Answer:
The longest strand of DNA is the one that has descended the least in the electrophoresis gel. In other words, it is the one at the top of the gel.
Explanation:
Electrophoresis is a process that separates DNA according to its size and charge. The scientist puts the DNA samples into the indents at the top of a special gel. Then the person places it in a box that contains an ionic solution, a positive electrode at the bottom, and a negative electrode at the top. As the DNA has a negative charge, it will descend through the gel's pores towards the positive electrode. Since there are DNA of different lengths, the shortest goes down quickly through the gel than the large strands. As a result, the short strands of DNA will be at the bottom of the gel, the medium size strands will be in the middle of the gel, and the l<u>arge strands on the top of the gel</u>.
The correct answer is B. Thymus gland: enables immature lymphocytes to mature into T cells
Answer:
The atmosphere can be divided into layers based on its temperature, as shown in the figure below. These layers are the troposphere, the stratosphere, the mesosphere and the thermosphere. A further region, beginning about 500 km above the Earth's surface, is called the exosphere.
The red line on the figure below shows how temperature varies with height (the temperature scale is given along the bottom of the diagram). The scale on the right shows the pressure. For example, at a height of 50 km, the pressure is only about one thousandth of the pressure at the ground.
I think its D but I'm not sure