Exploring Cells and Necessity of Specialized Cells and Tissues

Table 1: An illustration of the surface area to volume of cubes of varying sizes

Q.1 To meet AC1.3 you need to explain how all the 3 systems work together. Put full references in a list at the end of your assignment. In text you should just use e.g. (Hull et al. Nd).

Table 1: An illustration of the surface area to volume of cubes of varying sizes.

1. a. Study the information in Table 1. Calculate the surface area to volume ratio for each cube, and use it to explain why large organisms need to have many microscopic cells, rather than fewer larger cells (100 words) (AC 2.1)

b. 3:1, 3:2, (1.5:1)  1:1, 3:4 (0.75:1)

Express ratios as a number : 1

Q2.a. For cellular respiration, all organisms require oxygen. An organism's requirement for oxygen is proportional to its volume. The rate of O2 absorption from the environment is related to the surface area of the environment. The surface area-to-volume ratio of the smaller cube is 3:1, whereas the larger cube is just 3:4. This shows that the surface area-to-volume ratio of larger organisms decreases. Larger cells will absorb oxygen slower, whereas smaller cells can absorb oxygen much faster.

b. Explain why organisms need specialised cells and tissues in order to survive (150 words) (AC 2.1)

Tissues are formed when specialised cells gather together the kind of cell determines the type of tissue. Tissues also evolve to perform specialised roles within the body. Tissue comes in a variety of shapes and sizes. These are some of them:

-epithelial tissue – this forms the lining and covering of skin

-connective tissue – help joins other tissues together

-muscle tissue – help to contracts and can produce movement

-nervous tissue – help to receive stimuli and conveys impulses

-membranes – help in covering, lining, dividing, anchoring. (Connor 2006).

Q3 Cells everywhere! There are millions of cells in the body. If they were all the same, we would still look like a blob of jelly! Cells have many different shapes and sizes, and each has adapted to do a specific job in the body.

-The sperm cell, ovum, neuron, and epithelial cell of the ileum are examples of specialised cells.

-Epithelium cell: is a lining tissue that offers smooth surfaces to bodily areas and organs such as the skin, respiratory tract, blood vessel interiors, and body cavities.

-Neuron: These are the nervous system's foundational tissues. They are highly specialised nerve cells that carry information.    

-Sperm cell: The male reproductive cell which contains 23 chromosomes.

-Ovum: The female reproductive cell which contains 23 chromosomes. (Connor,2006)

Q4. Everything in the human body is made of only FOUR BASIC kinds of tissue: nervous, muscular, epithelial, and connective tissue. Research and answer the following questions.

 a.        b.    

 Q5. Stem cells: grow your own organs. Stem cells have been a controversial topic in the news over the last 20 years. The properties of stem cells make them an ideal solution to replenishing damaged cells in the body, especially in the brain as neurones cannot regenerate under normal circumstances.

The essay should consider the following:

-A description of the key features of stem cells when compared to the features of specialised cell. Make sure you refer to the following key words: Multipotent, pluripotent, totipotent, and relate these to specific examples.

-Somatic cells, such as human stem cells, are largely unspecialized. They can divide to create stem cells and cells that can develop into numerous cell types. Embryonic stem cells are pluripotent in early embryos, meaning they can develop into any cell type that makes up the individual.