Biology in Class 10 : Practice MCQ Questions & Answers with Explanations

Ethylene is a gaseous plant hormone that regulates several processes, including fruit ripening, by breaking down cell walls and converting starches to sugars.

The epiglottis is a flap-like structure that covers the windpipe (trachea) when swallowing, ensuring that food enters the esophagus instead of the respiratory tract.

The pulmonary vein is the only vein in the human body that carries oxygen-rich blood, transporting it from the lungs to the left atrium of the heart.

Alveoli are microscopic air sacs in the lungs where oxygen diffuses into the blood and carbon dioxide is expelled, making them the primary site for gas exchange.

Decomposers, such as fungi and bacteria, play an essential role in breaking down dead and decaying organic matter, recycling nutrients back into the ecosystem.

A dominant trait is visible when a dominant allele is present, even if the organism is heterozygous (has one dominant and one recessive allele).

Binary fission is a simple asexual reproduction method where a single organism splits into two identical daughter organisms, commonly seen in bacteria.

Life processes refer to basic activities required for the survival of living organisms, such as nutrition, respiration, transport, excretion, and reproduction.

Yeast reproduces asexually through budding, where a new cell develops as an outgrowth of a parent cell and eventually detaches to form an independent organism.

Stomata are tiny pores on leaf surfaces that facilitate the exchange of gases, allowing plants to absorb carbon dioxide and release oxygen and water vapor during photosynthesis and respiration.

Cellular respiration is a metabolic process where glucose is broken down in the presence of oxygen to produce ATP, the energy required for cellular activities.

Villi are finger-like projections in the small intestine that increase the surface area for maximum absorption of nutrients from digested food into the bloodstream.

Producers, like green plants, synthesize their own food using sunlight through photosynthesis, forming the base of the food chain.

A food chain represents the flow of energy in an ecosystem, where one organism eats another, transferring energy from producers to consumers and finally to decomposers.

A gene is the smallest unit of heredity, found on chromosomes. It carries the instructions for specific traits and is made up of DNA.

Insulin, secreted by the pancreas, helps regulate blood sugar levels by enabling cells to absorb glucose for energy or storage, thereby reducing glucose concentration in the blood.

The combination of sex chromosomes determines the baby's gender. Females have XX chromosomes, while males have XY chromosomes, with the father's contribution deciding the outcome.

Homologous organs, such as the flippers of whales and the arms of humans, share a similar structural design due to common ancestry but serve different functions.

Vitamin K is crucial for synthesizing proteins involved in blood clotting, helping to prevent excessive bleeding during injuries by promoting clot formation.

The cerebrum is the largest part of the human brain, responsible for voluntary actions, sensory interpretation, memory, speech, and higher-order thinking such as decision-making.