In some areas of the world where there are large numbers of pines, everything is covered in the spring with a yellow dust that turns out, upon examination, to be pine pollen. Why must conifers produce so much pollen, and why do we not see as much pollen
produced by a field of flowers?
What will be an ideal response?
Pines are wind pollinated and must produce large excesses of pollen because pollination takes place by chance. Field flowers are insect pollinated and therefore don't have to produce so much pollen because insects carry it to the exact location where it can grow. Gymnosperm pollen also is carried easily by air and deposited on surfaces, whereas pollen from many angiosperms tends to stay in the flower until specialized structures on pollinators pick it up and deliver it to a receiving flower.
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Mycoplasma pneumoniae
A. does not cause pneumonia despite its name. B. is one of the causes of atypical pneumonia. C. causes pneumonia only in conjunction with viral activity. D. causes pneumonia more often than Streptococcus pneumoniae.
Palindrome sequences are often found at mutation hotspots. Which of the following is a palindrome?
A) ATTACGGC B) ATATGCGC C) GATCCTAG D) GATCGATC
Inflammation helps to fight infection by
A) creating an environment in the body that is hostile to pathogens. B) producing antibodies that kill viruses and bacteria. C) limiting the number of phagocytes at the infection site. D) producing collectins, cytokines, and red blood cells.
These joints are somewhat moveable, but they do not have a fluid-filled capsule surrounding them
They have fibrous connective tissue covering the ends of the bones involved.
a. synovial joints b. cartilaginous joints c. fibrous joints d. non-fibrous joints e. antagonistic joints