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Human Biology

Exam 1: Evolution, DNA & Viruses
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Which of the following statements would Darwin have disagreed with?
Descent with modification occurs through inheritance of acquired characteristics.
Broccoli, cabbages, and brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by
artificial selection
Which of the following best expresses the concept of natural selection?
differential reproductive success based on inherited characteristics
Which of the following assumptions or observations contradicts Darwin's idea of natural selection?
Whether an organism survives and reproduces is almost entirely a matter of random chance.
Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of
homology.
Darwin was the first person to draw an evolutionary tree, or cladogram , or phylogenetic diagram that represents
evidence-based hypotheses regarding our understanding of patterns of evolutionary descent.
The ultimate source of all new alleles is
mutation in parent cells (asexual organisms) or in cells that produce gametes (sexual organisms).
A biological species is defined as a group of organisms that
have the potential to interbreed in nature and produce fertile offspring.
Which provides the most general and correct description of the idea of a reproductive barrier?
any feature (of geography, behavior, or morphology) that keeps two species from producing offspring together
Which of the following types of reproductive barriers separates a pair of species that could interbreed except that one mates at dusk and the other at dawn?
temporal isolation
Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________, ________ reproductive barrier.
behavioral . . . prezygotic
The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes ________ speciation.
allopatric
Two bird species overlap in a hybrid zone. They are isolated by a slight difference in the male songs and by the females' tendency to select males with the "correct" song. Hybrid offspring tend to have reduced fertility compared to either of the parent species. What effect should natural selection have in this situation?
Natural selection will favor males with more distinctive calls and/or females that are more "choosy." As a result, the reproductive barrier between the two species will be reinforced.
Which of the following statements about the Galápagos finches is false?
Each island in the Galápagos chain has one and only one isolated, unique species of Darwin's finch.
The ________ suggests that speciation occurs in brief spurts.
punctuated equilibrium model
One of the key contributions of the punctuated equilibrium model is that it helps explain
why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans.
Compared to the earliest primates, anthropoids have
a larger brain relative to their body size.
Our closest relatives, the ________, exhibit several behaviors that closely resemble those of humans.
chimpanzees
The last common ancestor shared by humans and chimpanzees lived about
5 7 million years ago.
Hominid fossil footprints that are obviously bipedal date to about ________ years ago.
3.5 million
Which of the following is the first distinctively hominid trait to appear in the fossil record?
upright walking (bipedalism)
________ appears to have been the first hominid to use stone tools.
Homo habilis
According to the fossil record, the genus Homo first arose in
Africa.
The most recent evidence clarifying the relationship between modern humans and Neanderthals comes from analysis of
Neanderthal mitochondrial DNA.
Neanderthals are best described as
a hominid that colonized Europe independently of Homo sapiens and was out-competed by them
Fossil and genetic evidence strongly support the idea that modern humans
all derive from a single African lineage that spread from there into other parts of the world starting about 60,000 years ago.
Compared to other hominids, modern Homo sapiens display a particular ability for
symbolic thought
All humans alive today have inherited their mitochondrial DNA from some individual female common ancestor. Studies indicate this woman probably lived about ________ years ago, when fossil evidence indicates Homo sapiens was restricted to ________.
180,000 . . . Africa
Which of the following human practices has most seriously threatened the destruction of present species which will highly influence further evolution on this planet
Habitat destruction. Clearing land for human purposes and pollutiing environments with our waste.
Human skin color likely represents a locally adapted compromise between
the need to block UV radiation that destroys folate and the need to synthesize vitamin D.
Which of the following statements about cells is true?
All cells have internal structures with similar biochemistry.
Bacteria are ________ cells.
prokaryotic
________ cells lack a membrane-enclosed nucleus.
Prokaryotic
Which of the following statements about internal membranes in eukaryotic cells is false?
In eukaryotic cells, internal membranes are made primarily of starch molecules
Which of the following statements about cellular metabolism is false?
Cellular metabolism occurs in animal but not plant cells.
It is best to have a diet that is mostly fresh whole food. Why?
The body is made up of more than 60 elements and hundreds of molecules that are most complete if they are direct from nature
The function of mitochondria is
cellular respiration.
Which of the following statements regarding photosynthesis and cellular respiration is true?
Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria.
The processes of photosynthesis and cellular respiration are complementary. During these energy conversions, some energy is
lost in the form of heat.
The overall equation for the cellular respiration of glucose is
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.
Individual prokaryote cells are about ________ eukaryote cells; collectively, all prokaryote cells on Earth ________.
one-tenth as big as . . . weigh about ten times as much as the total mass of eukaryote cells
Prokaryotes
sometimes have folded internal membranes that are important in cell respiration and photosynthesis.
The three diseases that represent high-priority threats as biological weapons today are
anthrax, plague, and botulinum toxin.
Prokaryotes are important for
digestion in cows and deer
decomposing dead organisms
fermenting yogurt and cheese
What is NOT true of a virus?
It reproduces on its own through fission
HIV is a disease caused by
virus
All life is related. The BEST evidence is
Very similar cell chemistry
Structure in the living world is organized into hierarchical levels. Which of the following lists these from least inclusive to mostinclusive?
molecule, cell, tissue, organ, organ system, organism
What is NOT true about water in our body?
the best source is bottled water because it is pure H2O
Carbohydrates are needed for cell energy. What is the most nutritious source of carbohydrates in the diet?
fruit
Bacteria are fairly easy to kill with antibiotics mostly because they have
a cell wall chemicallly different than our cells
What does a vaccine do?
stimulates our immune system to make antibodies
Viral diseases are best fought with
staying healthy and vaccines
Which of the following can cause a disease (like Mad Cow disease) even though it is just a protein and not a cell?
prion
A healthy immune system can kill
virus
bacteria
all of these
none of these
cancer cells