5/7/12 8:24 PM

Exam 1:

Why do most scientists and historians give Darwin more credit than Wallace

regarding their contributions to evolutionary theory?

Darwin provided more extensive evidence in support of evolution

Darwin developed his ideas before Wallace did

Which of the following best describes natural selection?

The differential survival and reproduction of individuals

Which of the following statements is false?

Evolution and natural selection are interchangeable terms

What is the maximum number of alleles that a given human adult (with 23

pairs of chromosomes) can have at any particular genetic locus?

2

What was Darwin’s explanation for the evolution of bright colors and other

apparently useless (and potentially deleterious) but conspicuous characters

in males of many species?

Sexual selection

Which of the following modes of selection leads to a reduction in variation

but no change in the mean?

Stabilizing selection

A haploid cell is a cell

Containing only one copy of each chromosome

If a protein-coding gene is found to have a higher rate of non-synonymous

substitutions than synonymous substitutions, this suggests to molecular

biologist that selection on this gene is acting

Rapidly

Information sources used by Watson and Crick to determine the structure of

DNA included

X-ray crystallography of double-stranded DNA

Eusociality

Overlap of generations

Reproductive division of labor (with or without sterile castes)

Cooperative care of young

Vestigial organ – an organ or structure that has lost most or all of its

function, and descent modification is observable first elaborated by Darwin

that all organisms are related through descent from an ancestor in the

remote pasts.

The presence of a vestigial organ suggests the structure/organ had been

functionally important in the past and is being further modified (albeit

atrophying) as it is passed to descendant species. It is hard to explain such

structures for any process other than descent with modification and is

considered evidence that such a process occurs.

Hamilton’s Rule:

C = cost of the altruist (in fitness) to the altruist (or actor)

B = benefit (in fitness) to the altruist (or actor)

R = relatedness among the altruist and the recipient

o C/B < R, RB – C >0

R of Brothers = 0.5

C = 1

1/B < 0.5, B = 2 or more

Parental care in species that exhibit sex role reversal is done by the male

In these cases of sex role reversal, intrasexual selection occurs among

females and intersexual selection occurs among males

Intrasexual selection usually among males since they compete for a

female

For the clade shrimps, gorillas and humans, are hair, DNA and endoskeleton

characters that are:

Pleisiomorphies

If the frequency of a dominant allele is 0.6 in a population that is in Hardy-

Weinberg equilibrium, what is the expected genotypic frequency of the

recessive homozygotes?

Q = 1 - 0.6, q=0.4, q2 = (0.4)(0.4) = 0.16

Why is cross fostering a powerful tool in understanding the genetic

component of a trait. What feature of a phenotype does it serve as a control

for?

Phenotypes are the result of interactions among both genes and the

environment. Cross-fostering randomizes the environment a trait is

expressed in allowing estimates to be made of the genetic

contribution to that trait. For many species, offspring of parents with

known phenotypes are reared with parents with different

phenotypes. If these cross-fostered offspring exhibit the trait similar

to their biological parents and dissimilar from their foster parents,

the contribution of the genetic basis to the trait will be greater than

if the offspring develops traits dissimilar to their biological parents

and similar to their foster parents.

Lahdenpera et al’s study

The study examined the effects of help by a post-reproductive

mother to her daughter on the number of children born, the time

interval between children, and age of the mother when the first

child was born. Most of the comparisons relied on the grandmother

either being dead or alive. However, this does not mean that

something about the grandmother being alive, rather than help,

was the casual factor. Figure C shows data that controls for this

problem. If grandmothers have moved away they are alive but

cannot help rear grandchildren because they live too far away. That

the same pattern of number of grandchildren born is seen in the

comparison of dead vs. alive is seen in dispersed vs. local suggest

that it is help from the grandmother that is important.

Under what environmental conditions does the greatest change in the body

mass occur?

Drought associated with unusual warm temperatures in the

southern Pacific Ocean

Exam 2:

If the half-life of a radioactive substance is 600 years, what fraction of the

original material is left after 1,800 years?

1/8

The first person to put forth the idea that Earth’s continents are in continual

but slow motion was

Alfred Wegener

Which of following leads to the formation of mountain ranges?

One lithospheric plate sliding under another

Which continent was most likely affected the most by the meteor strike that

led to the demise of non-avian dinosaurs?

North America

As compared to anaerobic metabolism, aerobic metabolism is advantageous

to cells because it

Proceeds at a more rapid rate

Is more efficient

Permits the growth of larger, more complex cells

Larger single-celled organisms require a higher oxygen concentration than

smaller ones do because the larger cells

Have a lower surface area-to-volume ratio

The most dramatic mass extinction in Earth’s history, which destroyed about

96 percent of the species

Occurred at the end of the Permian

Bilaterally symmetrical animals can be divided into two major groups that

separated during the Cambrian. These two lineages differ fundamentally in

their

Early embryological development

Which of the following features is a synapomorphy of the animals?

Similarities in their hox genes

Cephalization is most commonly associated with

Bilateral symmetry

Sponges differ from other animals in that they

Do not form true organs

Which of the following statements about exoskeletons is true?

They are highly efficient means of anchoring muscles, thereby

providing more efficient movement

They provide protection from predators

They must be shed for the animal to grow, and during the shedding

period the animal is vulnerable to predators

They provide support for walking on dry land

Animals with thin cuticles are generally restricted to moist habitats because

The thin cuticle causes water to be lost across the body surface

Which of the following groups contains the largest number of species?

Arthropods

A few species of frogs and salamander are _____, which means they give

birth to well-developed young.

Viviparous

Protobiont was the stage in the origin of life prior to the most common

ancestor to all of life. It is a hypothetical stage that can be studied only by

experimentation. Protobionts are thought to have been enclosed by a

membrane or a membrane-like structure, and had the capability to

metabolize and reproduce. Protobionts probably contained RNA as an

information molecule.

Universal Common Ancestor is the organism of all life on the earth today

descended from. It is a stage after the protobiont stage.

Prokaryotes refer to species in the Archaea and Bacteria, but not to single

celled or multi-celled Eukarya.

Germ cells give rise to the gametes (sperm and ova) and are passed on to

the offspring so are immortal. Somatic cells (body-organs) don’t get passed

on to the offspring, but function to ensure that the germ line makes it to

following generations.

You find that there are 4 separate genomes in a cell

The host is a heterotroph

There are at least 2 unique types of mitochondria present

This is a case of secondary endosymbiosis

The chloroplasts is in the endosymbiont

Exhalation and inhalation of a monotreme (animals that lay eggs)

Nitrogen – no change or decreases a bit

Oxygen – decreases

Carbon Dioxide – increases

Water – increases

What group of deuterostomes does not have a notochord in any of its life

stages?

Echinodermata

Polymerase Chain Reaction is possible because of the study of prokaryotes

that live in what kind of environment?

Hot springs, hyperthermic environments, (extremeophiles)

Name one autotrophic organelle that is a result of primary endosymbiosis

Chloroplasts

What is one evolutionary “cost” of recombination?

Cost of sex 1: male production in sexual populations entails an

ecological cost of sex, because males do not produce offspring

Cost of sex 2: decreased relatedness in sexuals

Cost of sex 3: recombination breaks up the non-random

associations between alleles at different loci.

o If these non-random associations were generated by selection

in the previous generations they should be well-adapted to

the local environment. Recombination shuffles these good

combinations of alleles.

Horizontal gene transfer in prokaryotes can occur by what two DNA

exchange processes?

Transduction (via plasmids), transformation (acquiring DNA directly

from the environment) or conjugation

Name 2 types of plastids and indicate if they are autotrophic or not.

Chloroplasts (autotrophic), rhodoplast (autotrophic), apicoplasts

(not autotrophic)

What repair mechanism does DNA have that is not available to RNA and that

probably explains why DNA is the primary information molecule of life of all

life today?

DNA has a more stable conformation, that is, it has a long half-life

so it doesn’t degrade as easily. Additionally, DNA has self-correcting

mechanisms that RNA lacks because the opposing strand can be

read if there is a break in one strand. With uncorrected mutations,

RNA wouldn’t hold up for too long. DNA has proofreading and

correcting enzymes that are active during replication

How did the origin of photosynthesis profoundly change the mutagenic

environment on earth?

The early atmosphere lacked free oxygen and for over a billion

years life was only represented by anaerobic prokaryotes. However,

once photosynthesis evolved, atmospheric oxygen increased

rendering the earth toxic to anaerobes. Free oxygen created the

ozone layer which now deflects a large proportion of mutagenic

radiation back into space. Reduced mutation rates were likely

important for the eventual development of larger genomes,

eukaryotic cells and later on, multicellular organisms.

Exam 3

Which of following is not a key trait of the specific immune response?

Rapid response

Cruise ship passengers find themselves fighting flulike symptoms for the first

four or five days of their trip, but eventually they recover and enjoy their trip.

Which of the following is the last defensive component involved in their

recovery?

Antibodies

Which of the following was not a change that accompanied the transition

from the australopithecines to Homo habilis?

Dispersal of populations to Europe and Asia

The humoral response in insects is initiated when bacteria or fungi are

detected in what part of the body?

Hemolymph

Once detected, the above insect pathogens initiates a cascade of

biochemical events in what specialized cells of the hemolymph?

Fat cells

What species of homo had the greatest average cranial capacity?

Homo neanderthalensis

Pollen is a gametophyte

People that hug trees are hugging a sporophyte

Meiosis occurs in the sporophyte

The dominant multicellular phase of a moss is gametophyte

Explain how structures and cells involved in oxygen transport differ among

insects and spiders.

Insects breathe through the tracheal system, a system of tubes

branch to every cell of the body and are open to the outside of the

body through openings called spiracles. The smallest ends of the

tubing system are called tracheoles. The hemolymph of insects is

not involved in respiration

In contrast, spider hemolymph is involved in respiration. A

specialized molecule called hemocyanin (that is blue-colored

because the central element is copper) carries oxygen.

Which of the following statements about specific and nonspecific defenses is

false?

Specific defenses are typically the body’s first line of defense

Name two or three female tissues a pollen tube must grow through before

reaching the ova.

Stigma, style or carpel

How is supercooling different than melting point, and which of these do

antifreeze proteins influence?

Supercooling is when a fluid turns into a solid at a temperature than

its freezing point, and melting point refers to the transition of a fluid

from solid to liquid. Antifreeze proteins function by controlling how

large ice crystals can grow. In general terms, they provide a

nucleating source for ice to grow but their presence keeps ice

crystals small enough that they do not damage the cell. Organisms

that can tolerate supercooling may or may not have antifreeze

proteins (although often these organisms do). Importantly,

antifreeze proteins or the ability to undergo supercooling does not

change the melting point.

Where do bacterial restriction enzymes occur in the cell and how do they

avoid cleaving their own DNA?

Bacterial restriction enzymes (endonucleases) occur in the

cytoplasm. They are able to distinguish self from non-self DNA

because self DNA of bacteria is methylated.

What is the difference between acquired resistance and the hypersensitive

response in plants?

Acquired resistance and the hypersensitive response are both

related to immunity in plants. Hypersensitive response occurs when

a pathogen attacks a cell. The cells then releases chemicals that

trigger the infect cell from being isolated from nearby cells by

modifications of its cell wall. Infected cells are eventually killed. Just

before the cells dies it sends out compounds that trigger a signal

transduction to the rest of the plant. This initiates the production of

secondary plant compounds that help protect the plant from further

attack. This is the acquired response.

The tissue that provides nourishment for an angiosperm embryo is called

Endosperm

What is the importance of stomata and xylem to plant circulation.

To pull fluids from the roots to the leaves, plants use negative

pressure. Negative pressure is created by the maintenance of a

continuous column of water in xylem that end at the stomata, and

the affinity of water molecules to strongly adhere to one another.

Xylem is composed of dead, hard-walled cells that are aligned such

that they form a continuous tube that extends from the roots to the

top of the plant. Stomata occur in the leaves that if they are opened

or closed depends on the guard cells that surround the opening. If

stomata are open, water evaporates (transpires) into the

atmosphere and this pulls the continuous column of water up to the

top of the plant.

What force generates movement of sugar-rich water in the phloem tissue?

Gravity (down)

Capillary (up)

In the phloem, fluids move in both directions

Primates likely descended from small, arboreal _____ mammals

Insectivorous

B cells mature in

Bone marrow

Parathyroid cells are inhibited from synthesizing and releasing PTH when

circulating calcium levels are high. When calcium levels fall, the inhibition is

removed, PTH is synthesized and released, and calcium levels rise in the

blood until the parathyroid cells are once again inhibited. This process is an

example of

Negative feedback

Which of the following statements about the endocrine system is false?

Endocrine glands do not have ducts that lead to the outside of the

body