一、构成性转录因子SP1对持家基因的调控作用 1、 Housekeeping(constitutive) genes(持家基因):细胞内的蛋白质编码基因,维持细胞的基本过程。 2、SP1结合于保 GGGCGG守性序列的GC丰富序列,该序列位于许多持家基因的启动子中

Plant nutrients Plant growth requires various nutrients Major nutrient elements: C,N, P trace elements: S, Si, Cl, I, and metallic elements(Fe, Mn, Cu, etc) The minor elements because of the low demand can Water y be supplied at adequate rates in natural

pH of a buffer and buffer capacity Example: For a buffer solution consisting of 0. 1 M acetic acid and o1M sodium acetate the ph of the solution is 4.75 HAc= i If an amount of hydrochloric acid equivalent to 10% of the acetate present, is added to the buffer, what is the new pH of the solution?

The discovery of the ozone hole The British Antarctic Survey has been monitoring for many years, the total column ozone levels at its base at Halley bay in the antarctica Monitoring data indicate that column ozone levels have been decreasing since 1977. This observation was later confirmed by satellite

Whether and climate Weather is the condition of the atmosphere in terms of temperature, humidity, winds and precipitation Climate is defined as the average weather over various time periods ranging from a few weeks to decades to geological timescales Whether and climate are ultimately determined by location, topography, and the exchange of radiant energy between the Sun, Earth, and space

Cloud albedo forcing: Cooling Shortwave Radiation The shortwave ays from the Sun are scattered in a cloud; many of the rays return to space. The resulting\cloud albedo forcing taken by itself

Book Ii Unit 10 Section A The Bermuda Triangle Phenomenon I Warm-Up Questions: 1. Have you ever heard of the Bermuda Triangle? Do you know its location? 2. What have you heard about it? 3. According to your idea, why things disappear in that area?

Preview: Riddle: It does exist. But it will never return. What is it? Americans value time and save it carefully. Time is a real, precious resource to them so every minute must count. Visitors may think Americans are always in rush and under pressure. Smiles and short conversations, and small exchanges with strangers don't exist because Americans dislike

Unit six Section A How to Prepare for Earthquakes Warm-up questions 1. Have you ever been in an earthquake? 2. What do you think you would do first if the room started to shake? 3. How should we prepare for earthquakes?

Book two Unit nine Preview Students all over the world dream of what will happen in their future. Many hope to travel abroad where they can both use their education and earn a good salary. Large, modern countries like English and America welcome such graduates, making it easy for them to enter the count