QCM : Fundamentals of Life and Evolution — 9 questions

Explication

Charles Darwin is credited with proposing the theory of evolution by natural selection, which explains how species adapt through genetic changes over generations, making him the key figure associated with the concept of adaptation in the context of the characteristics of life.

Explication

The immense size range from nanometres to meters requires scientists to use specific measurement units like micrometres and nanometres, enabling accurate study and comparison of biological structures at different scales.

Explication

Variation refers to the differences that exist among individuals within a population, providing the raw material for natural selection to act upon. This is explicitly stated in the source, making it the correct answer. The other options describe related but distinct concepts: inheritance, selection, and evolution, respectively.

Explication

The endosymbiosis events that led to mitochondria and chloroplasts are believed to have occurred approximately 1.5 billion years ago during early eukaryotic evolution, making them some of the earliest significant events in the development of complex life.

Explication

Shared characters are traits indicating common ancestry and are fundamental in constructing phylogenetic trees to reveal relationships. Outgroups are used to root trees, providing a reference point that helps determine the direction of evolutionary change. Hence, their roles are different but complementary in phylogenetic analysis.

Explication

The RNA world hypothesis emphasizes that RNA molecules played a dual role in early life: storing genetic information and catalyzing chemical reactions. This functional versatility made RNA crucial in the development of the first life forms, acting both as genetic material and as a catalyst.

Explication

Fossil evidence such as microfossils and stromatolites allows scientists to date when early life forms existed, helping to establish the timeline of life's origins on Earth. Dating fossils is the primary application for understanding the history of early life, whereas analyzing chemical composition can help with dating but is not the main application. Comparing structures can inform about relationships but doesn't directly establish the timeline. Recycling fossils is not a scientific practice for understanding history.

Explication

The micrometre is a unit used to measure the size of cells and organelles, with eukaryotic cells typically ranging from 10 to 100 micrometres, making option 1 the correct answer. The other options refer to scales either too small or unrelated to the typical biological structures measured in micrometres.

Explication

The source states that a distinctive feature of some Archaea is their ability to grow at temperatures exceeding 100℃, setting them apart from Bacteria and Eukarya. The other options refer to features characteristic of Bacteria (peptidoglycan in cell walls) and Eukarya (membrane-enclosed organelles, nuclear envelope), but are not unique to Archaea.