Why are apple trees propagated asexually?
a. the process is much easier than growing them from seeds
b. it is the only way to grow the same reliable quality of apple
c. asexual propagation introduces genetic variation that makes the trees hardier
d. asexually propagated apple trees are more disease resistant
e. more than one of these is the reason why apple trees are asexually propagated
ANSWER: b
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Pesticide use has grown a great deal in the past century, and similar to the plant-herbivore evolutionary "arms race":
A. increased use of pesticides is leading to increased rates of resistance. B. widespread chemical treatments pose little concern because they wipe out all existing herbivores. C. pesticides are killing pests and their predators, reducing the overall level of herbivory in crop plants.
A graduate student wants to clone a particular gene into a plasmid. The sequence includes AluI and BamHI sites on both sides of the desired fragment
AluI cuts symmetrically directly between the G and C nucleotides in a palindromic 5' AGCT 3' sequence. BamHI cuts asymmetrically directly between the G and G nucleotides in a palindromic5' GGATCC 3' sequence. Which of the two restriction endonucleases should the graduate student choose, and why? A. BamHI to cut both sides-since it cuts asymmetrically, it'll leave the sticky, cohesive single-strand DNA ends that will make it easier to ligate into a BamHI-cut plasmid DNA sequence. B. AluI to cut both sides-it's always easier to ligate together blunt ends of DNA. She should also use AluI on the plasmid she wants to put the fragment into. C. BamHI on the fragment, and AluI on the plasmid-this will give her the matching sequences to anneal/ligate together on the fragment/plasmid combination. D. BamHI on one side of the fragment, and AluI on the other side-this would keep the fragment from sticking right back to where it was cut out from in the original DNA.
As electrons are passed through the electron transport chain, the series of redox reactions generates free energy that is used for what purpose?
a. The free energy is used to pump hydrogen ions (protons) across the mitochondrial membrane. b. The free energy is shuttled to glycolysis to aid in the metabolism of glucose. c. The free energy is used to manufacture enzymes to regulate cell metabolism. d. The free energy is stored and used to drive cell processes when ATP is in short supply.
Determine the mode of inheritance of the trait in the pedigree above
1.autosomal dominant
2.sex-linked recessive
3.autosomal recessive
4.X-linked dominant
5.X-linked recessive
6.mitochondrial inheritance
7.Y-linked inheritance