Answer:
1) the genes and chromosomes do not double after each generations because parental sex cells are haploid and only contain one set of chromosomes. During fertilization the two cells fuse to form a diploid zygote with two copies of genes and chromosomes. For example a normal human has 46 chromosomes (2 copies of 23 chromosomes) during reproduction gametes which contain 23 chromosomes (haploid) fuse to form an offspring with the correct number of chromosomes ( 23 + 23 = 46).
2) offspring only receive one set of chromosomes from each parent so to maintain the chromosome number of humans. If this did not happen you would not be the same species.
Answer:
d. The cell begins to elongate and the two poles have an equivalent collection of chromosomes.
Explanation:
The cell cycle is a fundamental cellular process by which a parent cell divides into two or more daughter cells. In somatic cells, this cycle can be divided into two major phases: interphase, where the cell prepares for its division, and mitosis or 'M phase'. The M phase can in turn be divided into four stages: 1-prophase (also divided into early prophase and prometaphase), 2-metaphase, 3-anaphase, and 4-telophase. During prophase, chromatin condenses, thereby forming visible chromosomes. Subsequently, during metaphase, the sister chromatids (i.e., the two identical halves of a single replicated chromosome) align along the middle of the cell at the metaphase plate by attaching their centromeres to the spindle fibers. Next, during anaphase, sister chromatids are separated and move to opposite poles of the cell, pulled by the mitotic spindle fibers. At the end of anaphase, the microtubules of the mitotic spindle pull the two sister chromatids toward opposite poles, thereby the cell gets begins to lengthen. Finally, during the telophase, daughter chromosomes arrive at opposite poles and uncoil, while daughter nuclei begin to form at the two poles and nuclear envelopes are formed.
