#Question id: 28296
#Unit 5. Developmental Biology
mechanisms of egg activation in sea urchins-Bindin receptor responsible for the activation of____
#Question id: 12544
#Unit 10. Ecological Principles
Use Figure to answer the following questions. Examine this food web for a particular terrestrial ecosystem. Each letter is a species. The arrows represent energy flow.
A toxic pollutant would probably reach its highest concentration in which species?
#Question id: 2296
#Unit 2. Cellular Organization
Small metabolites, such as sugar and ions, pass between plant cells via _______
#Question id: 12758
#Unit 10. Ecological Principles
Refer to the following experiment, which is designed to test the co evolutionary relationships among an unpalatable butterfly (the monarch), a palatable butterfly (the viceroy), and a butterfly predator (the jay). Monarch butterflies are reared on three diets: milkweed (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. Viceroy butterflies, mimics of monarchs, also are reared on three diets: willows (their natural food), cabbage, and cabbage treated with an extract from milkweed leaves. In trial 1 of the first experiment, adult butterflies reared on a particular diet are presented one at a time at 1-hour intervals to jays and the jays are allowed to feed. Each jay is fed until it refuses to eat the butterfly presented, but no more than 12 butterflies are presented to a jay during a particular test. Five birds are used for each test; therefore, up to 60 butterflies can be consumed for each diet test. The observer records the actual number of butterflies eaten. In trial 2, the experiment is repeated 2 weeks later. In the second experiment, the butterflies are reared on the same diets as in experiment 1. However, when they are offered to jays, some jays receive a monarch reared on milkweed before being offered the butterflies reared on the experimental diets; the other group of jays is first given a viceroy reared on willow before being offered the butterflies reared on the experimental diets. The initial butterfly offered is included in the total number eaten, but no more than 12 butterflies are presented to each jay.
The experimental design and the data indicate which of the following about the jays?
#Question id: 2580
#Unit 2. Cellular Organization
Following statements are regarding to mechanism of kinesin-1 movement.
A. Initially leading head tightly bound to the microtubule and not bound by any nucleotide, while the trailing head is weakly bound to the microtubule and has ADP bound.
B. Binding of ATP induces a conformational change causing the linker to swing forward and dock into the head. This motion swings the former trailing head to become the leading head.
C. Binding of ATP induces a conformational change causing the linker to swing forward and dock into the head. This motion swings the former leading head to become the trailing head.
D. When leading head releases ADP and coordinately the trailing head hydrolyzes ATP to ADP + Pi. Pi is released and the linker becomes undocked.
E. When trailing head releases ADP and coordinately the leading head hydrolyzes ATP to ADP + Pi. Pi is released and the linker becomes undocked.
Which of the following combination is correct?