Science Reviewer: Biodiversity and Biogeochemical Cycles

Practice questions covering biodiversity, the six kingdoms, domains of life, and biogeochemical cycles including the Carbon-Oxygen, Water, Phosphorus, and Nitrogen cycles.

What is biodiversity?

The variety of life in all its forms, levels, and combinations.

How are organisms classified based on cell count?

Multicellular organisms have $2$ or more cells, while unicellular organisms consist of a single cell.

What is the difference between heterotrophs and autotrophs?

Heterotrophs are organisms that eat other organisms for food, whereas autotrophs create their own food.

Contrast eukaryotic and prokaryotic cells.

Eukaryotic cells have a true nucleus and membrane-bound organelles and are larger and more complex; prokaryotic cells have no true nucleus or membrane-bound organelles and are smaller and simpler.

What are the roles of DNA, RNA, and proteins?

DNA (Deoxyribonucleic acid) stores information about the organism; RNA (Ribonucleic acid) helps cells use genetic information; Proteins are responsible for making a copy of DNA traits.

What are the three levels of biodiversity?

1. Diversity of Genes (genetic differences), 2. Diversity of Species (different kinds of organisms), and 3. Diversity of Ecosystems (different places where organisms live and their interactions).

What are the unique characteristics of Archaebacteria?

They are unicellular, prokaryotic organisms that can survive conditions most organisms cannot tolerate.

What defines Kingdom Eubacteria?

They are unicellular, prokaryotic organisms found almost everywhere.

What are the characteristics of Kingdom Animalia?

Multicellular, eukaryotic organisms that are heterotrophs and capable of movement.

What characterizes Kingdom Plantae?

Multicellular, eukaryotic autotrophs that make food through photosynthesis, contain chlorophyll, and are usually rooted in one place.

What is a saprophyte in the context of Kingdom Fungi?

An organism, often multicellular but sometimes unicellular and eukaryotic, that absorbs nutrients from dead or decaying matter.

How is Kingdom Protista described?

Mostly unicellular eukaryotic organisms that may be plant-like, animal-like, or fungus-like.

Who developed the $7$ levels of classification?

Carolus Linnaeus, a Swedish naturalist during the $18^{th}$ Century.

What are the three types of Domain?

1. Bacteria (common microorganisms like Eubacteria), 2. Archaea (extreme environment organisms like Archaebacteria), and 3. Eukarya (plants, animals, fungi, and protists).

What defines a mammal?

A warm-blooded vertebrate in the class Mammalia that produces milk for their young, has hair or fur, and possesses a backbone.

What are the key stages of the Carbon and Oxygen Cycle?

Photosynthesis (carbon fixation), animals eating plants, respiration (releasing $CO_2$), decomposition, and combustion of fossil fuels.

How does the water cycle function?

It involves evaporation, condensation into clouds, precipitation, transpiration from plants, and respiration or sweating from animals.

What is weathering in the Phosphorus Cycle?

The process where rainfall and natural erosion break down phosphate rocks to release inorganic phosphate ions into soil and water.

What is mineralization in the Phosphorus Cycle?

When decomposers (bacteria and fungi) break down organic matter from dead plants or animals and convert organic phosphorus back into inorganic phosphates.

What happens during Nitrogen Fixation?

Special bacteria or lightning change unusable nitrogen gas from the air into ammonia or nitrates that plants can absorb.

What is assimilation in the Nitrogen Cycle?

The process where plants take in usable nitrogen compounds through their roots to build proteins and DNA.

What is nitrification?

Soil bacteria change ammonia into nitrites and then into nitrates for plant use.

What is the role of denitrification?

Bacteria in soil or water convert excess nitrates back into nitrogen gas, releasing it into the atmosphere.