Biology First Sem

What is the biosphere?

The part of Earth where all living organisms reside and interact.

What are the main differences between Earth's systems for matter and energy?

Earth is a closed system for matter and an open system for energy.

What are the four main spheres of the Earth system?

Geosphere, Hydrosphere, Biosphere, Atmosphere.

Define an ecosystem.

Ecosystems consist of biotic (living) and abiotic (non-living) components interacting and cycling energy and matter.

What is a population in ecological terms?

A group of individuals from the same species in a specific area.

What is the main role of homeostasis in living organisms?

Maintaining stable internal conditions despite external changes, essential for survival.

What are the three types of symbiotic relationships?

Mutualism, Parasitism, Commensalism.

What is biodiversity?

The variety of species within a specific area.

What is the equation for photosynthesis?

6CO2 + 6H2O → C6H12O6 + 6O2.

How does ATP release energy?

ATP releases energy when a bond is broken, converting it to ADP.

Define a habitat.

The environment where an organism lives, encompassing biotic and abiotic factors.

What is a niche?

The specific role or function of an organism in its environment.

How do chlorophyll a and chlorophyll b function in photosynthesis?

They absorb light energy, with chlorophyll a absorbing primarily in the red spectrum and chlorophyll b assisting in capturing blue and orange wavelengths.

What are the main types of carbon-based compounds in living organisms?

Lipids, proteins, nucleic acids, and carbohydrates.

What is the difference between reactants and products in a chemical reaction?

Reactants are the substances that undergo change, while products are the new substances formed.

What is the significance of the electron transport chain in photosynthesis?

It converts light energy into chemical energy (ATP, NADPH).

Describe photolysis in the light-dependent reactions.

It is the process of splitting water molecules into oxygen, protons, and electrons, providing necessary electrons for chlorophyll.

What is meant by species richness?

The count of different species within a unit area.

What is a community in ecological terms?

Multiple populations of different species coexisting in an area.

What are the inputs and outputs of photosynthesis?

Inputs: Carbon dioxide, water, light; Outputs: Glucose, oxygen.