Meiosis

Introduction to Cell Biology – Unit 10193 – Chloe Barrett This essay discusses the difference in prokaryotic and eukaryotic cells, two types of specialised eukaryotic cell, and the relation of the structure of cell membranes to their function of moving substances in and out of cells. Prokaryotic and Eukaryotic cells are two very different, but also very similar cells. There are many differences between them that can help to associate between each one. Eukaryotes are any organism that…

years has been solely based on the randomized process of genetic inheritance from one generation to the next generation. Instead of duplicating their genetic information and create identical offspring, humans produce sex cells, through the process of meiosis, that carry only half of the genetic information, and fertilize them in order to produce non-identical offspring (Science Learning Hub, 2011). The ability to create unique offspring for every –sexual reproduction- allow a greater chance of…

Gene mutation is a permanent alteration in the DNA nucleotide sequence, such that the sequence is different from what is commonly found. Mutations range in size; they can affect anywhere from a single base pair, to a large segment of a chromosome. Gene mutations can be categorized in two major ways, hereditary and acquired or somatic mutation. Hereditary mutations are mutations inherited from a parent. These mutations are present in virtually every cell of the body, and are present throughout…

It is not known exactly what causes breast cancer, however “It is estimated that in 2015 there will be 231,840 new cases of invasive breast cancer, 62,290 new cases of carcinoma in situ (CIS) of the breast will be found (CIS is non-invasive and is the earliest form of breast cancer), and about 40,290 deaths from breast cancer.” (The American Cancer Society 2014, September 9). Other than skin cancer and second only to lung cancer, breast cancer is the leading death among women in the United…

‘Implicature is a component of speaker meaning that constitutes an aspect of what is meant in a speaker’s utterance without being part of what is said’ (Horn 2006: 3). Broadly speaking, what speaker intends to say is definitely richer than what he directly expresses. This term means the literal sense and non-literal sense of utterance (Horn 2006: 3). Herbert Paul Grice focused on what is said, what particular words mean, what the speaker wants to convey, what the speaker really conveys. Korta…

onto the offspring and make the offspring more favourable in the population (Bailey, 2017). Genetic variation occurs in a population through DNA mutation and sexual reproduction (Bailey, 2017). Genetic recombination occurs through the process of meiosis which produces combinations on a single chromosome (Bailey,…

Randomness and chance are also involved in genetic variation, and both harmful and beneficial mutation. Genetic variation contributes to the diversity of genes in a population.11 For example, eye colour, skin colour, ear shape, hair colour all vary differently in humans.11 The Hardy-Weinberg Principle is a method for geneticists to study genetic variation and evolution. It is a model that predicts the outcome and offspring of a non-evolving population. This model is then compared to an existing…

Interruptions in the Cell Cycle The cell cycle is the process of which a somatic or gametic cell reproduces DNA and splits into two or four different cells, respectively. This process contains multiple stages such as G1, S, G2, Mitosis or Meiosis, and Cytokinesis. Throughout this procedure, many errors can occur and be harmful to the organism. To prevent these mistakes from becoming a problem, the cell cycle contains many checkpoints and regulators (Lodish). A checkpoint is where “stop and…

Even though systematics previously used more conventional systems such as Chatton’s division of life in to two main cellular groups; the eukaryote-prokaryote dichonomy (cited in Sapp, 2005), as well as Whittaker’s Five Kingdom system to organise all living things (Whittaker, 1969), they do not co-exist compatibly or correctly. The five kingdom system is not phylogenetically correct and eukaryote and prokaryote systems do not take into consideration new sequencing abilities (Kandler, Wheelis &…

tasks and functions. Without cells all organisms would cease to exist. Like all living things, the cell must also reproduce and eventually die. Cells reproduce through a series of division called mitosis, and also through a nuclear division called meiosis which produces two separate cells that only contain half of the genes found in the mother cell. Within the body most cells use mitosis to divide and reproduce.…