How well do you understand living things and their vital processes? Whether you are preparing for JAMB, WAEC, NECO and Post-UTME, these Biology past questions and answers cover such subjects as the chemistry of life, botany, evolution, genetics, ecology etc to help you know what to expect, improve your speed and confidence and be really prepared for the actual aptitude test.
Which of the following mechanisms is responsible for providing support in plants?
Muscles and bones
Exoskeleton
Endocrine system
Cell walls and turgor pressure
Correct answer is D
The mechanism responsible for providing support in plants is the combination of cell walls and turgor pressure. In plants, the cell walls, composed of cellulose, provide structural support to the cells and tissues. They give rigidity and strength to plant cells, enabling them to maintain their shape and resist external forces. Additionally, turgor pressure, which is the pressure exerted by the cell contents against the cell walls, helps maintain the overall rigidity and upright form of plants.
Which of the following is a primary source of pollution in aquatic ecosystems?
Soil erosion
Industrial discharge
Air pollution
Deforestation
Correct answer is B
Industrial discharge refers to the release of pollutants, such as chemicals, heavy metals, and wastewater, from industrial activities into water bodies. This is a primary source of pollution in aquatic ecosystems. Industries generate various pollutants that are often released into nearby water bodies, leading to water pollution and adverse effects on aquatic organisms and ecosystems.
Which of the following is a plant hormone responsible for promoting cell elongation and growth?
Abscisic acid
Gibberellins
Ethylene
Cytokinins
Correct answer is B
Gibberellins are plant hormones that play a significant role in promoting cell elongation and growth.
Which of the following statements is true regarding sex-linked traits?
Sex-linked traits are located on the sex chromosomes
Sex-linked traits are inherited only from the mother
Sex-linked traits are more commonly observed in females
Sex-linked traits are not influenced by hormonal factors
Correct answer is A
Sex-linked traits are traits that are determined by genes located on the sex chromosomes (X and Y chromosomes in humans).
Competition leads to the selection of individuals with favorable traits for survival and reproduction
Competition ensures equal distribution of resources among individuals in a population
Competition leads to the development of new traits and adaptations in a population
Competition reduces the need for adaptations as individuals coexist peacefully
Correct answer is A
When individuals within a population compete for limited resources such as food, water, or mates, those individuals with favorable traits that enhance their ability to acquire resources are more likely to survive and reproduce.