Gene differences are so important among the population because they the distinctivnes of people
Answer: The answers seem correct.
1. Active transport - the process in which energy is used to move the particles of a substance against a concentration gradient from a region where they are in lower concentration to a region whey are in higher concentration.
2. The answer chosen for #2 makes sense because energy is usually needed when you putting effort into doing an activity that includes some type of force. That means ions are using energy to be moved against the concentration gradient.
3. Volume makes sense for the last question since the cells are using a space (volume) to move material in and out by diffusion. The other options besides volume are unreasonable.
There are man chemical and physical changes such as geno and pheno.
Answer:
Structure. The IVC is formed by the joining of the left and right common iliac veins and brings collected blood into the right atrium of the heart. It also joins with the azygos vein (which runs on the right side of the vertebral column) and venous plexuses next to the spinal cord.
Source: common iliac vein; lumbar veins;
The double membrane. It's theorized that chloroplasts used to be their own single-celled organism in the environment (and therefore with its own membrane). Then, the theory states, a larger cell took in the chloroplast by endocytosis, which involves surrounding the chloroplast in the large cell's own membrane. The chloroplast would then have two membranes surrounding it. This is similar to the thinking for mitochondria becoming an organelle as well. Hope this helps! :)