Biology Chapter 10 Homework
What is the concern about using antibacterial and antimicrobial soaps?
The use of any chemical that kills bacteria can eventually lead to resistance to that chemical in the population of bacteria.
Dr. Doebley and his team compared the DNA sequence of maize to that of a number of teosinte varieties from throughout Mexico. What did their analysis reveal? Select all that apply.
maize originated from a variety of teosinte that existed about 9,000 years ago maize is most closely related to a teosinte variety in the Balsas region of Mexico
In the projected video showing the growth of bacteria, why did the bacteria grow up to the edge of the area with antibiotics, pause, then continue to grow across the area with antibiotics?
A few bacteria experienced random mutations in their DNA, which allowed some of them to grow even though antibiotics were present
Which of the following correctly describes what the video referred to as a "microbial cure"?
Antibiotics are used to kill all of the infectious bacteria in a person.
A particular antibiotic kills 99% of a bacterial population. What will be the result of the continued application of this antibiotic?
Over time, the antibiotic will become less effective at killing the bacteria.
In the video, what does the UK's Chief Medical Officer suggest for promoting the development of new antibiotics?
encouraging big pharmaceutical companies to start investing again in new drug research and development
Which of the following contributes the LEAST to the problem of antibiotic resistance?
taking the entire course of antibiotics as prescribed by the doctor
George Beadle concluded that teosinte is the likely ancestor of maize (corn), even though the two plants appear very different. What evidence did Dr. Beadle collect that led to his conclusion?
teosinte and maize have similar chromosomes. teosinte and maize can produce fertile hybrids
Over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?
Bacteria that happen to have natural resistance to antibiotics survived and reproduced.
By crossing teosinte and maize through two generations (each producing F1 and F2 offspring), Dr. Beadle was able to estimate how many genes were involved in determining the major differences between the two species. F2 Offspring Ratios as Predicted by Mendelian Genetics Genes involved Ratio of offspring expected to look like teosinte Ratio of offspring to look like maize Ratio of offspring expected to look like a mix of teosinte and maize 1 1/4 1/4 2/4 (1/2) 2 1/16 1/16 14/16 (7/8) 3 1/64 1/64 62/64 (31/32) 4 1/256 1/256 254/256 (127/128) 5 1/1024 1/1024 1022/1024 (511/512) Dr. Beadle planted about 50,000 seeds from the second cross. About 100 of these F2 offspring looked like teosinte, and about 100 like maize. Based on this result, how many genes did Dr. Beadle conclude could account for the differences between maize and teosinte?
four or five
