1. Which one among the following statements is correct?
• The pulmonary artery carries deoxygenated blood from the heart to the lungs, while all other arteries, including the aorta, carry oxygenated blood from the heart to the rest of the body.
• Similarly, veins generally carry deoxygenated blood back to the heart, except for the pulmonary vein, which carries oxygenated blood from the lungs to the heart.
2. A surge of which hormone stimulates ovulation in human females?
A surge in luteinizing hormone (LH) triggers ovulation in human females. This hormone is released by the pituitary gland and causes the mature egg to be released from the ovary, marking the process of ovulation.
3. The shape of chromosome is clearly visible at
The shape of the chromosome is clearly visible during Metaphase.
During metaphase, chromosomes align at the cell's equatorial plate, making them distinct and easy to observe under a microscope.
4. Largest flower Rafflesia is
Rafflesia arnoldii, the world's largest flower, is a total root parasite. It grows by taking nutrients and water from the roots of a host plant, instead of producing its own food.
5. A species inhabiting different geographical areas is known as
Allopatric species are those that are geographically isolated from each other, preventing interbreeding. This isolation typically leads to speciation, where populations evolve into different species over time.
6. Higher plants take up nitrogen as
Higher plants primarily take up nitrogen in the form of nitrates (NO₃⁻) and ammonia (NH₃). These forms of nitrogen are absorbed from the soil and are then used in various metabolic processes to form amino acids, proteins, and other essential compounds.
7. Which of the following has the largest number of chromosomes?
Pteridophytes, such as the fern Ophioglossum reticulatum, have the highest number of chromosomes among the options. Ophioglossum reticulatum has 630 pairs of chromosomes (1260 chromosomes), making it the plant with the most chromosomes. This number is far greater than that of humans or other organisms, despite its smaller size.
8. Enzymes are produced by
Enzymes are produced by exocrine glands, which secrete substances such as enzymes through ducts to specific locations (like the digestive system). For example, the pancreas, an exocrine gland, produces digestive enzymes like amylase, lipase, and proteases.
9. Which one of the following organs breaks fat to produce cholesterol?
The liver plays a crucial role in breaking down fats and synthesizing cholesterol. It processes dietary fats and produces bile, which is essential for fat digestion and absorption. The liver also synthesizes cholesterol, which is used for various vital functions in the body.
10. The larva of the frog is called as
The larva of a frog is called a tadpole. It is an aquatic stage in the life cycle of frogs, where it has a tail and breathes through gills. Over time, the tadpole undergoes metamorphosis, developing legs and losing its tail, eventually transforming into an adult frog.
11. Ready source of energy available for athletes is
Carbohydrates are the body’s primary source of quick energy. For athletes, they are essential as they break down into glucose, which fuels muscles during physical activity. Although fats and proteins also provide energy, carbohydrates are the most readily available source for athletes.
12. What is the pH of blood?
The normal pH of human blood is slightly alkaline, typically around 7.35 to 7.45. This helps maintain proper bodily functions and enzyme activity. A pH of 7.4 is considered optimal for the body’s homeostasis.
13. The bones of the leg in the human body are
The bones of the leg in the human body are hollow, featuring a medullary cavity inside. This hollow structure makes the bones strong yet lightweight, allowing for efficient movement and support of the body. The design helps balance strength with reduced weight, enhancing mobility and overall function.
14. Malaria affects which part of the body?
Malaria primarily affects the spleen. The parasite Plasmodium, transmitted by mosquito bites, infects red blood cells and damages the spleen as it filters these infected cells. The spleen becomes enlarged as part of the body's immune response.
15. The stone formed in human kidney consist mostly of
The stone formed in human kidneys consists mostly of Calcium oxalate. These kidney stones are the most common type, formed when calcium combines with oxalate in the urine, leading to the formation of crystals that can grow into stones.
16. The salivary gland secrets saliva which contains the enzyme
The salivary glands secrete saliva, which contains the enzyme Ptyalin. Ptyalin, also known as salivary amylase, helps in the breakdown of starches into sugars during the process of digestion.
17. Which one of the following plants is used for green manuring in India?
Sunhemp is often used to improve soil fertility by adding organic matter and nitrogen to the soil. It is commonly grown in fields to enhance soil health before the main crop is planted.
18. The source of immediate energy for cellular activity is
ATP is the primary energy carrier in cells and is used for various cellular processes, such as muscle contraction, protein synthesis, and cell division.
19. The dried flower buds are used as a spice in
Cloves are aromatic flower buds from the plant Syzygium aromaticum and are commonly used in cooking and as a medicinal spice.
20. Who is affected by ‘Foot and Mouth Disease’?
Cattle are primarily affected by Foot and Mouth Disease (FMD). It is a contagious viral disease that affects cloven-hoofed animals, including cattle, pigs, sheep, and goats. Although it rarely affects humans, it can cause severe economic losses in livestock farming.
21. Which one of the following is not an essential micronutrient for plants?
Plants require micronutrients in small amounts for proper growth and development. Essential micronutrients include Boron (B), Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Molybdenum (Mo), and Chlorine (Cl). While sodium (Na) can be beneficial for some plants, especially C4 plants, it is not considered essential for all plants.
22. Anatomy is the branch of science which deals to
Anatomy is the branch of science that studies the structure of animals and plants, including their organs, tissues, and overall form. It is divided into gross anatomy (study of large body structures) and microscopic anatomy (study of cells and tissues).
23. Antigens are present
Antigens are molecules present on the surface of cells, typically proteins or polysaccharides, that trigger an immune response. They help the immune system recognize and differentiate between self and foreign substances, such as bacteria, viruses, or infected cells.
24. The glands of the body which pour their secretions directly into the blood stream are known as
Endocrine glands secrete hormones directly into the bloodstream without using ducts. Examples include the pituitary gland, thyroid gland, adrenal glands, and pancreas (for insulin production). These hormones regulate various body functions such as metabolism, growth, and reproduction.
25. Which one among the following parts of castor seed yields oil?
In castor seeds, oil is primarily stored in the endosperm, which provides nutrition for the developing embryo. The castor seed endosperm contains castor oil, which is rich in ricinoleic acid and widely used in industries for medicinal, cosmetic, and lubricant purposes.