Conventions of Punctuation

Type the punctuation mark that belongs in the blank to join the two independent clauses.

Botanists were shocked in 1994 when they discovered a small grove of Wollemi pines in a remote Australian canyon. The prehistoric trees, which were previously thought to have been extinct for millions of years, survived in deep sandstone gorges. Conservationists immediately began a propagation program to safeguard the species.

Which of the following is the best punctuation for the underlined portion of the sentence?

The following passage is an excerpt from a history of Mayan archaeology.

For decades, Mayan scholars believed that the hieroglyphs carved into stone stelae recorded only mythical stories and astronomical tables. In 1960, Tatiana Proskouriakoff published a breakthrough study of the glyphs at Piedras Negras. She demonstrated that the monument inscriptions, which were carved at regular intervals of five hotuns, actually detailed the births, accessions, and victories of historical rulers.

Which choice best punctuates the underlined portion of the sentence?

The following passage is an excerpt from a biography of a historic figure.

When the chief engineer of the Brooklyn Bridge fell ill in 1872, his wife Emily Warren Roebling stepped in to manage the daily operations of the monumental project. The engineers who drafted the daily blueprints, which were critical to the project, met with Emily Roebling every morning to receive instructions. Ultimately, her dedication ensured the successful completion of what was then the longest suspension bridge in the world.

Which of the following is the most effective punctuation for the underlined portion of the passage?

The following passage is an excerpt from an essay on the history of science.

In the mid-twentieth century, the scientific community remained skeptical of plate tectonics. Marie Tharp, a pioneering cartographer, created the ocean map that proved the theory of continental drift. Her meticulous work revealed the dramatic topography of the ocean floor, transforming geology forever.

Which choice is the correct punctuation for the underlined portion of the sentence?

To successfully harvest natural vanilla, farmers must execute a tedious task, they must hand-pollinate each orchid blossom during a narrow morning window.

Which choice most effectively punctuates the underlined portion of the sentence?

To determine the age of the ancient timber, the dendrochronologists extracted several thin cylindrical, core samples, and they examined the growth rings under a high-powered microscope.

Which choice best punctuates the underlined portion of the sentence?

Many plant species rely on mutualistic relationships with fungi to absorb nutrients from the soil. The ghost orchid, which lacks leaves and chlorophyll, depends entirely on mycorrhizal fungi for survival. Without this symbiotic partner, the orchid seeds would fail to germinate.

Which choice best punctuates the underlined portion of the sentence?

To prepare for the upcoming gallery exhibition, the curator carefully inspected the delicate, ancient, oil paintings, organized the display cases, and finalized the guest list.

Which of the following options represents the correct punctuation for the underlined portion of the sentence?

In the mid-twentieth century, computer scientist Grace Hopper developed a compiler that translated English-like instructions into machine code, this innovation paved the way for modern programming languages.

Which of the following is the most appropriate punctuation for the underlined portion of the sentence?

After the library acquired the rare medieval manuscript, several local scholars' primary concern was it's fragile binding, which required immediate conservation.

Which of the following choices best completes the underlined portion of the sentence?

To bake authentic sourdough bread, a chef needs only two basic ingredients: flour and water.

Which choice best punctuates the underlined portion of the sentence?

In certain dense forests, the uppermost branches of neighboring trees avoid touching one another, instead, they form a network of distinct, channel-like gaps known as 'crown shyness.'

Which choice most effectively punctuates the underlined portion of the sentence?

In 1928, Scottish biologist Alexander Fleming made an accidental discovery in his laboratory. A strange mold, which grew in a neglected petri dish, was killing the surrounding bacteria. This chance observation led to the development of penicillin, the world's first modern antibiotic.

Which choice best punctuates the underlined portion of the sentence?

Which punctuation mark is grammatically appropriate to join the two closely related independent clauses in the sentence below?

During the international pastry competition, the two bakers worked under intense pressure. The bakers' chief concern was it's structural stability, as the warm kitchen threatened to melt the delicate sugar sculpture.

Which choice best corrects the underlined portion of the sentence?

The following passage contains an underlined portion.

In the mid-nineteenth century, the visionary mathematician Ada Lovelace collaborated with inventor Charles Babbage on his mechanical calculator, the Analytical Engine. Lovelace recognized that the machine had applications beyond mere calculation, translating an article on the engine and appending her own extensive commentary. Her detailed notes, which researchers now consider the first computer program described how the machine could compute a sequence of complex numbers.

Which of the following choices represents the correct punctuation for the underlined portion?

Read the passage below and answer the question that follows.

Located off the coast of Australia, the Great Barrier Reef is the largest coral reef system on Earth. The Great Barrier Reef, which stretches over 1,400 miles is home to thousands of unique marine species. Protecting this fragile ecosystem is a primary concern for modern marine biologists.

Which of the following choices represents the correct punctuation for the underlined portion of the sentence?

Although the engineering department hired several automotive designers to build the new hybrid vehicle, the designers' main concern was it's heavy battery pack.

Which of the following options represents the correct punctuation and word usage for the underlined portion?

Choose the alternative that best punctuates the underlined portion of the sentence.

Although the chemists synthesized a dense, dark, metallic compound that was stable at room temperature; they could not determine its catalytic properties.