explained
Regulatory Nutrients
These are compounds our bodies cannot produce themselves. They control the numerous chemical reactions in a cell.
Vitamins
We need vitamins because our body cannot synthesise them, so they need to be ingested with food.
Characteristics of a Balanced Diet
A balanced diet must provide enough calories and the right amount of essential nutrients. Ideally, 55% of calories should come from carbohydrates, 30% from fats, and 15% from protein. Animal protein should not exceed 40% of the total
Read MoreUnderstanding Pregnancy: From Conception to Childbirth
Pregnancy: From Conception to Childbirth
Pregnancy is the time that elapses from the fertilization of the ovum until birth. It takes about 38-42 weeks in a normal position. At 9 weeks of gestation, it is called an embryo (4cm and 5g). From September, it is called a fetus.
Placenta
The placenta is the organ through which metabolic exchanges take place between the fetus and the mother. It acts as a source of nutrition and respiration and releases hormones for gestation.
Changes in Pregnant Women
- Menstruation
Diagnostic Tests and Imaging Methods for Disease Detection
Diagnostic Tests: Detecting Disease in the Body
Diagnostics play a crucial role in identifying diseases and monitoring their progression. Accurate diagnostic reports are essential for effective treatment. Diagnostic procedures include:
- Physical Examinations: Assessing vital signs like blood pressure, heart rate, body temperature, and performing auscultation (listening to internal sounds).
- Blood Tests: Analyzing blood samples to detect infections (via leukocyte counts) and measure cholesterol, glucose