JSS2 Basic Science First Term Exam

Reproduction is the biological process through which living organisms create offspring, ensuring the continuation of their species. This process can occur through various methods, including sexual and asexual reproduction, allowing for genetic diversity or the production of genetically identical individuals. Unlike digestion, which involves breaking down food for energy, or menstruation, a biological cycle in some female organisms, reproduction specifically pertains to the generation of new life. Thus, it is the fundamental mechanism by which organisms perpetuate their kind.

Bread and yam are primarily composed of carbohydrates, which are essential macronutrients that provide energy to the body. Carbohydrates are found in various forms, including sugars, starches, and fibers. Both bread and yam are rich in starch, a complex carbohydrate that the body breaks down into glucose for energy. This makes them important sources of fuel, especially in diets that require high energy levels for physical activity. Hence, they are classified under carbohydrates.

An aquatic habitat refers to environments such as oceans, rivers, lakes, and ponds where water is the primary medium for living organisms. This habitat supports a diverse range of life forms, including fish, plants, and microorganisms, which have adapted to thrive in water. In contrast, arboreal habitats are tree-based, body habitats refer to the physical structure of organisms, and terrestrial habitats are land-based environments. Thus, the term "aquatic habitat" specifically denotes water-based ecosystems.

The statement that "the earth produces its own light by day" is false because the Earth does not generate its own light. Instead, it reflects sunlight, which is why we experience daylight. The sun is the primary source of light for the Earth, while the moon reflects sunlight, making it visible at night. In contrast, the sun is a star, and it is responsible for illuminating our planet during the day.

Condensation is the process where gas transitions into a liquid state as it cools down. When gaseous molecules lose energy, they come closer together, forming liquid droplets. This phenomenon is commonly observed when water vapor in the air cools and forms dew or when steam cools to become water. Unlike boiling, which involves the conversion of liquid to gas, condensation specifically refers to the reverse process, making it essential in understanding the water cycle and various industrial applications.

HIV stands for Human Immune Deficiency Virus, which is a virus that attacks the body's immune system, specifically the CD4 cells (T cells). If untreated, it can lead to AIDS (Acquired Immunodeficiency Syndrome), a condition where the immune system becomes severely compromised. Understanding the full name helps clarify the virus's impact on human health, emphasizing its role in diminishing the immune response, making individuals more susceptible to infections and diseases.

A habitat is defined as the natural environment in which a particular species or community of organisms lives and thrives. It provides essential resources such as food, water, shelter, and space, which are crucial for survival and reproduction. Each habitat supports a specific set of organisms adapted to its conditions, making it a fundamental concept in ecology and biology. Understanding habitats helps in the conservation of biodiversity and the management of ecosystems.

Development refers to the series of changes and processes that living organisms undergo as they grow and mature. This encompasses physical, cognitive, and emotional transformations that occur from infancy through adulthood. Unlike mere growth, which focuses primarily on size increase, development includes the overall progression of an organism’s capabilities and functions, making it a broader concept that captures the essence of maturation in living things.