How do planarians survive without a circulatory system? What will be an ideal response?
Concepts to Consider: Planarians are usually fairly small animals. The small size maximizes the ratio
of surface area to body volume, which maximizes diffusion. Maximizing surface area is also
accomplished through the flat body shape of these animals. Internally, diffusion of body fluids to
various regions of the body is accomplished through a highly branched gut, which maximizes the
surface area with which it comes in contact. Combined, these features allow for efficient gas exchange,
waste removal, and the delivery of nutrients, which are some of the functions carried out by a
circulatory system.
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What is the ploidy of an organism that is 7n, where n = 5?
A) 5 B) 7 C) 12 D) 35 E) 57
The term used to describe bacteria that have a spherical shape is
A. vibrio. B. bacillus. C. coccobacillus. D. coccus.
Which of the following causes infectious sores on the mucous membranes of the mouth that occur during times of stress?
A) Herpes virus B) Escherichia C) Prions D) Listeria E) Bacillus anthracis
The habitats most favorable for the growth of legumes in symbiosis with nitrogen-fixing bacteria are
A. calcium-poor soils. B. nitrogen-poor soils. C. phosphorus-poor soils. D. manganese-poor soils. E. potassium-poor soils.