【单选题】A new study indicates that basic steps taken by people daily can go a long way in ____ the greenhouse gas emission.
【多选题】The basic pathway for repairing damage to DNA involves three basic steps:
A.
Step 1: excision: the damaged DNA is recognized and removed by one of a variety of mechanisms. These involve nucleases, which cleave the covalent bonds that join the damaged nucleotides to the rest of the DNA strand, leaving a small gap on one strand of the DNA double helix in the region.
B.
Step 2: resynthesis: a repair DNA polymerase binds to the 3ʹ-hydroxyl end of the cut DNA strand. It then fills in the gap by making a complementary copy of the information stored in the undamaged strand.
C.
Step 3: ligation: when the repair DNA polymerase has filled in the gap, a break remains in the sugar–phosphate backbone of the repaired strand. This nick in the helix is sealed by DNA ligase, the same enzyme that joins the Okazaki fragments during replication of the lagging DNA strand.
【单选题】零件有上、下,左、右,前、后六个方位,在俯视图上能反映零件的( )方位。
【简答题】零件有上、下、左、右、前、后六个方位,在主视图上只能反映零件的 方位,俯视图上只能反映零件的 方位。
【简答题】An international contract should be executed through four basic steps: pre-preparation for contract, contract negotiation, 1 and contract execution, and each steps includes detail procedures, an inter...
【判断题】云计算的核心就是以虚拟化的方式提供各种服务,而物联网的应用本身就是以“云”的方式存在的,从这个意义上说,物联网需要借助于云计算技术解决大量的问题,是云计算在现实中的一种应用形式。( )
【单选题】What is NOT one of the three steps basic steps of CRISPR?
B.
Production of CRISPR RNA