Topics in BiologyTypes of Desert and their Characteristics Characteristics of Tropical Rainforest Swamp Forest: What are Swamp Forests? Characteristics of Swamp Forests Savanna: Savanna and Grassland explained Savanna - Types of Savanna Tropical Savanna and Temperate Savanna with their Characteristics Introduction to Biomes: What is a Biome? Importance of Swamp Forests Swamp Forests - Types of Swamp Forests Ecology - Ecological Concepts explained Biology: What is Biology? Are Viruses Living Organisms? Differences Between Bone and Cartilage Skeleton: Functions of the Human Skeleton Bone: Type and Classification of Bones based on Shape Skeletal Material: Cartilage and its Functions Cartilage: Types of Cartilage Components of the Ecosystem What is Ecology? Branches of Ecology Ecosystem: What is an Ecosystem?
Academic Questions in Biology
Which of the following is a category of long bones?
The end product of photosynthesis is _____.
The above diagram illustrates a _____.
The living cells that makes up cartilages are called _____.
Which of the following statement is incorrect with regards to chitin?
Which of the following is NOT a function of the human skeleton?
Organisms that manufacture their own food through the help of sunlight or chemicals are best referred to as _____.
Organisms that begins a food chain and also manufacture their food through photosynthesis are best referred to as _____.
One of the characteristics of every living organism is their ability to feed. This process of feeding is what nutrition entails. In fact, it is one of the basic characteristics of living organisms.
Nutrition can be defined as the intake of food or nutrients by an organism; to be used for its growth, repair and every other necessary process for the orgnism's survival.
Regarding nutrition, an organism will either manufacture its own food or depend on readymade food. For this reason, the mode of nutrition can be grouped into two major classes.
The modes of nutrition are:
In this article, we will explain the processes involved in autotrophic mode of nutrition.
In autotrophic nutrition, organisms are able to manufacture or produce their own food.
Organisms that manufacture their own food are referred to as autotrophs.
Autotrophic nutrition can be put into two groups; these are:
Photosynthetic nutrition requires that organisms are able to manufacture their own food by utilizing carbon(IV)oxide (CO2) and water (H2O) in the presence of sunlight. This process is known as photosynthesis.
Note: All green plants photosynthesize.
Photosynthesis can be defined as the process whereby green plants manufacture sugars (food) by utilizing carbon(IV)oxide (CO2) and water (H2O) in the presence of light energy (sunlight); while giving off oxygen (O2) as a bye product.
The equation below expresses the definition of photosynthesis.
6CO2 + 6H2O -> C6H12O6 + 6O2
- CO2 = Carbon(IV)oxide
- H2O = Water
- C6H12O6 = Sugar
- O2 = Oxygen
Although not seen on the equation; Light energy and Chlorophyll are also involved (necessary) in the photosynthetic reaction.
Photosynthesis occurs in a plant’s leaf. The leaves of plant contain an organelle called chloroplast.
The chloroplast houses the chlorophyll .
The chlorophyll gives the plant’s leaf its green coloration. Also, it is the chlorophyll that traps sunlight energy.
Note: Photosynthesis and Reproduction are two entirely different processes in plants. For instance, sexual reproduction in plants take place in the flower while photosynthesis occurs in the leaf.
An endothermic reaction is a reaction that takes in heat from its surroundings.
Photosynthesis is therefore an endothermic reaction since it requires sunlight energy.
Note: It isn't every stage in the process of photosynthesis that requires sunlight.
Photosynthetic reaction is put into two stages or reaction. These are:
This stage of photosynthesis occurs in the presence of sunlight. (That is; during the day).
The chlorophyll (present inside the chloroplast in the plant’s leaf) traps the light or solar energy.
This trapped light energy is used for breaking down or splitting water molecules into hydrogen ion (H+) and hydroxyl ion (OH-).
The process of splitting water into hydrogen ion (H+) and hydroxyl ion (OH-) in the presence of sunlight is referred to as the photolysis of water. The equation below shows this process:
4H2O -> 4H+ + 4OH-
Note: A co-enzyme called NADH is reduced to NADPH. ATP is formed during this process.
- NADH means Nicotinamide Adenine Dinucleotide
- NADPH means Nicotinamide Adenine Dinucleotide Phosphate
- ATP means Adenosine TriPhosphate
The formed hydroxyl ion is further converted into water and oxygen as shown in the equation below.
4OH- -> 2H2O + O2
Note: The oxygen given off as a bye product of photosynthesis comes from the light stage of photosynthesis.
The diagram below explains both the Light and Dark stages of photosynthesis.
Image Credit: ESA
Note: The sun is regarded as the ultimate source of energy. This is a statement of fact because the process of photosynthesis depends on it (sunlight energy).
Without the sun, there will be no green plants on earth and without green plants, there will be no animals. (There will be no flow of energy as seen in food chain).
This stage of photosynthesis occurs in the absence of light. (That is; at night).
During the dark stage, The ATP (which is energy itself) is utilized; as carbon(IV)oxide is taken in (through the stomata of the plant’s leaf) to react with the hydrogen ion (4H+) from the light reaction.
After a series of step by step reaction (with each step controlled by a specific enzyme); sugar (which is food) is formed.
The dark reaction is shown in the equation below:
4H+ + CO2 -> C6H12O6 + H2O
Note: C6H12O6 is the chemical formula for simple sugar.
Think of the stomata as an opening in the plants' leaf where gases enter and exit the plant.
Note: The sugar produced in photosynthesis occurs in the dark stage or reaction.
All green plants, blue-green algae, spirogyra and some protists carry out photosynthesis.
Organisms that manufacture food in a chemosynthetic manner do not require sunlight energy; rather chemicals are utilized here.
Chemosynthetic organisms (also referred to as Chemotrophs) synthesize their food from the oxidation of simple inorganic substances (chemicals) like carbon(IV)oxide (CO2), Ammonia (NH3), Nitrite(NO2) and water (H2O).
Note: Think of oxidation as a chemical reaction that involves oxygen (O2).
Some bacteria like Nitrosomonas and Nitrobacter make use of chemosynthesis in the manufacture of food. This is shown in the equation below:
i. Nitrosomonas will convert Ammonia (NH3) to Nitrite (NO2)
2NH3 + 3O2 -> 2HNO3 + H2O + Energy
ii. Nitrobacter will convert Nitrite (NO2) to Nitrate (NO3)
HNO2 + O2 -> HNO3 + Energy
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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.
Amazing facts in Biology
Male Seahorses actually give birth to their young ones, NOT the female
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
NOTABLE POINTS IN Biology
For a thing to be considered Living, it must possess all the Basic Characteristics of Life. These include:
Irritability or Sensitivity
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
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:
The term Biology originated from two Greek words. They are:
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:
The above listed points are often regarded as the basic characteristics of life. You can memorize them using the acronym (MR. NIGER DAC).
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