Biology 1108 UCONN final review

population (n)

number of individuals

allele frequency

number of occurrences of the allele divided by twice the number of individuals (2n)

If a population is not in Hardy-Weinberg equilibrium, we can conclude that

evolution has occurred because one of the assumptions has been violated

Hardy-Weinberg equation

p^2+2pq+q^2=1, where p=dominant allele and q=recessive allele

Conditions of Hardy-Weinberg Equilibrium model

1. no differential survival or reproductive success

2. no migration

3. no mutation

4. large population

5. no mate choice

stabilizing selection

maintains status quo and acts against extremes (i.e child birth weight)

disruptive selection

acts in favor of extremes

genetic drift

random change in allele frequency

gene flow

movement of alleles between 2 populations

novel adaptation

evolved adaption within a population

Three populations of crickets look very similar, but the males have courtship songs that sounds different. What function would this difference in song likely serve if the populations came in contact?

A prezygotic isolating mechanism

How are two different species most likely to evolve from one ancestral species?

Allopatrically, after the ancestral species has split into two populations

Hybridization

-involves the transfer of genetic material between members of similar species

-occurs in plants more often than animals

-can result in infertile offspring

ring species

share DNA indirectly through populations where interbreeding occurs

pre-zygotic

before fertilization (behavior, ecological, time, )

post-zygotic

after fertilization (genetic incompatibility)

sympatric speciation

the result of disruptive selection

polytomy

graphical depiction of the relationships between the common ancestor node with no resolution among descendant groups

monophyletic group

includes only an ancestor and all descendants of that ancestor

fossil contributions

1) time calibration

2) records of extinct species

3) correlation between evolution and earth history

The level of genetic variation in humans is typically ________ than other species

lower

Where did Homo Sapiens evolve

Africa

Why do we think male Neanderthals mated with non-African ancestral Homo sapiens?

because Neanderthal nuclear DNA sequences are present in the human gene pool and Neanderthal mtDNA sequences are not

How can two cells of a complex multicellular organism have the same genome, but markedly different structures and functions?

Different genes are expressed in different cells

neotony

retention of juvenile characteristic in an adult

Homo naledi

has hands and feet that are very human-like even though his pelvis and shoulders are much more primitive

cytoskeleton

scaffolding of dynamic proteins

Why do mitochondria and chloroplast have relatively small genomes?

Over time, much of their nucleic acid has migrated to the host cell nucleus.

How old are the fossils of eukaryotes?

1.8 billion years

Starvation

causes amoeboid feeding cells of cellular slime molds to aggregate into a large multicellular "slug"

complex patterns of gene regulation

enabled eukaryotes to evolve complex life cycles and programs of multicellular development

phagocytosis

engulf, package, transport, and digest food particles

derived cyanobacteria

chloroplasts

Cells in the interior of complex multicellular organisms are able to respond to environmental signals through...

receptors for signals sent from exterior cells that relay information about environmental changes

Simple multicellular eukaryotes

-cells are able to adhere to one another

-cells are capable of a wide range of functions

-the loss of one or more cell doesn't lead to the death of the organism

The acquisition of traits necessary for complex multicellularity occurred independently in plants and animals, but took place in a specific order. In what order did these processes evolve?

cell adhesion molecules, a mechanism of communication, bulk flow

meristems

enable plants to develop complex anatomical structures despite the fact that plants can not move

localized regions of actively dividing cells

What is believed to be the major event that led to the appearance of large complex animals on Earth?

increase in atmospheric oxygen

bulk transportation

the means by which molecules move through organisms at rates beyond those possible by diffusion across a concentration gradient

gap junctions

animal cell communication

For the "light" reaction to occur, an electron donor (_______) and an ultimate receptor (________) are needed.

water, NADP+

H2O

oxidized in the photosynthetic reaction

Horizontal gene transfer

happened first for the evolution of photosynthesis

rubisco

most abundant protein on earth

CO2

initial carbon input for the Calvin Cycle

photosynthesis

-biochemical process for building carbohydrates from sunlight, water, and CO2 taken from the air

- CO2 + H2O ---> C6H12O6 + O2

chloroplasts

where photosynthesis occurs

Calvin Cycle

uses carbon dioxide to synthesize carbohydrates

1. carboxylation > 2. reduction > 3. regeneration

carboxylation

the first step of the Calvin Cycle, addition of CO2 to the 5 carbon compound, RuBP, is catalyzed by Rubisco

reduction

the second step of the Calvin Cycle, NADPH transfers high energy electrons

If the two guard cells of a stoma decrease their concentration of potassium (K+) ions, what will happen to the corresponding pore?

The pore will close, preventing the diffusion of CO2 out of the leaf.

veins of leaves

1) composed of xylem and phloem

2) continuous with vascular bundles in the roots and stems

3) finely branched to be in close contact with photosynthesizing cells

root hairs

-produced by roots in order to increase surface area, allowing for greater access to nutrients in the soil

-develop after cells elongate

If water molecules (H2O) suddenly stopped forming hydrogen bonds with one another, how would water transport in vascular plants change (if at all)?

It would stop, as water transport relies on H2O molecules being connected by hydrogen bonds.

Roots elongate continuously in order to....

mine new regions of soil for minerals

In a sunflower population, a mutation arises that results in vessels 4 times wider than wild-type. The mutants will have _________ water-transport capacity, but will also be more susceptible to _________.

higher, cavitation from freezing

leaves

-responsible for gas exchange between the environment and the plant

-responsible for photosynthesis

-responsible for transpiration (moisture loss)

-have a waxy cuticle and stomata to monitor CO2 gain and water loss

xylem

long distance transport of water from roots to shoots

found in vascular bundles

cell types of xylem

1) tracheids

2) vessel elements

3) parenchyma

4) fibers

phloem

long distance transport of sugars, amino acids, and other compounds

cell types of phloem

1) sieve tube members

2) companion cells

3) parenchyma cells

4) fibers

zone of maturation

where roots absorb nutrients

rhizobia

nitrogen-fixing soil bacteria

primary growth

shoot and root apical meristems give rise to cells that become a part of the primary plant body

growth in length/height

gymnosperm and angiosperm seeds

contain a diploid (2n) embryo

What is the most likely reason that vascular tissues are present only in the sporophyte generation?

There is no advantage for the gametophyte to grow tall because gametes must be produced near the ground where the water needed for their free-swimming sperm is most likely to be found.

angiosperm fruit

derived from the wall of the ovary

dispersal

-reduces competition for resources

-allows genotypes to colonize larger areas

-allows for escape from pathogens and parasites

seed producing plants

-male gametes are never exposed to the environment

-the gametophyte is reduced to a few cells dependent on the sporophyte

You purchase two identical houseplants and place them side by side on your windowsill. You water both plants equally. One plant, plant a, you leave alone. On the other plant, plant b, you pinch off the top of the growing stem, effectively removing the apical meristem. Which of the following would you expect to occur?

plant b will be much bushier, with growth of many lateral branches

A woman is growing an African violet on her windowsill. After several weeks, she notices that the plant is leaning toward the right, in the direction of the window. In the stem(s) of her African violet, where would you expect to find most of the auxin?

on the left (shaded) sides of stems, facing away from the window

If you pull a small piece of bark off a tree, and then look at its inside surface, what tissue are you looking at (ignore any remaining cells of vascular cambium that may be left)?

phloem

In your vegetable garden you are growing yams. Yams are modified root tissue from the plant. What is the function of the yam for the plant?

it stores sugar for the plant

auxin

synthesized in shoot apical meristems

inhibits outgrowth of axillary meristems

stimulates formation of root meristems

induces cell wall extensibility

gibberellic acid

stimulates stem elongation and cell division

cytokinins

stimulates cell division

acts synergistically with auxin

ethylene

reduces cell elongation

triggers fruit ripening

apical dominance

plant needs to avoid leaf overlap and shading

wind

causes shorter, wider stems to develop

bud scales

surround meristem and protect from ice and water

A researcher comes across a plant that has been infected by a pathogen. As a result of the infection, the plant has undergone a systemic acquired resistance (SAR) response and has also generated several siRNAs. Based on this response, what type of pathogen most likely infected the plant?

a virus

You may have heard that monarch butterflies (and their caterpillars) are "poisonous" to many predators. What makes these insects so toxic?

they store cardenolides from milkweeds

Recall that the bullhorn acacia forms a symbiosis with P. ferruginea ants. A researcher takes an acacia seed and plants it in an area without P. ferruginea. What will happen to this acacia plant?

the plant won't have any defenses and will be eaten by herbivores.

A seed from a yew tree germinates on the forest floor. During the first few months of its life, the sapling dedicates most of its resources to increasing in height rather than producing the defensive compound taxol. What is this allocation of resources an example of?

a trade-off

What allows a plant to mount an immune response against a specific pathogen?

avirulence (AVR) proteins formed by pathogens

resistance (R) proteins in the plant cytoplasm

epidermis

first line of plant defense

basal immune system

general defense response

plant recognizes molecular trait of pathogen

specific immune system

specific resistance

AVR proteins recognized

hypersensitive response

layer of dead cells around infected area prevent pathogen from spreading

What describes a fern you see when you walk in the woods?

a diploid sporophyte

multicellular gametophyte of a bryophyte

haploid

green algae

-wide variety of growth forms, ranging from single cell to multicellular

-occur in a variety of habitats

-have chlorophyll a, chlorophyll b, cellulose in their cell walls, and starch as a storage product

zygote

divides by meiosis before releasing spores

bryophytes

-no true roots

-no true vascular tissue

-free-living stage is haploid

-sexual reproduction depends on water

When did the first vascular plants appear?

420 million years ago

gymnosperms

-group of land plant that was dominant until angiosperms began rapid speciation

-include ginkgos, cycads, conifers, and gnetophytes

-produce seeds

Ginkgo trees are popular in urban areas because they thrive under varied conditions and have attractive leaves, especially in the fall. The only drawback is that the fleshy seeds have a disagreeable odor. Consequently, ginkgo trees that produce pollen are preferred over those that produce the fleshy, smelly seeds. Therefore, what is true?

Ginkgo trees that release male gametophytes are preferred over trees that are pollinated.

multicellular gametophytes of ferns

haploid

ginkgos

limited to a single species

Antibiotics work by inhibiting the synthesis of petidoglycan, a component of the bacterial cell wall. Considering this mechanism, what is a possible mechanism of action for anti-fungal drugs?

inhibiting the synthesis of chitin in fungi