30 most important topics on biology

I am going to list 30 most important topics on biology. This topic is important for all streams of biology. Every student must give emphasis on those topics. Proper understanding is must on these topics. Most of the questions asked in all competitive exams which have biology as a part of syllabus on these topics. So students must have crystal clear concepts on these topics. Moreover, if the basics in this topic are clear then it helps in higher education. 

30 most important topics on biology

DNA replication:

It is a topic of genetics. Replication of DNA follows a mechanism. Most of the cases students feel it as a difficult topic and avoid it. But if you don’t have a clear concept on this topic then you will be stuck in a higher class. Eukaryotic and prokaryotic organisations follow different mechanisms for DNA replication. By this method DNA makes its copy during cell division. Genetic material duplicated by this method. So DNA replication is vital for cell division. It helps to transfer the genetic material from generation to generation. If you once understand it’s mechanism then it will be interesting to you. And it will help to understand more theory on genetics. 

Transcription:

RNA is formed from DNA by RNA transcription. Within the nucleus copy of RNA form from DNA. After the formation of RNA it goes through various processes. Then it comes outside the nucleus. It forms m-RNA that is messenger RNA. It carries the message or genetic information. For protein synthesis cells need m-RNA. And this m-RNA formation occurs inside the nucleus. Understanding of the mechanism how m-RNA formation occurs from DNA is essential for understanding genetics. Every student should have a proper understanding of the RNA transcription mechanism. Frequently asked questions on examinations from these topics. So from both points of view it must understand. 

Translation:

After formation of m-RNA it comes to cytoplasm. On cytoplasm it is necessary for protein synthesis. Protein synthesis from m-RNA in cytoplasm is known as translation. By this method with the help of ribosome m-RNA are decoded. Ribosomes read data on m-RNA and gather amino acids in order to form protein. Amino acids are arranged in sequence as per the sequence of ribonucleotides on m-RNA. Data for protein synthesis present on m-RNA. And ribosomes only can understand it. So if you want to understand how proteins are synthesized in a cell then you must understand the mechanism of translation.

Photosynthesis:

Producers can synthesis on their own body. They use raw inorganic substances to produce organic food. Green plants produce their food by the method of photosynthesis. They utilise sunlight, carbon dioxide and water to produce organic food. Not only food they also produce oxygen as a by product. Mechanism of photosynthesis needs understanding of a lot of biochemical reactions. Not only green plants, some microorganisms also perform photosynthesis. All living beings are dependent on photosynthesis. Either they are directly dependent or indirectly dependent on photosynthetic organisms. For understanding of photosynthesis you should carefully study the mechanism of photosynthesis. 

Respiration:

All living beings are made of cells. Cells need energy to maintain its structure. We know that energy comes from food. But for energy we need to oxidise the food molecules. In respiration food substance oxidised to produce ATP. Energy of food transfer to bond energy of ATP. So for energy oxidation must be required. Respiration is for that oxidation. Respiration provides vital energy. To sustain life, respiration is the most important process. In presence of oxygen or absence of oxygen both have different mechanisms. So if you want to understand how energy is generated in a cell you should refer to the mechanism of respiration. 

Digestion:

All living cells required energy and the energy comes from food. But in food the molecule present in complex form. Cell unable to utilise this complex form. Cell need simple form of molecule to utilise it. In digestion complex molecule break down into simple molecule. Then cell use the simple form of molecule. In digestion different complex molecule treated with different kinds of enzymes. Specially hydrolytic enzymes break down the macromolecule and macromolecules. So digestion of digestion of different kinds of molecules follow different kinds of mechanisms. Without digestion there is no importance of food. 

Excretion:

In cells during various biochemical reactions a lot of waste and harmful material is produced. Some of those chemicals are very harmful for cells. So these chemicals should be removed from the cell. Otherwise it will create different types of problems. Removal of these harmful substances from cells is known as excretion. In most of the cases these substances are nitrogenous in nature. Different organisms have different types of excretory systems to remove these harmful substances. When excretion does not work properly various types of problems arise. Different organisms have different types of excretory material also. 

Flora and Fauna:

In ecology there are two terms, flora and fauna. Term flora are used for all plants in the earth. And fauna is collectively used for all animals. For a better understanding of ecosystems we should study about flora and fauna. Everyday we find new species of plants and animals. So the number of flora and fauna is not fixed. Its number depends upon how much we know about them. Most of the species are unknown to us. Everyday we get introduced with different animal and plant species. In general flora contribute to the ecosystem. And fauna contribute to the ecosystem. 

Carbon Cycle:

In living cells most important components are carbon. Major components of biomolecules are carbon. Carbon present in earth and in living cells both. Cycling of carbon among lithosphere, atmosphere living cells is done by carbon cycle. By carbon cycle carbon  taken by living cells from nature is returned back to nature. If carbon cycles do not maintain property they all carbon content in nature will finish. Carbon cycles maintain the carbon balance between nature and living organisms. In general in living cells carbon occurs in organic molecules. But in nature it occurs as inorganic compounds in general.

Nitrogen Cycle:

Like carbon cycle it also essential to maintain the nitrogen balance in between nature and living cells. Nitrogen is present in different forms in soils, atmosphere and in living organisms. Most of the excretory products are also nitrogenous in nature. Nitrogen Cycle maintains the nitrogen pool of the ecosystem.  A cyclic process ensures the nitrogen balance in nature. These cyclic processes contain a series of biochemical reactions. So for understanding how nitrogen is recycled in nature you should study nitrogen cycle. In nature nitrogen is present in such a form which is not directly usable by living cells. So they undergo some biochemical processes to make it usable. 

Mitosis:

It is one type of cell division. Mitosis is known as equal division. In mitosis, divided cells have an equal number of chromosomes of the month cell chromosome. So it is known as equal division. For example, it makes a cell 2n to 2n and from n to n. It is responsible for increasing the number of cells. It increases the number of cells. It is responsible for growth of the organisms in multicellular organisms. In unicellular organisms it may work as a method of reproduction. Mitosis has several phases with specific characteristics. 

Meiosis:

It is commonly known as reducing division. In meiosis cell division daughter cells get half the number of chromosomes as that of the mother cell. For example it makes 2n to n. It is observed in general when gametes formation. Sometimes it helps to maintain alternation of generation. Specially in case of fungi it helps to maintain a state of chromosome in the cell. It is very important to understand gametogenesis. Meiosis has a great importance to reproduction of organisms. It is only one method of reproduction when there is no scope for vegetative reproduction. So if you want to understand how gametes are formed then you must understand meiosis properly.

Gametogenesis:

It is a very important process for sexual reproduction. The process of gametes formation is known as gametogenesis. When gametes are isogametes then there are only one type of gametes produced. When gametes are heterogametes then different types of gametes form in different mechanisms. In gametes formation cells are divided. This division may be mitosis or meiosis. It depends upon which type of gametes will form. After gametogenesis gametes participate in reproduction. Gametogenesis helps an organism to maintain its continuity in nature. So to understand reproduction properly you need to understand gametogenesis properly. 

Human Nervous System:

In physiology it is a most important topic. Nervous system comprises brain, spinal cord sensory organs. In this topic we can know everything how brain works. How we can sense audio information, visual information and understanding about our environment. In nervous system we can know how brain can store memory and we can use it on its requirements. In nervous system we can know about the structure and function of neurons. If you want to understand how nerve impulse is generated in neurons then you must understand the electrochemistry of the nerve cell. 

Human Skeleton System:

The main support of vertebrates are skeletal systems made of bone. It is also an important topic in physiology. Here we have to study about different types of joints, bones of different body parts, cartilage, tendon, ligament. Anatomy of bone tissue is important to understand the bone structure. The Human Skeleton System has an important role in movement and locomotion of human beings. To understand different types of disease related to the skeletal system we must understand the whole skeleton system first. In competitive examination it is rare when questions not asked from these topics. It is a simple topic as compared to other topics in human physiology. 

Circulatory System:

In physiology it is linked to all other topics. Here we have to understand the structure and function of the heart. To understand heart pumping activity we need to understand how the heart pumps the body fluids continuously. Not only heart here we have to study about arteries and veins. To understand various diseases related to the cardiovascular system we need basic understanding about the circulatory system. If you want to know why heart muscles are able to work continuously then you have to study cardiac muscle. For blood transfusion we need proper knowledge about various types of blood groups.

Cardiac Cycle:

Our heart pumps blood in a regular manner. It consists of alternate contraction and expansion of atria and ventricle. It is a series of systole and diastole. In cardiac cycles we study the time required for one complete blood circulation in our body. Here we have to study about the time required for a unit systole and diastole. We can predict various disorders related to the heart by observing the time to each action in the heart. Time interval of cardiac cycle indicates the condition of the heart. Any abnormal time interval warns us about a specific disorder. 

Histology:

Some students find it difficult to understand the histology. As it is generally observed in microscopes. So sometimes it takes time to understand properly. Histology of major human tissue is very important to understand its structural organisation. For example histology of thyroid gland, histology of parathyroid gland, histology of pancreas, histology of intestine, histology of liver, histology of kidney, histology of ovaries, histology of testis are very important. In histology there are some special techniques for making the tissue ready for staining, section, fixing etcetera. There are different types of staining processes for different types of tissues. 

Biomolecules:

Living cells are made of different types of biomolecules. In nature generally biomolecules occur as a polymer of simple organic molecules. Simple biomolecules are condensed to form polymers. For example lipids are made of glycerol and fatty acids, proteins are made of amino acids, disaccharide and polysaccharide are made of monosaccharides. Biomolecules make the structure of cells. To maintain different types of cellular activity biomolecules play important roles. To understand the structure of cell organelles we should study about the biomolecules first. Chemical formulas of biomolecules give us a general idea about the nature of the biomolecules.

Cells:

Without understanding the cell theory it is impossible to study biology. There are different types of cells known in our nature. Depending upon presence of nucleus, shape, size, functionality cells are categorised in different categories. To understand how cells are formed and how they perform various activities we should study about the structure and function of cells. In a cell there are different types of cell organelles for different types of functions. Each cell organelles have their own specific role in the activities of the cell. So activity of a cell can be explained by functionality of its organelles. Cells with common origin and function generally form a tissue which can perform a specific type of activity. 

Genetics:

cells contain nuclei. In the nucleus DNA stores the data about the direction for the cell. When a cell divides DNA, the parent cell transfers to the daughter cells. So the qualities of the parent cell transfer to the daughter cells. That is why in most of the cases we can observe similarities between parent and siblings. All of these follow some rules. These rules are known as genetics. In genetics we study how cell transfer its genetic material from generation to generation. 

Mutation:

It is any changes to the genetic material. It may be expressed outside. It may be hidden. Mutation means change in genetic material. It may be beneficial sometimes. Sometimes it becomes harmful for the organism. Beneficial mutations help the organism in different ways. But harmful mutations damage the organism in different ways. Mutation may be spontaneous. It may be artificial also. Various outside factors are sometimes responsible for mutation. For example ultraviolet rays, any harmful chemicals may cause mutation. Mutation is required for new quality in organisms. Mutation helps to adapt in the nature of mutation that occurs in the favour of the environmental conditions.

Ecology:

In modern day it is a very important topic. We have to understand the situation around our environment. In ecology we study various components of the environment. How various components of the environment are dependent on each other. In ecology we can understand the role of all components in the environment. It also helps us to understand various environmental problems. We can resolve environmental problems when we have the knowledge of the environment. Major topics of ecology are ecosystem, food chain, food web. We should be aware about various current ecological issues. For example global warming, ozone layer depletion, air pollution, sound pollution, soil pollution, water pollution etcetera.

Difference between Prokaryotic and Eukaryotic cells:

On the basis of presence of ideal nucleus we can divide cells into two categories- Prokaryotic and Eukaryotic. In prokaryotic we can see primitive type nuclear materials. In eukaryotic cells we can observe advanced types of nuclear materials. Organisation of nucleus in eukaryotic cells are very advanced. In eukaryotic nuclear membrane and ideal nucleus present. In eukaryotic cell membrane bound cell organelles are present. In prokaryotic cells cell organelles are not membrane bound. 

Adaptation:

If one organism wants to live in adverse conditions, then it must show any modifications. The modification which helps the organism to sustain in adverse conditions is adaptation. In evolution adaptation has a great role. Adaptation helps organisms to win in natural selection. In specific conditions organisms with a specific character get advantage over other organisms. In different adverse conditions different types of adaptation are found. In water plants and animals they show some specific adaptation which helps them to overcome various adversity in water. Similarly in dry regions the plant and animal show different types of physiological, morphological adaptation. 

Classification:

In nature there are different types of organisms. But if we observe them carefully we can find similarity and dissimilarity among them. On the basis of similarity and dissimilarity we can categories them into different groups. It helps to study all organisms in a proper way. In a group all organisms show some similarities. There is a minimum one dissimilarity between two different groups. 

Human Health and Disease:

It is a very important topic for specially different types of medical entrance examinations. In this topic we study about different types of disease in human beings, their causal agents, symptoms, prevention, overview about treatment. As causal agents we have to study about different types of microorganisms. We have to understand about different general viral, bacterial, protozoan, fungal diseases in humans.

Birth Control:

Now overpopulation is a very important issue. To resolve it we should control the population. Awareness about birth control among common people would have to control population. Different types of techniques have evolved to control birth. But most of the area is not aware about this overpopulation issue yet. So it is now a very important topic.

Biotechnology:

In different industries biotechnology is applied. In biotechnology we use knowledge about biomolecules and different types of microorganisms. So for proper use of biotechnology we should understand about various aspects of biology. Biotechnology helps us make possible things which were impossible in early times. In agriculture different types of genetically modified organisms are possible only due to biotechnology. In medicine insulin is prepared using biotechnology. Gene therapy, transgenic animals are possible only for biotechnology. 

Enzymes:

In cells enzymes are main factors for different biochemical reactions. If enzymes were absent then a single biochemical reaction would take a very long time. But in presence of enzymes biochemical reactions occur in fractions of second. To understand how enzymes work we need to study the structure and properties of enzymes. 

Conclusion:

I listed in this post not only the most important topics on biology there are many other topics which are also important. But these topics generally most of the students feel difficult to understand. So they should give emphasis on those topics. As these topics are the backbone of my branch of biology. So if they compromise about the understanding of base on these topics they may face more problems on higher education. If you want to know more you can search it on Google, YouTube, Wikipedia.