What role does serendipity have in science? Give an example of a relevant discovery.
The discovery of cyclins and their involvement in the control of the cell cycle was based on serendipity. This means it was accidental. Many discoveries in science are based on the scientific method, but we must realize that some scientific advancements a
Explain how mitosis produces two genetically identical daughter nuclei. Include the sequence and events of the four phases of mitosis.
A single diploid cell with 46 chromosomes goes through few stages and produces two identiical diploid cells. Before Mitosis, the DNA in the nucleus must be replicated aka. the interphase during which the cellular contents other than the chromosomes duplic
What is meant by supercoiling?
Supercoiling occurs when a chromosome becomes very dense, coiled, thicker and shorter. As a result of supercoiling chromosomes are more visible in prophase phase of mitosis and meiosis.
What is the difference between cytokinesis in plants and animals?
The process of cytokinesis is defined as the division of cytoplasm to form two different daughter cells after the process of mitosis has taken place. A cell plate forms between the two cells to guide the process.Now the main difference between cytokinesis
Why is interphase considered an active phase of the cell cycle. Outline the events that happen during interphase.
Metabolic reactions such as cell respiration, DNA replication, and protein synthesis occur during Interphase. Interphase consists of three phases G1, S, and G2.
In G1phase, the numbers of mitochondria in the cytoplasm increase due to the growth and division of mitochondria. Chloroplasts increase in plant cells in the same way. Cellular contents other than chromosomes increase during this phase.
...
During S phase the cell replicates it's genetic material in the nucleus in order to end up with a complete set of genes after the cell division.
...
G2 phase follows S phase and starts to prepare the cell for mitosis/meiosis. It is a check point when the cell makes sure the components are properly duplicated.
...
Explain the role of cyclins.
Cyclins are a family of proteisn that control that progression of through the cell cycle. Agression through parts of the cell cycle are affected in vairous ways by specific cylins. In cyclin D triggers cells to move from G1 then to S phase. In cyclin E, p
Explain the relationship between mutagens, oncogenes, and metastasis.
Mutagens are agents that alter the genetic material of DNA. The formation of tumours starts with mutations in genes that is involved in the control of the cell cycle called oncogenes. Furthermore, the process where the tumours spread to different parts of
Outline the correlation between smoking and the incidence of cancer.
The correlation between smoking and the incidence of cancer is that the chemicals in the tobacco can cause mutations to happen in the body, developing tumors. The chemicals damage the cells that line the lungs. When you inhale cigarette smoke, which is fu
Explain how you would use visual cues to identify the phases of mitosis in cell viewed with a microscope or in a micrograph.
In interphase, the content of the cell is hard to differentiate, due to the duplication of chromosomes. During prophase, the chromosomes condense and become more visible. Spindles become visible in the cytoplasm. In metaphase, all the chromosomes allign a
Explain how to determine a mitotic index from a micrograph.
From a micrograph, count the number of cells undergoing mitosis. Then, count the total number of cells on the micrograph. Divide the number of cells undergoing mitosis by the total number of cells to get the mitotic index.
Explain the difference between the term chromosome and chromatid and when they should be used.
A chromosome consist of a DNA double helix bearing a linear sequence of genes. During the cell division, DNA is replicated. The resulting two identical copies of DNA are connected to each other at the centromere. Each copy is called a chromatid. Before ce