Deck 15: Molecular Evolution

Question 1

Mutations tend to accumulate in amino acids, proteins and in DNA at a relatively constant rate and this property has been used to estimate the length of time organisms have been diverged from each other. While imprecise in many ways, this methodology is known as:

A) DNA sequencing
B) RNA sequencing
C) Amino acid substitution
D) Molecular cloning
E) Molecular clock

Answer 1

E
Molecular clock

Question 2

Gene duplication has been an important process in the formation of many new genes over the course of time. One prominent example of this is found in the protein:

A) Albumin
B) Hemoglobin
C) Cytochrome b
D) Fibrinogen
E) Collagen

Answer 2

B
Hemoglobin

Question 3

Much of our genome is for non-coding DNA that is not directly involved with the making of genes. This DNA whose function is unknown is sometimes referred to as "junk" DNA. Though not "garbage", this non-coding DNA is a significant part of our genome. Approximately what percentage of the human genome is so called "junk DNA"?

A) 10%
B) 25%
C) 33%
D) 50%
E) 90%

Answer 3

E
90%

Question 4

Hemoglobin exists in two forms, and alpha and a beta cluster, each on different chromosomes (11 and 16). Associated with each cluster are regions that has lost their ability to make hemoglobin due to a (frameshift) mutation. Such defunct relatives of known genes that have lost their coding ability and thus no longer expressed are known as:

A) Hemigenes.
B) Homeotic genes
C) Pseudogenes
D) Delta genes
E) Psi genes

Question 5

Mutations that are responsible for causing dramatic developmental transformations of body structure have been found in organisms as diverse of fruit flies to mice to humans. The "master" genes that are responsible for determining which parts of the body form what body parts are called:

A) Pseudogenes
B) Homeotic genes
C) Epistatic genes
D) Pleiotropic genes
E) Pseudoautosomal genes

Question 6

Vertebrates have a special kind of master gene that controls the pattern formation of early embryos known as Hox genes. One of the important characteristics of Hox gens is:

A) Their unique DNA sequence
B) Their unique amino acid sequence.
C) Their tendency toward homology across major taxonomic classes (e.g., from mouse to frog to fruit fly).
D) All of the above.
E) None of the above.

Question 7

One kind of "master gene" is called the Pax genes and they are key regulators of the development of various parts of the body, most notably the

A) Head
B) Ears
C) Eyes
D) Heart
E) Kidneys

Question 8

To demonstrate the effects of signaling molecules, scientists have applied chemicals (retinoic acid) to the amputated tail of a frog tadpole. In place of the tail, the frog developed a(n)

A) eye
B) head
C) leg
D) nose
E) heart

Question 9

Mitochondria is maternally inherited and is thus past along the female lineage. Based on mitochondrial DNA analysis, all humans females alive today have a common ancestor or group of individual (sometimes referred to as "mitochondrial Eve") from which all modern females are descended that lived roughly

A) 1 million years ago
B) 500,000 years ago
C) 200,000 years ago
D) 50,000 years ago
E) 20,000 years ago.

Question 10

The common ancestor of all human males has been traced using the Y-chromosome and the common ancestor, called Y-chromosome Adam, is seen as a group of men from whom all modern men are descended. Approximately how long ago does Y-chromosome data suggest that all human males had a common ancestor?

A) 1 million years ago
B) 600,000 years ago
C) 300,000 years ago
D) 150,000 years ago
E) 15,000 years ago.

Question 11

Where in the world did mitochondrial Eve and Y-chromosome Adam evolve and then migrate from to populate the Earth?

A) Europe
B) Asia
C) Africa
D) The Middle East
E) North America

Question 12

Eyes may have evolved as many as 60 times during the course of evolution or may have diverged from a common genetic pattern. Assuming eyes developed independently dozens of time in different lineages, this would be an example of:

A) Analogy
B) Homology
C) Convergent evolution
D) Divergent evolution
E) Adaptive radiation

Question 13

Under the notion of neutral mutations, what happens to neutrally selected for genes?

A) They randomly drift and are either lost or become fixed in the population.
B) They eventually become beneficial or deleterious gene and are then selected upon.
C) They hybridize to form new gene combinations.
D) They mutate and are then lost to the gene pool.
E) They undergo gene duplication and later recombination.

Question 14

Based on molecular data, the common ancestor of the chimp and the human diverged approximately:

A) 15 million years ago
B) 10 million years ago
C) 5 million years ago
D) 2 million years ago
E) 1 million years ago

Question 15

A 100 amino acid enzyme that is essential for respiration and is evolutionarily ancient and highly conserved has been used to compare organism and thereby estimate their degree of relatedness. What is this enzyme?

A) Hemoglobin
B) Myoglobin
C) Cytochrome b
D) Ribosomal nuclease
E) Reverse transcriptase