Mitosis is divided into phases.

a phase of mitosis is shown. the chromatids separate from each other and are being pulled to the opposite ends of the cell.

which phase of mitosis is shown in the diagram?
anaphase
metaphase
telophase
prophase

The diagram is not shown in the question. But in the question, it is mentioned that a phase of mitosis is shown, and in that phase, the chromatids separate from each other and are being pulled to the opposite ends of the cell. From this explanation, the phase of mitosis is anaphase.

Explanation:

Mitosis is a type of cell division in which a cell is replicated into exact copies of itself and duplicates all of its contents including the chromosomes and splits to form two identical daughter cells. During cell division, cells pass through different phases called cell cycle.

During interphase of the cell cycle, which occurs prior to mitosis, there are 3 phases: G1, S, and G2. In the G phases , the organelles are duplicated and the cell grows in size while in the S phase, a duplicate copy of each chromosome is synthesized (DNA replication). After the DNA and organelles are replicated during interphase , the mitosis begins. The first step is prophase where the nuclear envelope surrounding the DNA and the nucleolus disappear and the DNA condenses into chromosomes. During metaphase, the chromosomes lined in the middle of the cell. In anaphase , the chromosomes get separated and move towards opposite sides of the cell. As mitosis proceeds to telophase, the cell forms two nuclear membranes around each set of chromosomes and the chromosomes uncoil. The cell cytoplasm separates, the cell walls then pinch off and split down the middle producing two new daughter cells by a process called cytokinesis or cell cleavage.  Cytokinesis takes place during anaphase and telophase.

it is a learned trait

explanation:

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.