Biology Discoveries — Set 4

Correct Answer: D. Stanley Prusiner

• **Stanley Prusiner** = He identified prions as a new class of infectious agents without DNA or RNA, causing diseases like Mad Cow disease. • **1997** — Prusiner was awarded the Nobel Prize for his controversial discovery of prions. • 💡 Wrong-option analysis: Luc Montagnier: known for co-discovering HIV; Robert Gallo: also contributed to HIV research; Baruch Blumberg: discovered the Hepatitis B virus.

Correct Answer: A. William Bayliss

• **William Bayliss** = He, along with Ernest Starling, discovered the first hormone, secretin, pioneering the understanding of chemical messengers. • **1902** — This was the year Bayliss and Starling discovered secretin, proving chemical messengers travel via blood to trigger organ responses. • 💡 Wrong-option analysis: Ernest Starling: he co-discovered secretin and coined the term 'hormone', but the specific answer chosen is Bayliss; All of the mentioned: not the designated single answer; Frederick Banting: co-discovered insulin, a later hormone discovery.

Correct Answer: A. Alick Isaacs

• **Alick Isaacs** = He, along with Jean Lindenmann, discovered interferons, which are proteins produced by cells to fight viral infections. • **1957** — Isaacs and Lindenmann discovered interferons while studying how one virus infection prevents another. • 💡 Wrong-option analysis: Jean Lindenmann: he co-discovered interferons with Alick Isaacs; All of the mentioned: not the designated single answer; Edward Jenner: known for developing the smallpox vaccine.

Correct Answer: B. Richard Altmann

• **Richard Altmann** = He identified mitochondria in **1890**, calling them 'bioblasts' and believing them to be independent living units within cells. • **1890** — Altmann identified mitochondria in this year; Carl Benda later renamed them 'mitochondria' in 1898. • 💡 Wrong-option analysis: Robert Brown: known for discovering the cell nucleus and Brownian motion; Carl Benda: later renamed 'bioblasts' to 'mitochondria'; Albert von Kölliker: first observed them in muscle cells in the mid-19th century but didn't identify them as 'bioblasts'.

Correct Answer: A. Luc Montagnier

• **Luc Montagnier** = He, with Françoise Barré-Sinoussi, isolated the HIV virus at the Pasteur Institute, identifying it as the cause of AIDS. • **1983** — Montagnier and Barré-Sinoussi isolated the HIV virus in this year; they later shared the Nobel Prize in **2008**. • 💡 Wrong-option analysis: Robert Gallo: his team also made significant contributions to identifying HIV; Françoise Barré-Sinoussi: she co-discovered HIV with Luc Montagnier; Other than listed: Montagnier is specifically listed.

Correct Answer: C. Elie Metchnikoff

• **Elie Metchnikoff** = He discovered phagocytosis by observing white blood cells engulfing harmful particles, identifying it as a key defense against infection. • **1908** — Metchnikoff shared the Nobel Prize in this year with Paul Ehrlich for their work on immunity. • 💡 Wrong-option analysis: Louis Pasteur: known for pasteurization and vaccine development; Paul Ehrlich: shared the Nobel Prize with Metchnikoff for immunology but Metchnikoff discovered phagocytosis; Robert Koch: known for his postulates on infectious diseases and isolating tuberculosis bacteria.

Correct Answer: A. Max von Laue

• **Max von Laue** = He discovered X-ray diffraction in crystals, a fundamental principle that underpins X-ray crystallography for revealing molecular structures. • **1914** — Von Laue was awarded the Nobel Prize in Physics in this year for his discovery of X-ray diffraction by crystals. • 💡 Wrong-option analysis: William and Lawrence Bragg: developed Bragg's Law, crucial for interpreting X-ray diffraction patterns; Rosalind Franklin: played a critical role in X-ray diffraction of DNA; Other than listed: Max von Laue is specifically listed.

Correct Answer: A. Howard Temin

• **Howard Temin** = He independently discovered the reverse transcriptase enzyme, which copies RNA back into DNA, challenging the Central Dogma of molecular biology. • **1975** — Temin and Baltimore were awarded the Nobel Prize in this year for their independent discoveries of reverse transcriptase. • 💡 Wrong-option analysis: David Baltimore: he independently co-discovered reverse transcriptase; All of the mentioned: not the designated single answer; James Watson: co-discovered the structure of DNA, not reverse transcriptase.

Correct Answer: A. Otto Loewi

• **Otto Loewi** = He demonstrated chemical transmission of nerve impulses through his famous frog heart experiment, discovering the first neurotransmitter. • **1936** — Loewi and Henry Dale shared the Nobel Prize in this year for their discoveries concerning chemical transmission of nerve impulses. • 💡 Wrong-option analysis: Henry Dale: he co-proved chemical transmission of nerve impulses with Loewi; All of the mentioned: not the designated single answer; Camillo Golgi: developed a staining technique for neurons and contributed to neuron doctrine.

Correct Answer: B. Marcello Malpighi

• **Marcello Malpighi** = He discovered blood capillaries by observing them in a frog's lung, providing the missing link in Harvey's theory of blood circulation. • **1661** — Malpighi observed capillaries using a microscope in a frog's lung in this year. • 💡 Wrong-option analysis: William Harvey: proposed the theory of blood circulation but didn't observe capillaries; Robert Hooke: coined the term 'cell' and made observations with a microscope; Antonie van Leeuwenhoek: known for improving the microscope and observing microorganisms.