Circulatory and Excretory Systems: Functions and Anatomy
What is the Circulatory System?
The circulatory system is responsible for carrying the products of digestion and oxygen obtained through the respiratory system to all the cells of the body. It also collects waste products and takes them to the excretory system where they will be eliminated.
What Organs Form the Circulatory System?
It is formed by a central body called the heart and blood vessels (arteries, veins, and capillaries).
How is the Heart Shaped?
The heart is a hollow organ composed of muscle
Read MorePhotosynthesis: Energy Input and Factors Affecting It
Photosynthesis: A Unique Mechanism of Energy Input
Photosynthesis is a unique mechanism for energy input into the biosphere. Light is captured and converted into chemical energy in the form of organic matter, stored as carbohydrates, producing free O2. This process distinguishes the plant kingdom. It is influenced by the following factors: light, temperature, air humidity, water availability, carbon dioxide (CO2), and nutrients. Free oxygen in the atmosphere reaches 21%.
Historical Contributions to
Read MoreFemale Reproductive System: Anatomy and Function
Female Reproductive System
Ovarian Development and Function
The female reproductive system begins to form and function in utero at 20 days of gestation. Its activity is cyclical and lasts for many years.
Ovaries
The ovaries are almond-shaped organs that are initially pink but eventually shrivel and darken. Inside, there are many primary follicles, which, after a process, become Graafian follicles.
Fallopian Tubes
The fallopian tubes are two canals that connect to the uterus. They are broader at the ovarian
Read MoreBacterial Differentiation Techniques: Blood Agar, Catalase, Oxidase
Blood Agar
Blood agar differentiates bacteria based on what reaction?
Blood agar is differential. The medium contains 5% sheep red blood cells that are added to trypticase soy agar. It is a rich medium that allows many organisms to grow, and it is differential for the action of bacterial enzymes on red blood cells.
Shows different types of hemolysis.
Alpha, beta, gamma
Beta-hemolytic bacteria produce enzymes that are able to completely lyse red blood cells, which causes a clear transparent zone in the
DNA Replication, Transcription, and Translation Processes
DNA Replication
- At the origin of replication, DNA is unzipped by helicase. Single-strand DNA-binding proteins prevent the double helix from forming again.
- Primase adds RNA primers as a binding site for DNA polymerase.
- DNA polymerase adds nucleotides to synthesize the new strand of DNA at the 3′ end.
- Removal of primers by exonuclease.
- Filling the gap by DNA polymerase. The leading strand is synthesized continuously in the 5′ to 3′ direction, and the lagging strand is synthesized discontinuously in fragments
Sexual Reproduction, Vision Defects, and Human Biology
Advantages of Sexual Reproduction
In sexual reproduction, more variations are produced. Thus, it ensures the survival of species in a population. The newly formed individual has characteristics of both parents. Variations are more viable in sexual mode than in asexual mode. This is because, in asexual reproduction, DNA has to function inside the inherited cellular apparatus.
The Testes
The testes are the male reproductive organs that are located outside the abdominal cavity within a pouch called the
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