Sponges biggest hardship is being in constant competition with ________
a. sunlight
b. food
c. calcium carbonate
d. space on solid materials
d
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Which kingdom would include an organism that is multicellular and makes its own food?
A) kingdom Animalia B) kingdom Fungi C) kingdom Plantae D) kingdom Protista
Scientific discoveries have had great impact in human history. The people who make these discoveries and the circumstances that surround these discoveries are very important to our understanding of science. Can you identify the individuals as they might have described themselves?
a. I am a seventeenth century shopkeeper from Holland. My hobby involves hand-polishing glass to make lenses, some of which can magnify almost 300-fold. I was the first to observe living cells and am known as the "Father of Microbiology." b. I was the Curator of Instruments for the Royal Society of London in 1665. I developed a crude microscope that could magnify around 30-fold. I examined plant material and observed many small chambers that I called cellulae. c. At the University of California, Berkeley, I worked with radioisotopes. In the late 1940s and early 1950s, I used carbon-14 to identify the most common pathway for photosynthetic carbon metabolism. d. We worked out the double helix model of DNA structure in 1953. We later received the Nobel Prize for this work. e. I am a nineteenth century German chemist. By synthesizing an organic molecule from inorganic components, I dispelled the idea that biological processes were exempt from the laws of chemistry. f. My colleague and I worked with bacterial viruses. We were able to demonstrate that DNA–not protein–was the genetic material of the cell. g. I am a Swedish scientist. I developed the ultracentrifuge to determine sedimentation rates of proteins. The ultracentrifuge was later used to isolate subcellular fractions.
The highest tariff rates in U.S. history were the result of the
a. Reciprocal Trade Agreements Act of 1934. b. Hawley-Smoot Tariff of 1930. c. Tokyo Round of 1970. d. Uruguay Round of 1986.
Using the characteristics that define life, compare and contrast a plant, a bacterium, and a salt crystal. What will be an ideal response?