Evolution chapter 10 pt1

This figure from Coleman e al, 1990 shows the relationship between coefficient of variation(a measure of variation; in this case the growth of radish plants from multiple different experiments and the concentration of sulfur dioxide (a stress) the plants were grown in?

What is the major point of this graph?

• Variation in growth increases with the degree of stress

• Stress doesn't impact growth

• There is no point

How might this relate to natural selection?

• The phenotypic variation in radish growth is elevated under increasing levels of sulfur dioxide (stress). If the phenotypic variation is heritable, and the growth responses are related to reproductive success, then increasing stress, increases variation, which could lead to rapid selection

• The phenotypic variation goes down with stress. If the stress continues than the radishes will be extirpated with no natural selection

This graph shows the relationship of a constitutive heat shock protein (HSP 60), and one that isonly induced by stress (HSP 24) in corn plants grown under different nitrogen levels in the soil, before and after a heat shock. Controls represent plants that were not exposed to a heat shock?

What are two points from figure a?

• In the control plants, the constitutive level of HSP60 was higher (nearly double) in high nitrogen grown plants.

• there was far greater production ofHSP60 in high N grown plants than low N grown plants after a heat shock

• The graph is indecisive

• HSP isn't impacted by nitrogen

This graph shows the relationshipof a constitutive heat shockprotein (HSP 60), and one that isonly induced by stress (HSP 24) incorn plants grown under differentnitrogen levels in the soil, beforeand after a heat shock. Controlsrepresent plants that were notexposed to a heat shock?

What is the main point fromfigure b?

• HSP 24 levels rapidly increasedduring the heat shock, with high Nplants reaching a higher peak, andwith high N plants maintainingvastly higher levels of HSP 24 for aperiod of 100 hours after the heatshock

• In the control plants, theconstitutive level of HSP60 washigher (nearly double) in highnitrogen grown plants.

This graph shows the relationship of a constitutive heat shock protein (HSP 60), and one that isonly induced by stress (HSP 24) incorn plants grown under different nitrogen levels in the soil, before and after a heat shock. Controls represent plants that were not exposed to a heat shock?

What hypothesis was being tested, and would these data lead you to reject that hypothesis?

• The hypothesis was that there is an N cost of inducing HSP proteins. Since low N plants induced much lower levels of HSP 24 and HSP60, and the HSP levels were always higher in high in plants under control condition, the data suggest there may be an N cost

• HSP 24 levels rapidly increasedduring the heat shock, with high Nplants reaching a higher peak, andwith high N plants maintainingvastly higher levels of HSP 24 for aperiod of 100 hours after the heatshock

• In the control plants, theconstitutive level of HSP60 washigher (nearly double) in highnitrogen grown plants. And, therewas far greater production ofHSP60 in high N grown plants thanlow N grown plants after a heatshock

How are selective pressures different for three-spinedsticklebacks in lakes compared to the sea?

• They have fewer predators in lakes.

• They have more predators in lakes.

• They find fewer prey in lakes.

• They find more prey in lakes.

Why do three-spined stickleback fish with low-Eda alleles havean advantage in freshwater over sticklebacks with high-Edaalleles? There are fewer predators in lakes.

• Low-Eda fish stop growing at smaller body sizes, which allows them to survive with less armor.

• Low-Eda fish use their available energy to grow faster andadd body mass instead of armor.

• Low-Eda fish can grow heavier armor to defend against thepredators in freshwater

• Low-Eda fish can produce both large bodies and heavy armor when food is abundant.

Why did the increase in human agriculture produce aparallel increase in the occurrence of insects?

• Insects were forced to use new food sources as farmsreplaced their original habitats

• More human blood was available to insects as humanpopulations increased.

• A local abundance of nutritious crops improvedreproductive success in insects.

• Insects have always been diverse, and human agriculture did not influence this

How have ryegrass and goosegrass evolved resistance to glyphosate?

• by changing a single amino acid in the enzyme EPSPS

• by making extra copies of the EPSPS enzyme

• by blocking the EPSPS enzyme

• by growing a waxy cuticle to prevent uptake of the chemical

Why have so many species of weeds become resistant toglyphosate?

• Glyphosate persists in the environment for a long time.

• Many farmers used glyphosate as their only herbicide foryears

• Glyphosate only targeted weeds and did not affect anycrop plants

• Plants repeatedly sprayed with glyphosate develop tolerance for it