Human health and disease is the simplest and scoring chapter in NEET. Every year almost 3-4 questions are asked from this chapter in NEET and the level of questions is relatively easy as compared to other important chapters of biology. The candidates need to understand the theory of the chapter from NCERT book and refer to all the examples that are mentioned in NCERT because most of the questions from Biology are based on the NCERT book.

• The overall weightage of Biology in NEET 2020 is 50%, out of which this chapter holds the weightage of around 5 to 7%. 
• However, every chapter in biology is equally important to score good marks and thus candidates need to divide their time effectively amongst various chapters. 

NEET Biology SyllabusNEET Admit Card NEET Exam DatesNEET Exam Pattern

Read the article to know more about definitions of important topics from this section, previous year solved sample questions, some common mistakes that you should avoid to score well, and much more. 

Must Read: 

• NEET Study Notes for Molecular Basis of Inheritance
• NEET Study Notes for Biological Classification
• NEET Study Notes for Reproduction
• NEET Study Notes for Ecosystems

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Human Health and Disease –Types of Diseases

Human beings suffer from various diseases, which are caused due to genetic defects, infections or even an unhealthy lifestyle can result in causing these diseases.

These kinds of diseases are divided into two types:

Congenital Diseases: These disses are present inside human bodies from birth, the reason to these kinds of diseases include gene mutation, environmental effects, or chromosomal aberration. Chromosomal and gene defects can be transferred from one generation to another, a few example of Congenital diseases include colour blindness, Turner’s syndrome, Down syndrome, and much more.

Acquired Diseases: These diseases are acquired during a lifetime. Types of acquired diseases include:

• Infectious or communicable disease: that can be transferred from one person to another
• Non-communicable disease: These diseases don’t spread further by infection
• Deficiency disease: These diseases are caused in case there is some deficiency of an important nutrient, enzyme or hormones inside a human body.
• Allergies: hypersensitivity to foreign substances like pollen, dust mites, etc. results in causing allergies.

Sample Question

Question: Degenerative diseases are those that occur due to

• Malfunction of hormones
• Degeneration of tissues
• Malfunction of certain body organs
• Degeneration of the infected organs

The correct answer is C

Question: What are 'Pathogens'

• Substances produced against any disease causative
• The chemical substances that are produced to kill the parasite animal
• Disease spreading factors
• Cells which kill the parasites

The correct answer is C

Question: Sickle cell aneamia is quite common in South Africa, the reason to this is:

• Change in beta-chain of hemoglobin
• More population of house flies
• Change in alpha-chain of hemoglobin
• Change in gamma-chain of hemoglobin

The correct answer is A

Question: ‘Bacillary dysentery' causes due to

• Salmonella
• Shigella
• Proteus
• Entamoeba

The correct answer is B

Question: 'Hemophilia' causes due to deficiency of

• ADH
• STH
• AHF
• ACTH

The correct answer is C

Question: Which test confirms the scarlet fever?

• Dick test
• ECG
• UTI test
• Widal test

The correct answer is A

Check Gujarat Board Released Question Banks for NEET

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Malaria - Cause, Symptoms, Transmission

Lots of people suffer from Malaria since past so thousands of years and is very serious disease that occurs in the tropical and temperate regions. Malaria was almost eliminated a few years back with the efforts of WHO and numerous National Malaria Eradication Programs started in the country, but unfortunately, it has appeared again. The causes and symptoms of malaria include:

a) Symptoms: The attack of malaria results in symptoms like yawning, tiredness, headache, and pain in the muscles. During the fever, the patient starts feeling chilly and shivers, and experience severe headache, nausea and high temperature of the body. After some hours, the body perspires easily and the patient witness a significant downfall in the body temperature. The same cycle will be repeated in case no medicines are taken on time. In chronic cases, patients witness general weakness and anaemia (paleness) which is mainly due to the large-scale destruction of red blood corpuscles.

(b) Cause: Main reason for the cause of Malaria is the toxins that are produced inside the human bodies by Plasmodium, malarial parasites.

(c) Transmission: The malarial parasites are passed from the person who is infected to healthy persons by Anopheles, female mosquito. The mosquito picks up the parasites with blood, on biting an infected person and when the same infected mosquito bites a healthy person, the same parasites migrate into the blood of a healthy person with the saliva. The saliva which eth mosquito injects before sucking up blood is now transferred to the healthy person.

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What are the kinds of Plasmodium?

There are four kinds of species that can result in causing different kinds of malaria inside human body.

• P. Vivax – This kind of malaria causes benign tertian malaria, and it attacks every third day. After 48 hours, the patient starts witnessing fewer and headache, is mild and seldom fatal. These types of species are easily found in the tropical and temperate regions.
• P. ovale – These kinds of species also causes benign tertian malaria, and they recurs every second day. These species are found in the countries like West Africa and South America.
• P. malariae –  It results in the occurrence of quartan malaria, which recurs every fourth day, after every 72 hours. These species are seen in both tropical and temperate regions, though they are not much common.
• P. falciparum – These species are able to cause three types of malaria including quotidian malaria, that cab attacks daily; malignant tertian malaria, that attack after every 48 hours, but is very severe and often fatal; and irregular malaria. These species are found in the tropical regions only.

The incubation period for malaria which is caused by Plasmodium vivax is almost 10-12 days.

The lifecycle of Plasmodium (malarial parasite)

• First of all, plasmodium enters inside the human body by the bite of female Anopheles mosquitos
• The infectious form is sporozoites, which comes from the saliva of female anopheles on biting humans.
• This form gets multiplies in the liver cells, attacks RBCs which results in RBCs rupture
• Haemozoin which is a toxic substance starts releasing
• The gametocyte produced in the human blood transfer to the mosquito when it bites the infected person
• Macro and micro gametocyte undergo fertilization, transformation and sporogenesis in the mosquito’s intestine and sporozoites are produced
• Sporozoites move to the salivary gland of mosquito and same cycle gets repeated

Sample Questions

Question: African sleeping sickness or Gambiense fever causes due to

• Leishmania
• Trypanosoma
• Entamoeba
• Trichomonas

The correct answer is B

Question: Tse-tse fly is a vector for sleeping sickness that transmits the infective stage of which of the following parasite

• Wuchereria bancrofti
• Leishmania donovani
• Plasmodium falciparum
• Trypanosoma gambiense

The correct answer is D

Question: Schuffner’s dots are related to

• Entamoeba histolytica
• Leucocytes of frog
• RBC of man
• Epithelium of stomach of mosquito

The correct answer is C

Question: “Amoebiasis” or amoebic dysentery is caused by

• Trypanosoma histolytica
• Entamoeba histolytica
• Entamoeba gingivalis
• Plasmodium vivax

The correct answer is B

Question: The parasites of malarial can be obtained from a patient

• when the temperature comes to normal
• an hour before an increase in the temperature
• few hours post the temperature reaches to normal
• when the temperature rises with rigor

The correct answer is C

Check Detailed NEET Biology Exam Pattern

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What is immunity?

The ability of the body to stay protected and fight against any pathogen or foreign bodies is being referred to as immunity. If we have a strong immune system, then we can easily defend our body from all kinds of infection

The Immune System

• Human body’s ability to protect itself from all kinds of foreign bodies such as toxic substances, bacteria, virus, etc. which enter the body.
• The science which deals with different phenomena of immunity, induced sensitivity and allergy is referred to as immunology.
• Immune Response- A line of defense- It includes producing antibodies and generating specialized lymphocytes that acts against specific antigens.
• Antigens – Substances that stimulate the production of antibodies, whenever they are introduced into the body.
• Antibodies – Immunoglobulins (Igs) are produced in the body in response to the antigen or foreign bodies.

There are two main kinds of immunity which include Innate and Acquired or Adaptive or Specific Immunity.

There are two types of immunity:

• Innate immunity: This kind of immunity is present at the time of birth. There are 4 types of barriers that are present inside our bodies in the form of defense mechanism.
• Physical barriers: skin and mucous coating of the epithelial lining of respiratory, gastrointestinal and urinary tract

Sample Questions

Question: Immunity is acquired in case an infection is

• active immunity
• Passive immunity
• Innate immunity
• Both B and C

Correct answer: (a)

Question: Increase numbers of asthmatic attacks in some seasons is due to to

• Inhalation of seasonal pollen
• Heat and humidity
• Low temperature
• Eating preserved fruits

Correct answer: (a)

Question: Inflammation reaction is brought about by

• Plasma cells
• Mast cells
• Macrophages
• Adipose cells

Correct answer: (b)

Question: Inflammatory condition in allergy is mainly due to the release by mast cells of

(a) Antibodies

(b) Antigens

(c) Histamine

(d) All the above

Correct answer: (c)

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What are the kinds of Sexually Transmitted Diseases?

Acquired Immune Deficiency Syndrome (AIDS)

AIDS is a disorder of a cell-mediated immune system in the human body. A person suffering from AIDS witnesses a significant reduction in the number of helper T-cells that stimulate antibody production by B-cells. The results of it, leads to the loss of natural defense against protecting from viral infection. The main cause of AIDS is a virus named HIV (Human Immunodeficiency Virus) that was first discovered in 1984 by American and French scientists independently.

AIDS is the main sexually transmitted disease; semen contain the virus, but more likely an infected lymphocyte does,

Symptoms of AIDS: the entire HIV infection is segmented into 3 stages.

• Asymptomatic Carrier: Only 1%-2% of the newly infected people will have mononucleosis similar symptoms including fever, swollen lymph glands, chills, aches, and an itchy rash. These symptoms disappear on its own and there are no other symptoms for 9 months or longer.
• AIDS-related complex (ARC): It is the most common symptom of ARC, which results in swollen lymph glands in the neck, armpits, or groin and it remains same for almost 3 months or more.
• Full-Blown AIDS: It is the last stage, where there the patient witness significant weight loss and weakness due to persistent diarrhea.

Main causes of AIDS include:

The infection mostly spread:

(a) By sexual intercourse, vaginal and anal

(b) It can transfer from infected blood, donated semen and organs, or blood products.

(c) In case contaminated needles are used:

(1) While treating the patients

(2) When drug abusers share the same needles

(d) From an infected mother to her child:

(1) Across the placenta before birth

(2) While the baby passes through the birth canal

(3) Might be due to breast milk

AIDS Prevention

Shaking hands, swimming in the same pool, hugging, social kissing, coughing or sneezing, etc. are not the reasons of the transmission of the AIDS virus. You will not get AIDS from inanimate objects like telephones, toilets, doorknobs, office machines, or household furniture. HIV has been isolated from semen cervical secretions, lymphocytes, plasma, cerebrospinal fluid, tears, saliva, urine and breast milk. The secretions that can transfer AIDS include infectious like 

semen, cervical secretions, blood and blood products

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Cancer and its types

Cancer is an abnormal and non-controlled division of cells, which are referred to as cancer cells. They invade and destroy the surrounding tissues inside the human body. Mostly Cancer is explained as an uncontrolled proliferation of cells with no any differentiation.

• Neoplasms or Tumors: A neoplasm (new growth) is a mass of tissue that grows exceeding the normal, in fact, they grow in an uncoordinated manner and continues to grow after the initial stimulus has ceased. Tumors are divided into benign or malignant.
• Oncology: means the study and treatment of tumors.

Types of Tumors

There are two kinds of tumors including:

• Benign Tumor (Nonmalignant Tumor): These tumors remains limited to the site of its origin and don’t spread to other parts of the body. These tumors results in causing limited damage to the body.
• Malignant Tumor (Cancerous Tumor): Initially they grows slowly showing no symptoms. The starting stage is called the latent stage. But the tumor later grows speedily and go beyond adjacent tissue and enter the blood and lymph. If this happens, the cells move to other sites in the body and they divide. It is metastasis.

Types of Cancer (Types of Malignant Tumors)

Malignant tumors are divided into three main types based on the cell type from which they arise.

• Carcinomas: This type is mainly obtained from epithelial cells which include cervical cancer, breast cancer, stomach cancer, skin cancer, brain cancer, lung cancers, etc.
• Sarcomas: The cancer is located in connective and muscular tissues derived from mesoderm. It result in bone cancer, tendons, adipose tissue, lymphoid tissue and muscles. Osteoma is the term used to explain the cancer of bones.

Read How to Utilise Lockdown Period for NEET Preparation

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Important topics in Human Health and Diseases

To start preparing Biology for NEET 2020, it is important to revise the important topics first and have clear and accurate information about their weightage, the best books to refer and do more previous year sample papers. Some of the important topics include:

• Types of Diseases
• What are the Common Infectious Diseases in Humans
• What is the lifecycle of Plasmodium (malarial parasite)
• Difference between Active and passive immunity.
• Immune System in The Body
• HIV Virus Replication Cycle

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Previous Year Solved sample questions

Question: Immunosuppressants such as _________ help prevents transplanted organs from being rejected in recipients.

• Thrombin
• Cyclosporine
• Aspirin
• None of the above

The correct answer is Thrombin

Question: B & T lymphocytes are produced in the bone marrow; but T lymphocytes travel to the ______ and mature there.

• Spleen
• Thymus
• Pituitary gland
• Adrenal gland

The correct answer is Thymus

Question: Which is the largest in children, but with the onset of puberty, it shrinks and replaced by fat.

• Thymus
• Hypothalamus
• Parathyroid gland
• None of the above

The correct answer is Thymus

Question: Where Ascaris lumbricoides species of parasitic roundworm live?

• Humans
• Grasshoppers
• Pigs
• None of the above

The correct answer is Humans

Question: Which diseases is eradicated?

• Smallpox
• Rinderpest
• Polio
• All of the above

All are correct

Question: A kind of injury resulting in premature death of nearly all cells in a tissue or organ through autolysis is known as

• Neurosis
• Necrosis
• Apoptosis
• Cellular senescence

The correct answer is Necrosis

Question: Hypochondria is also referred as:

• Health anxiety
• Sleep apnea
• Hypnagogia
• Narcolepsy

The correct answer is sleep apnea

Download NEET Practice Papers

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Some Tips to Follow during Preparation

The most important part to prepare for NEET is to refer to the good and reliable study material that can help you to get familiar with the latest exam pattern, weightage of questions, etc. while preparing for the NEET, it is important to refer to the right NEET study material that can help in preparing for the exam. The aspirants can get assistance from their teachers and toppers before buying books. Some of the best NEET biology preparation books that can help aspirants to get good marks in their exam include:

• Objective NCERT at Your Fingertips for NEET
• Elementary Biology by Trueman
• AC Dutta for Botany
• Books by T.L Rayar
• 11th and 12th NCERT textbooks

Create a study Timetable

A well-prepared timetable can help the students in sticking to their study routine and allow them to focus on their weaker sections. By creating a plan and adhering to the same, the NEET aspirants can develop a seriousness and discipline. Some of the easy steps that candidates can follow while preparing a NEET time table to study biology.

• Get a calendar and a diary
• Make your priorities
• Prepare a daily study routine, and ensure that you are spending enough time preparing the biology section as well.
• Take care of your health
• Don’t sleep during your studying time
• But this doesn’t mean that you compromising with your sleep

Doing more objectives questions based on NCERT will help the students in having an understanding of the chapter and always solve questions with a fixed time limit. In Biology, while practicing, make sure that you are not spending more than 30–40 seconds on each question as it is enough time. Making a time table will help you to solve more questions and will increase your speed and accuracy as well. Solve previous year questions and you can learn to answer to standard questions that repeat frequently in NEET.

Read More Study Plan and Timetable for NEET 2020

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Some of the common mistakes that candidates must avoid

• Not adhering to the time table. Candidates must follow the timetable strictly so that they can get a good score in the exam.
• There is no need to follow a hectic schedule or study for extended hours, as it might affect your retention power.
• Most of the biology questions come from NCERT textbooks only, so ignoring the same can result in losing your scores. Check NEET 2020 Important Books
• Don’t refer so many books, rather you must study from one book at a time. Else you will get confused and will mess up everything you learned so far.
• Don’t ignore any chapter in human health and diseases, even a single page needs to be studied and revised properly.

It is important to stick to the time table and follow the above-mentioned preparation tips that can help to get a good rank in NEET Exam. Also, at the same time, it is important to avoid all the mistakes that can lower your scores.

Medical UG aspirants need to do NEET Biology Preparation by considering these tips and tricks that help them to achieve the best possible results. Stay focused and best of luck for the upcoming NEET exam.