Question

part 1 — reading passages + short answer questions

1. characteristics of life: cells, viruses & bacteria

reading passage
all living things share certain characteristics: they are made of one or more cells, use materials, grow and develop, respond to their environment, reproduce (mitosis, homeostasis, bacteria are living organisms because they are made of cells, can reproduce on their own, and use energy. viruses, however, are not living because they are not cells and cannot reproduce without a host cell.
short answer questions:

1. why are viruses not considered living organisms?
2. name two reasons bacteria are considered living.
3. what characteristic of life is connected to the ability to reproduce without a host?

1. matter & energy in ecosystems

reading passage
energy flows in one direction—from the sun to producers, then to consumers, and eventually is released as heat. matter (carbon, nitrogen, and water) are reused repeatedly.
short answer questions:

1. why is energy said to “flow” while matter “cycles”?
2. which organisms return nutrients to the soil?

1. population biology: carrying capacity & limiting factors

reading passage
every ecosystem has a carrying capacity—the largest number of individuals it can support. limiting factors include food availability, water, space, predators, and climate.
short answer questions:

1. what determines the carrying capacity of an environment?
2. how would a drought affect plant - eating animals?
3. give one biotic and one abiotic limiting factor.

1. photosynthesis & cellular respiration

reading passage
photosynthesis uses sunlight, co₂, and water to make glucose and oxygen. cellular respiration uses glucose and oxygen to create atp energy and releases co₂ and water. the two processes depend on each other.
short answer questions:

1. where does photosynthesis occur? where does cellular respiration occur?
2. explain how photosynthesis and respiration are connected.
3. what molecule provides usable energy to cells?

Explanation:

The problem is about biological concepts like characteristics of life, energy in ecosystems, and photosynthesis/respiration, which fall under Biology (a subfield of Natural Science). For the first short - answer question "Why are viruses not considered living organisms?" in the "Characteristics of Life: Cells, Viruses & Bacteria" section: Viruses lack key living characteristics. They are not made of cells, can't reproduce on their own (need a host cell to replicate), and don't perform metabolic processes independently. Living organisms are made of cells, can reproduce independently, and carry out metabolism. Since viruses fail these, they aren't living.

Answer:

Viruses are not considered living organisms because they are not made of cells, cannot reproduce on their own (they require a host cell to replicate), and do not carry out metabolic processes independently. Living organisms are composed of cells, can reproduce independently, and perform metabolic functions.