BPSC TRE 4.0 Science Important Questions, Key Concepts

The BPSC TRE 4.0 Science paper is largely NCERT-based and question-driven, focusing on direct factual MCQs, concept-clarity questions, and match-the-following formats. BPSC TRE 4.0 Science important questions are designed to help candidates quickly identify high-weightage areas, frequently asked facts, and exam-relevant concepts from the Science syllabus. 

Students should focus on these repeated exam themes for efficient revision and better accuracy in the actual BPSC TRE 4.0 Examination.

Human Digestive System & Nutrition

Understanding the human digestive system and nutrition is fundamental for competitive exams. The human digestive system is a group of organs that ingests food, digests it into simpler substances, absorbs nutrients, and eliminates waste, supplying energy and materials necessary for growth and maintenance of the body.

Nutrition is the process by which organisms take in food and utilize nutrients for energy, growth, repair, and regulation of body functions.

Human Dentition and Tooth Structure

Human dentition showcases specialized teeth for varied functions. The presence of different types of teeth (incisors, canines, premolars, molars) is known as a heterodont condition, found in mammals like cats, rabbits, and bats. A notable example of specialized dentition is the elephant tusk, which is an enormously enlarged upper incisor.

Types and Numbers of Teeth

• Wisdom Teeth: Humans typically have four wisdom teeth, which are the last molars to erupt.

• Milk Dentition vs. Adult Dentition: The teeth absent in the milk (deciduous) teeth of a child but present in an adult are the premolars.

• Carnassial Teeth: These are modified teeth for tearing flesh, functionally analogous to canines.

Dental Formula and Tooth Count

The human dental formula for one half of the jaw is 2-1-2-3 (2 incisors, 1 canine, 2 premolars, 3 molars). To determine the count for a full jaw, this formula is doubled:

• Incisors: 2 x 2 = 4

• Canines: 1 x 2 = 2

• Premolars: 2 x 2 = 4

The resulting tooth count for a full jaw is 4, 2, 4, 6.

Tooth Composition and Health

• Enamel Hardness: The element responsible for the hardening of tooth enamel is Fluorine. While calcium is crucial for strong teeth, fluorine specifically imparts exceptional hardness.

• Hardest Constituent: The enamel is the hardest substance in the tooth and the entire human body.

• Pulp Cavity Lining: The pulp cavity is lined by cells called Odontoblasts.

• Diastema: This term refers to a significant gap between teeth, often caused by the congenital absence of certain teeth.

Human Dentition and Tooth Structure Important Questions

Q1. The presence of different types of teeth such as incisors, canines, premolars, and molars in humans is called:
A. Homodont condition
B. Diphyodont condition
C. Heterodont condition
D. Polyphyodont condition

Answer: C. Heterodont condition

Q2. Which of the following teeth are absent in milk dentition but present in permanent dentition?
A. Incisors
B. Canines
C. Molars
D. Premolars

Answer: D. Premolars

Q3. The hardest substance in the human body is:
A. Dentine
B. Cement
C. Enamel
D. Bone

Answer: C. Enamel

Q4. Which element is mainly responsible for the hardening of tooth enamel?
A. Calcium
B. Phosphorus
C. Fluorine
D. Magnesium

Answer: C. Fluorine

Macronutrients and Amino Acids

Macronutrients, proteins, carbohydrates, and fats are required in large quantities, providing energy and building blocks for the body.

Proteins, Carbohydrates, and Fats

• Body Growth: Protein is the most essential nutrient for body growth and the formation of new cells. Milk, eggs, and meat are excellent sources, with casein being the specific protein in milk.

• Monosaccharides: Glucose is a simple form of carbohydrate, classified as a monosaccharide.

• Energy Storage: When food intake exceeds energy expenditure, surplus energy is stored as fat and glycogen. The body can utilize this stored subcutaneous fat during prolonged periods of starvation.

• Location of Fat Storage: Fats are richly found and stored in adipose tissue.

• Energy Density: Fat provides more than double the calories per unit of mass compared to carbohydrates, making it the most energy-dense macronutrient.

• Glycogen Storage: Excess glucose is converted into glycogen and stored in the liver.

Amino Acids

Amino acids are the building blocks of proteins. They are categorized based on the body's ability to synthesize them.

• Essential Amino Acids: These amino acids cannot be synthesized by the human body and must be obtained from food. There are 9 essential amino acids for adult humans (Older textbooks might state 8, but modern NCERT guidelines confirm 9).

• Non-Essential Amino Acids: These can be synthesized by the human body; an example is Glycine.

• Semi-Essential (or Conditionally Essential) Amino Acid: Arginine is an example of a semi-essential amino acid.

• Most Complex Amino Acid: Tryptophan is a highly complex amino acid with a ring structure.

• Symbolic Representation of Amino Acids:

• F: Phenylalanine

• K: Lysine

• W: Tryptophan

Macronutrients and Amino Acids Questions

Q5. Which macronutrient is most essential for body growth and formation of new cells?
A. Fat
B. Carbohydrate
C. Protein
D. Vitamin

Answer: C. Protein

Q6. Excess glucose in the human body is stored mainly in the form of glycogen in the:
A. Kidney
B. Pancreas
C. Liver
D. Intestine

Answer: C. Liver

Q7. Which macronutrient provides more than double the energy per unit mass compared to carbohydrates?
A. Protein
B. Fat
C. Vitamin
D. Mineral

Answer: B. Fat

Q8. Fats are mainly stored in the body in:
A. Muscle tissue
B. Nervous tissue
C. Adipose tissue
D. Epithelial tissue

Answer: C. Adipose tissue

Q9. How many essential amino acids are required by adult humans according to modern NCERT guidelines?
A. 7
B. 8
C. 9
D. 10

Answer: C. 9

Q10. Which of the following is a non-essential amino acid?
A. Lysine
B. Tryptophan
C. Phenylalanine
D. Glycine

Answer: D. Glycine

Q11. Which amino acid is considered semi-essential or conditionally essential?
A. Glycine
B. Arginine
C. Lysine
D. Methionine

Answer: B. Arginine

Q12. Which amino acid is considered the most complex due to its ring structure?
A. Alanine
B. Glycine
C. Tryptophan
D. Valine

Answer: C. Tryptophan

Vitamins and Deficiency Diseases

Vitamins are organic compounds crucial for various life-sustaining functions, required in small quantities. They often act as coenzymes and are essential for health but do not provide energy. Most vitamins cannot be synthesized by the body and must come from the diet.

• Fat-Soluble Vitamins: A, D, E, K (A mnemonic to remember the fat-soluble vitamins is KEDA).

• Water-Soluble Vitamins: B-complex and C.

Specific Vitamins and Associated Conditions

• Vitamin A (Retinol): Essential for vision. Carrots are a prime source. Deficiency leads to Night Blindness (Nyctalopia).

• Vitamin B1 (Thiamine): Found in whole wheat bread. Deficiency causes Beri-beri.

• Vitamin B3 (Niacin / Nicotinamide): Deficiency leads to Pellagra, with symptoms including swollen lips, pigmented skin, and irritability.

• Vitamin B9 (Folic Acid): Essential for DNA synthesis and cell division. It is synthesized by intestinal bacteria and absorbed significantly.

• Vitamin B12 (Cyanocobalamin): Crucial for erythrocyte (red blood cell) development. Deficiency causes Pernicious Anemia. It is primarily absorbed in the ileum.

• Vitamin C (Ascorbic Acid): Abundant in citrus fruits. Deficiency leads to Scurvy. A diet lacking fresh fruits/vegetables, like only milk, eggs, and bread, puts one at risk for Scurvy.

• Vitamin D (Calciferol): Aids in calcium absorption and regulation. Deficiency causes Rickets in children and is linked to calcium deficiency.

• Vitamin E (Tocopherol): Deficiency can lead to sterility (infertility).

• Vitamin K (Phylloquinone): Essential for the synthesis of prothrombin, a key protein for blood clotting.

Here is a Comparative Chart of Vitamin Deficiencies:

A Hindi mnemonic to remember the chemical names for vitamins A, B, C, D, E, and K is "रथ एक टाफी": र (Ra) → R**etinol (Vitamin A), थ* (Tha) → Th**iamine (Vitamin B), ए* (E) → A**scorbic Acid (Vitamin C), क* (Ka) → C**alciferol (Vitamin D), टा* (Ta) → T**ocopherol (Vitamin E), फी* (Phi) → *Ph**ylloquinone (Vitamin K).

Vitamins and Deficiency Diseases Important Questions

Q13. Which vitamin deficiency causes Night Blindness?
A. Vitamin B1
B. Vitamin C
C. Vitamin A
D. Vitamin D

Answer: C. Vitamin A

Q14. Beri-beri disease is caused due to deficiency of:
A. Vitamin B1
B. Vitamin B3
C. Vitamin B12
D. Vitamin C

Answer: A. Vitamin B1

Q15. Pernicious anemia is caused due to deficiency of:
A. Vitamin B6
B. Vitamin B9
C. Vitamin B12
D. Vitamin C

Answer: C. Vitamin B12