Very carefully (i'm sorry but there is not enough information provided)
Double fertilization occurs in Angiosperms
Answer;
Semi-permeability means that only certain molecules are allowed to pass through.
Explanation;
-Semi-permeability is one of the features of a cell membrane, which means that the membrane allows selective movement of materials in and out of the cell; that is only certain molecules can enter or leave the cell.
-For example smaller molecules such water and ions such as potassium and sodium ions are able to leave and enter the cell, while other molecules that are large such as protein molecules can not enter or leave the cell.
D) The Earth was hit by a one or more objects from space 65 million years ago. The iridium layer shows an extraterrestrial cause for the extinction at the Cretaceous Tertiary boundary, discovered by the Alvarez family. The first discovery of this layer was in the Bavarian alps, in Lattengebirge. The Alverez family proposed that the extinction of the dinosaurs was due to a large meteor hitting the Earth at the end of the Cretaceous period, marking the KT boundary with this clay layer which has a high content of iridium. Iridium is not common on Earth, but is common in meteors.
The main structural difference between LDL and HDL is their compositions. Approximately 50% of the weight of an LDL particle is cholesterol and only 25% is protein. High-density lipoprotein particles, on the other hand, consist of 20% percent cholesterol by weight and 50% protein.