Nucleic Acids and Origin of Life Worksheet

Front

What is the structural organization of nucleic acids?

Back

Nucleic acids, such as DNA and RNA, have a sugar-phosphate backbone and are composed of nucleotides. DNA forms an antiparallel double helix stabilized by hydrogen bonds between complementary bases.

Front

What is the difference between chemical evolution and the origin-from-space hypothesis?

Back

Chemical evolution suggests that life arose from spontaneous formation of complex molecules on early Earth, while the origin-from-space hypothesis posits that organic molecules or life were delivered to Earth via meteorites or comets.

Front

What does it mean if two species share a derived trait in a cladogram?

Back

It indicates that the two species inherited the trait from a common ancestor.

Front

What is a synapomorphy in a cladogram?

Back

A synapomorphy is a shared derived trait that indicates a common ancestor among the groups that possess it.

Front

What does the root of a phylogenetic tree represent?

Back

The root represents the most recent common ancestor of all organisms in the tree.

Front

Define nucleotides.

Back

Nucleotides are the building blocks of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.

Front

What is the role of hydrogen bonds in DNA structure?

Back

Hydrogen bonds between complementary bases (adenine-thymine and guanine-cytosine) stabilize the double helix structure of DNA.

Front

Explain the concept of convergent evolution.

Back

Convergent evolution occurs when different species independently evolve similar traits, often due to similar environmental pressures.

Front

What is a cladogram?

Back

A cladogram is a diagram that shows the evolutionary relationships among various species based on shared characteristics.

Front

What is the significance of a common ancestor in evolutionary biology?

Back

A common ancestor is an ancestral species from which two or more species have evolved, indicating a shared evolutionary history.