The given question says that a student has constructed a model of cellular transport using fences and several gates.
This model can be used to demonstrate the cellular transport.
The gates of the fences can be supposed as the protein pumps and the other fence demonstrates the lipid bilayer.
Let’s suppose in the fence, there are many cattles, and outside, there are less cattles, but the student open the gate and bring more cattles inside the fence. In this case, the transport of the cattles is similar to the active transport of the molecules using protein pumps. At cellular level, the energy for the active transport is provided by ATP molecules.
Now, let’s say, the student wants to feed the cattles with some nutrition rich food, which can help in maintaining the health of the cattles. The student fills his car with the cattle food and he enters inside the fence through gates. In this case, the food was not present in the fence, but was abundant in the outside environment, so, the diffusion would occur. But food cannot come self, without help of others, so, the movement is facilitated by the car, as it is done by the carrier proteins. Hence, it is an example of facilitated diffusion.
Answer:
A and B are the answers.
Explanation:
Believe me I took a test a while ago with this question
The brownish-red powder on iron is called rust. It is formed by the reaction of iron and oxygen in the presence of water or air moisture. It is called oxidizing or rusting due to exposure to water and air.
The reactants are oxygen and iron the products are carbon dioxide and water and the process is oxidization.
Answer:
2 chromosomes
Explanation:
The cell of an eukaryotic organism like roundworm contains the Nucleus, which harbors the genetic material embedded in the chromosome. The number of chromosomes of that organism is contained in each cell.
Somatic cells, also called body cells, are all other cells asides sperm and eggs, that form the tissues and organs of an organism. Somatic cells are usually diploid i.e two sets of chromosomes from each parent. In this question, the roundworm has 4 chromosomes in its somatic cell.
The reproductive cells or sex cells (sperm and eggs) of an organism always result from meiotic division of specialized cells.
Since meiosis is a kind of division that results in cells with their chromosome number reduced by half (haploid), it therefore means that the ovum and sperm cell will be expected to contain 2 chromosomes each.
This way, when fertilization occurs (sperm and egg fusion), the resulting zygote, which will eventually develop into an adult organism, will have 4 chromosomes.
