Unit 2 Test Flashcards
What causes extremely high levels of toxic chemicals in fish-eating birds?
Biological magnification
Which of the following describes carbon dioxide, methane, and water vapor re-reflecting infrared radiation back toward Earth
Greenhouse Effect
What is true about secondary consumers in an ecosystem?
They are fewer in number than are primary consumers
What’s a fundamental difference between matter and energy?
Matter is cycled through ecosystems; energy isn’t
In the nitrogen cycle, the transformation of gaseous nitrogen into nitrogen-containing compounds is performed primarily by
Prokaryotes
What best explains why there are seldom more than five tropic levels in a food chain?
Energy is lost from each tropic level
What is not a density-dependent factor that could act to limit population growth as population size increases?
Fire
Big-bang reproduction like that involving the agave plant is an example of?
Semelparity
What causes a sigmodial growth curve (S-shaped) to level off?
The population reaches the environmental carrying capacity
When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes
In biomes at different latitudes
Which of the following events might you reduction to occur if the tilt of Earth’s axis relative to its plane of orbit was increased beyond 23.5 degrees?
Summers in the US might become warmer, and Winters in Australia might become more severe
What would Dr. B want to do if he wanted his green beans to out grow his neighbors’?
Spray gibberellin on them
Which plant hormone, developing in an apical bud, either directly or indirectly inhibits the growth of lower axillary buds?
Auxin
What statement regarding phototropism is incorrect?
Auxin causes a decrease in growth on the side of the stem exposed to light
Transcriptional regulation and post-translational modification are most closely associated with which stage of a signal transduction pathway?
Response
What about reproduction in angiosperms is incorrect?
The generative cell undergoes one round of meiosis to form two polar nuclei
What types of plant cells are haploid?
Gametophyte main body and gamete
How many mitotic divisions are required for conversion of the megastore to the female gametophyte?
Three
What is true about plants?
Mitosis occurs in gametophytes to produce gametes, meiosis occurs in sporophytes to produce spores, ms the gametophyte is within the flower on angiosperms
Translocation of the phloem sap in a pant is primarily a result of
Positive pressure at the sugar source
Under what circumstances will stomata generally be open to allow transpiration to occur?
When guard cells are full of water
What effectively describes the Casparian strip?
It ensures that all water and dissolved substances must pass through a cell membrane before entering the stele
Which phenomena are involved in the ascent of xylem sap?
Adhesion, cohesion, and transpiration
What effect does “pinching back” have on a houseplant?
Makes the plant to grow fuller
Which causes an increase in the intensity of UV radiation reaching the Earth?
Depletion of the atmospheric ozone
The amount of chemical energy in consumers’ food that is converted to their own new biomass during a given time period is known as which of the following?
Secondary production
What typifies tropical rainforests?
Great biodiversity and usually highly stratified with at least five distinct layers, or stories, of vegetation
The benthic zone of aquatic environments is defined as the
Substrate at the bottom of a body of water
Slowing of stem elongation, thickening, and curvature of the stem to start growing horizontally are all part of a growing shoot’s response to
Ethylene
You are preparing a shipment abroad. To ensure the seeds won’t germinate, you treat them with what hormone?
Abscisic acid
What isn’t a mechanism utilized by plants to prevent self-fertilization?
Brightly colored bracts that replace petals
Which of the following cell types are present in the mature pollen grain?
Generative cel and tube cell
What is false about bulk flow?
It depends on the force of gravity on a column of water
What structure or compartment is not part of the plant’s apoplast?
The lumen of a sieve tube
Primary growth in plants is produced by the
Apical meristem
Vessel elements belong to which plant tissue type?
Vascular
The male gametophyte of an angiosperm is
Contained within the pollen grain
Where would you expect to find the littoral zone of a lake?
Shallow water area along the shore
Based on the ABC model, what would be the structure of a flower that had normal expression of genes C and B, but lacked expression of gene A
Carpel-stamen-stamen-carpel
What is the main force by which most of the water within xylem vessels moves toward the top of a tree?
Evaporation of water through stoma
What are the five events that explains the mass flow of materials in the phloem?
Leaf cells produce sugar by photosynthesis, sugar is transported from cell to cell in the leaf, diluted are actively transported into sieve tubes, water diffuses into sieve tubes, sugar moves down the stem
How many mitotic divisions are required for conversion of the microspore to the male gametophyte?
One
Which set of Coleoptera experiments show that auxin is a diffusible molecule?
Experiments that put a slice of mica or slice of agar between the severed tip and the rest of the coleoptile
If there are 75 births for a population of 300 individuals, what is the annual per capita birth rate?
.25
In the logistic equation, dN/dt =RN, r is a measure of the population’s intrinsic rate of increase. It is determined by what?
Birth rate and death rates
What is correct about bio geochemical cycling?
The phosphorus cycle is a sedimentary cycle that involves the weathering of rocks
