Scenario In the Late 1800s, Charles Darwin and His Son Francis

question 39

Multiple Choice

Scenario
In the late 1800s, Charles Darwin and his son Francis conducted the first experiments on phototropism. Several years later, their work was furthered by Peter Boysen-Jensen, Arpad Paal, and Frits Went. Peter Boysen-Jensen separated the tip of grass shoots from the rest of the plant using either tiny blocks of agar (a gelatin) or a mica wafer (an impervious rock) . Like the Darwins, Boysen-Jensen noticed that the grass did not grow toward a light without its tips. However, when he separated the tip from the rest of the plant using agar, the grass would grow toward a light. The grass would not grow toward a light if the tip of the shoot was separated using a mica wafer. Arpad Paal cut off the tips of grass shoots that were growing in the dark. He placed these cut tips back on the shoots, but with only part of the tip covering the cut surface, and found that the plants grew, in the dark, in the opposite direction from the side with the tip covering it. Lastly, Frits Went removed the tips of many grass shoots and placed them on a large block of agar for a few hours. Then, he cut up the agar block, and was able to make grass shoots without any tips at all grow toward a light by putting these agar blocks on the cut surfaces of the shoots (i.e., no tips were placed back on the shoots, only the agar) .
-Boysen-Jensen also used the mica to separate a tip of a grass shoot only partially, by cutting the tip halfway and inserting a wafer of mica into the cut. If this experiment supported the Darwins' hypothesis, what would Boysen-Jensen have observed?

• A)The grass shoot would not grow toward a light.
• B)The grass shoot would grow toward a light when the mica wafer was on the side of the grass that was facing the light.
• C)The grass shoot would grow toward a light when the mica wafer was on the side of the grass that was shaded from the light.
• D)The grass shoot would grow toward a light no matter which direction the light was coming from.

Grasp the importance of biodiversity protection areas and habitat corridors in conservation efforts.

Understand the relationship between climate change, plant, and animal life cycles.

Analyze the effects of environmental changes on ocean and freshwater ecosystems.

Recognize the interplay between climate change, ecosystem services, and human well-being.

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Definitions:

Socio-ecological Framework

An analytical approach considering the interactions between social behavior and ecological environment in understanding species' dynamics.

Female Defense Polygyny

A mating system where males guard multiple females to ensure exclusive mating access, often seen in animals with defendable, clustered females.

Resources

Natural or man-made assets that organisms utilize for survival, including food, water, territory, and mates.

Polygynandry/Promiscuity

A mating system in which both males and females have multiple mating partners over a breeding season, promoting genetic diversity.