Red Blood Cells and Hemoglobin

len Alfred Ajibola - Fri, 14th June, 2019 @ 21:28: PM

Topics in Biology

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Academic Questions in Biology

Please check out our Test Your Knowledge page to see all Questions and Answers

Which of the following is NOT a part of the wrist bones (or carpal bones)?

  • A. Cuboid
  • B. Scaphoid
  • C. Hamate
  • D. Triquetral
  • E. Pisiform
  • F. Trapezium

The statements below are true concerning arteries except _____.

  • A. The arterial wall has 4 layers

  • B. Tunica Adventitia is the outermost layer of an artery

  • C. Aorta is the largest artery in the human body

  • D. Pulmunary artery conveys deoxygenated blood

  • E. Internal bleeding will occur when a deeply located artery is broken

  • F. Arterial vascular disorders are worsened in people with diabetes and renal failure

The following statements are true concerning blood vessels except _____.

  • A. They are comprised of arteries, veins and capillaries

  • B. Problems associated with blood vessels are called vascular disorders

  • C. All veins carry blood towards the heart

  • D. Capillaries are found at cellular level

  • E. Arteries usually divide to form arterioles

  • F. Arterioles give rise to capillaries

Food Pyramid - Len Academy

The above diagram shows a _____.

  • A. Food Chain

  • B. Food Web

  • C. Food Flow

  • D. Food Energy

  • E. Food Pyramid

  • F. Food Hierarchy

Anything that elicits a physiological response from an organism is termed _____.

  • A. Response

  • B. Irritability

  • C. Adaptation

  • D. Competition

  • E. Stimulus

  • F. Action potential

Which of the following molecule is utilized directly as energy in the human body?

  • A. Glucose

  • B. Carbohydrate

  • C. Starch

  • D. Adenosine Mono Phosphate

  • E. Adenosine Di Phosphate 

  • F. Adenosine Tri Phosphate

Which of the following is not a basic characteristics of life?

  • A. Locomotion

  • B. Competition

  • C. Adaptation

  • D. Irritability

  • E. Nutrition

  • F. Death

The final organisms in a food chain are best referred to as _____.

  • A. Saprophytes

  • B. Parasites

  • C. Commensals

  • D. Decomposers

  • E. Tertiary consumers

  • F. Quatenary consumers



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Red Bood Cells and Hemoglobin:

When we reflect on some of the necessities of life, oxygen (O2) will definitely rank among the top.

Although oxygen makes up about 21% of the atmosphere, it is still enough to make earth a livable planet for its different inhabitant.

Please read on Layers and Composition of the Atmosphere here.

In humans, without the red blood cell and hemoglobin, atmospheric oxygen will be considered a waste because the various bodily cells, tissues and organs will not be able to utilize it for respiration.

Note: Breathing and respiration is NOT the same thing.

Breathing is simply when one inhales and exhales air. Everytime we breathe, oxygen is inhaled while carbon(IV)oxide is exhaled.

Respiration is the use of oxygen to break down food in order to generate energy in the form of ATP. ATP stands for Adenosine Tri Phosphate.

Please read on the Basic Characteristics of Life here.

Facts on Red Blood Cells and Hemoglobin

In order to make our explanation a little bit simpler, we will look at some of the facts pertaining the red blood cells and hemoglobin.

Below are some of these facts:

  • The red blood cell can also be referred to as an erythrocyte.

  • The red blood cells are one of the solid components of the blood; the others being white blood cells and platelets.
  • Note: Blood is actually a mixture of liquid (called plasma) and solid (called cells). Based on this fact, a blood can be dried and grounded to form a blood meal.

    Please read on how a mixture of Blood can be Separated into its various components here.

  • An average human being produces up to 2.5 million red blood cells per second.

  • Ordinarily, the blood is light/pale yellow in color. It is the red blood cells that actually give the blood its red coloration.

  • The red blood cell has the shape of a biconcave disc with a thickness of 2.5 micrometers at its edges and less than 1 micrometer at its center.
  • The image below illustrates the shape and diameter of the red blood cell:

Red Blood Cell - Len Academy

  • The red blood cell is very flexible; and as a result, it can squeeze through blood capillaries by altering its shape without destroying itself.
  • Note: Capillaries are tiny and microscopic blood vessels that operate at the cellular level.

    Think of a blood vessel as a pipe that carries blood within our body system.

    The other blood vessels are the arteries and veins.

    Read on the Layers of an Artery and Characteristics of Arterial Disorders here.

  • A mature red blood cell has NO nucleus. Instead, it contains hemoglobin within.

  • Some scientists are of the opinion that if the matured red blood cells had a nucleus, the nucleus would be damaged when the red blood cells attempt to pass through the blood capillaries. This damaged nucleus will result in the sudden death of the red blood cell.

  • Red blood cell has no DNA, RNA, mitochondria or any other organelle found in most cells. For this reason, it does not require energy to carry out its functions. This is true because the mitochondria (often referred to as power house of the cell) is absent.
  • Please read on various Interesting Facts for Students here.

  • In the early weeks of embryonic life, the red blood cells are produced in the yolk sac. They contain nucleus at this time.

  • During the 3rd to 8th months of pregnancy, the red blood cell is produced mainly in the liver.
  • The spleen and lymph nodes also produces some red blood cell during this period.

  • During the last month of pregnancy and after birth, the red blood cells are produced exclusively in the bone marrow.
  • Please read on all the 206 Bones of the Human Body here.

  • After age 20, the long bones of the human body stop producing red blood cells.
  • Examples of long bones are humerus (bone of the arm) and femur (bone of the thigh).

    During this period (after age 20), the red blood cells are now produced in the membranous bones.

    Examples of membranous bones are the vertebrae, sternum and ribs.

    Please read on the Types of Bone here.

  • The major function of the red blood cell is to transport hemoglobin. This implies that the hemoglobin is present inside the red blood cell.

  • It is the hemoglobin in the red blood cell that binds with oxygen to form oxyhemoglobin.
  • Note: The red blood cell has other functions too. For instance, they initiate the transport of CO2.

    The transport of Carbon(IV)oxide by the hemoglobin is made possible because it contain an enzyme called carbonic anhydrase which catalyzes the reversible reaction between carbon(IV)oxide (CO2) and water (H2O) to form carbonic acid (H2CO3). It is in this form that CO2 is transported back to the lungs for expiration.

  • The red blood cells bind more strongly to carbon(II)oxide or carbon monoxide (CO) when compared to the rate at which oxygen binds to hemoglobin. This is why death is very rapid in carbon monoxide poisoning.

  • Red blood cells are red when hemoglobin (present within it) is combined with oxygen to form oxyhemoglobin.
  • They become blue after the oxygen had been delivered to the body cells.

    Please read on some Amazing Facts in Biology here.

  • An average man has 5,200,000 red blood cells per cubic millimeter of blood.

  • An average woman has 4,700,000 red blood cells per cubic millimeter of blood.

  • Erythropoietin is a hormone that stimulates the production of red blood cells.
  • Erythropoietin is produced in the kidneys and an increase in its production is trigged during hypoxia.

    Note: Think of hypoxia as a condition where there is very little amount of oxygen in the blood; and as a result, the body tissues lack oxygen too.

    Please read on Homeostasis here.

  • Iron is vital in the formation of hemoglobin. This is why it is always present in blood capsules; and often recommended by medics for blood building.

  • The red blood cells have an average lifespan of 120 days after which they are destroyed by the liver and spleen respectively.

  • Anemia results when there is little or no hemoglobin in the blood.
  • Anemia will also occur when there are too few red blood cells in the blood.

  • Polycythemia is the presence of too many (excessive) red blood cells in the blood. This condition is seen in people that live in high altitude.
  • Note: The higher the altitude, the lower the atmospheric oxygen.

  • Polycythemia Vera (also called Erythremia) is when there are excessive red blood cells in the blood as a result of genetic aberration.

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Alfred Ajibola is a Medical Biochemist, a passionate Academician with over 7 years of experience, a Versatile Writer, a Web Developer, a Cisco Certified Network Associate and a Cisco CyberOps Associate.

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All babies are born with blue eyes

Research made at the University of Vienna suggested that yawning may play an essential role in cooling the brains

All voluntary and concious activity of right handed people are controlled from the left part or hemisphere of the brain

A snail can actually sleep for 3 years 😁

An adult human being is composed of about 60% water. In fact, a newly born baby is composed of about 80% of water. This will drop to 65% after a year and finally to about 60% as the child ages

Without saliva, food can never be enjoyed. Food becomes tasteless since saliva is needed to dissolve the chemicals present in food onto the tongue’s taste buds.

Saliva also contains an enzyme called salivary amylase or ptyalin which helps to digest cooked starch to maltose.

Maltose is a double sugar or disaccharide.

Please read on sugars here


For a thing to be considered Living, it must possess all the Basic Characteristics of Life. These include:

  1. Movement

  2. Respiration

  3. Nutrition

  4. Irritability or Sensitivity

  5. Growth

  6. Excretion

  7. Reproduction

  8. Death

  9. Adaptation

  10. Competition

Please read the explanations on all the Basic Characteristics of Life here

During strenuous exercises like sprinting or 🏃 running, your body may actually work in the shortage of oxygen. During this time, your body owes oxygen (called oxygen debt) and it must be replenished or repayed after the exercise is stopped. This is why you breathe excess of oxygen after you stopped the exercise.

This is the concept of anaerobic respiration

Food Chain - Len Academy

A food Chain is a diagram that shows the relationship between plants and animals within a habitat on the basis of how they rely on each other for food.

Note: Habitat is a place where an organism live. It is of three types:

  • Terrestrial (Land)
  • Aquatic (Water)
  • Arboreal (🌲 Treetops)

You can read on Food Chain here

The term Biology originated from two Greek words. They are:

  • Bios: means life.
  • Logos: means knowledge or to study.

Biology can therefore be defined is the study of life

Anything that has life is generally considered as a living organism (or organism) 🌱🐐🐓. All living organisms must be able to carry the following activities:

  1. Movement
  2. Respiration
  3. Nutrition
  4. Irritability or Sensitivity
  5. Growth
  6. Excretion
  7. Reproduction
  8. Death
  9. Adaptation
  10. Competition

The above listed points are often regarded as the basic characteristics of life. You can memorize them using the acronym (MR. NIGER DAC).

You can read on the introduction to Biology and the basic characteristics of life here

The gas used in the manufacture of food by plants is Carbon dioxide or Carbon(IV)oxide or CO2

Plants manufacture food through a process called photosynthesis.

Please read on photosynthesis here

Note: Plants are the only orgnisms that take away CO2 from the atmosphere