Describe three trends that have allowed the human population growth rate to soar in the past two centuries
What will be an ideal response?
Three trends promoted the large increases. First, humans expanded into new habitats.
Second, they developed technologies that increased the carrying capacity of their habitats. The invention of agriculture, harnessing energy in fossil fuels to operate machinery, invention of fertilizers and pesticides all increased crop yields and the carrying capacity of earth.
Third, they sidestepped limiting factors that typically restrain population growth. There were improvements in food safety, sanitation, and medicine. People began to pasteurize foods and drinks, heating them to kill harmful bacteria. They also began to protect their drinking water. Advances in sanitation also lowered the death rate.
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Alternative RNA splicing _____
A) is a mechanism for increasing the rate of transcription B) can allow the production of proteins of different sizes and functions from a single mRNA C) can allow the production of similar proteins from different RNAs D) increases the rate of transcription E) is due to the presence or absence of particular snRNPs
Did Pangea or Gondwana form first?
What will be an ideal response?
In the presence of predators, some tadpoles grow larger and more colorful tails to avoid lethal strikes to the head. This ability to respond to the environment via morphological traits is known as
A) phenotypic plasticity. B) outcrossing. C) dioecious. D) K-strategy.
If the frequency of one allele in a population is 0.7 in a population with two alleles at a particular locus, what is the frequency of the alternate allele?
A) 0.09 B) 0.21 C) 0.30 D) 0.42