Science

Biology semester 1

1. Explain the importance of classifying living and non-living things using the seven life processes (MRS GREN).

1. Classifying living and non-living things using the seven life processes (MRS GREN) helps biologists organize and understand the diversity of life. MRS GREN stands for Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition.

1. Identify information on viruses and classify a virus as living or non-living.

1. Viruses are unique entities that exhibit some characteristics of living organisms, such as the ability to reproduce, but only within a host cell. They lack cellular structure and metabolism, so they are often classified as non-living.

1. Discuss the reasons for classifying organisms, such as identification and communication.

1. Classification helps in identifying organisms by grouping them based on shared characteristics. It also facilitates communication among scientists from different cultures or regions, ensuring they are observing the same organism.

1. Use diagrammatic and descriptive dichotomous keys to identify specimens.

1. Dichotomous keys are tools used to identify organisms based on a series of choices that lead to the correct name of the organism. Diagrammatic keys use pictures, while descriptive keys use tables.

1. Classify organisms using hierarchical systems such as kingdom, phylum, class, order, family, genus, and species.

1. Organisms are classified using hierarchical systems that include kingdom, phylum, class, order, family, genus, and species. This system helps in understanding the relationships and evolutionary history of organisms.

1. Describe the major characteristics of the five kingdoms of classification: Plantae, Animalia, Fungi, Protista, and Eubacteria.

1. The five kingdoms of classification are:

   • Plantae: Multicellular, photosynthetic organisms (plants).

   • Animalia: Multicellular, heterotrophic organisms (animals).

   • Fungi: Organisms that absorb nutrients from organic matter (fungi).

   • Protista: Single-celled or simple multicellular organisms (protists).

   • Eubacteria: Single-celled prokaryotic organisms (bacteria).

1. : Identify the major invertebrate phyla and provide examples of each.

1. The major invertebrate phyla include:

   • Poriferans (sponges): Simple, porous organisms.

   • Cnidarians (jellyfish): Organisms with stinging cells.

   • Echinoderms (starfish): Marine organisms with radial symmetry.

   • Annelids (segmented worms): Worms with segmented bodies.

   • Molluscs (snails): Soft-bodied organisms, often with shells.

   • Arthropods (insects): Organisms with exoskeletons and jointed limbs.

1.     Explain how energy flows through an ecosystem using a food chain as an example.

1. Energy flows through an ecosystem in a food chain starting from the sun, which provides energy to producers (plants). Herbivores (primary consumers) eat the plants, and carnivores (secondary consumers) eat the herbivores. Decomposers break down dead organisms, returning nutrients to the soil.

1. : Describe the role of decomposers in nutrient cycling within an ecosystem.

1. : Decomposers, such as bacteria and fungi, play a crucial role in nutrient cycling by breaking down dead organic matter and releasing nutrients back into the soil, which can be used by plants.

1. Discuss how the introduction of a non-native species like the cane toad can affect local biodiversity.

1. : The introduction of a non-native species like the cane toad can disrupt local biodiversity by preying on native species, competing for resources, and introducing diseases. This can lead to a decline in native populations and alter the ecosystem’s balance.

1. Define what a habitat is and list factors that contribute to its suitability for different organisms.

1. A habitat is the natural environment where an organism lives. Factors contributing to its suitability include availability of food, water, shelter, and appropriate climate conditions.

1. Compare and contrast the concepts of food chains and food webs.

1. Food chains show a linear sequence of who eats whom in an ecosystem, while food webs are more complex and show multiple feeding relationships among organisms in an ecosystem.

: Evaluate the impact of human activities on water management within an ecosystem.

Human activities, such as pollution, deforestation, and urbanization, can negatively impact water management within an ecosystem by altering water quality, availability, and distribution, leading to habitat loss and reduced biodiversity.

1. Investigate how changes in one part of a food web can affect other parts.

1. Changes in one part of a food web, such as the removal of a top predator, can have cascading effects on other parts of the web. For example, the removal of a predator can lead to an increase in herbivore populations, which can overgraze vegetation and disrupt the ecosystem.