An evolutionary model of animal development indicates that _____
a. differentiation is positional within a zygote
b. homeotic genes are not universal among animals
c. homeotic genes are found only in fruit flies, where they are responsible for odd placement of appendages
d. new genetic lines are produced less by modification than by unique mutation
e. somites form as blocks of genes in cells randomly distributed throughout the body
ANSWER: a
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Amy receives a plant from her mother as a housewarming gift. She waters it regularly and keeps the plant on a windowsill that gets regular sunlight. Amy is determined to keep her mother's gift growing well and never moves the plant for fear of "hurting it," but the plant has started growing toward the window. Amy is puzzled as to why her plant is lopsided. What is happening to Amy's plant?
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How does a capsule help certain bacteria evade detection by the immune system?
A) Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. B) The capsule makes the bacterium too sticky to be phagocytosed by the immune cells. C) Capsules have the ability to destroy antibodies secreted by the immune system. D) The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.
What are you going to streak out on the EMB plate?
A) A sample from the food in the blender B) A sample directly from the food C) A sample from the 1:100 dilution sample D) A sample from the 1:1000 dilution sample
Vines use ____ to stay attached to support structures
a. spines b. bracts c. tendrils
d. needles e. bulbs