Cell division

compacted into chromosomes to fit into the nucleus. As well as storing genetic material and information in the nuclei, DNA has many different functions. One of DNA’s main functions is DNA replication, where DNA is copied in order to form two daughter cells of DNA. During DNA replication, DNA helicase causes the hydrogen bonds between the complimentary base pairs to break and the double helix to unwind into two strands. DNA polymerase then attaches to the start of each strand, acting as a…

1. Monozygotic twins-Twins resulting from one zygote that at an early stage of development separated into independently growing cell aggregations giving rise to two individuals of the same sex and identical genetic constitution. I've always heard of "identical twins" but most of my life I had never heard of the scientific term monozygotic twins. Learning the scientific word is a definite increase in my own personal knowledge. 2. Umbilical cord-A flexible cordlike structure containing blood…

caused when abnormal cell division results in extra genetic material from chromosome 21, this genetic disorder causes lifelong intellectual disability and developmental delays, and in some people it causes health problems. There are different types of Down syndrome. At first, trisomy 21 that are cause by an error in cell division, when a pair of 21st chromosomes in either the sperm of egg fails to separate. Secondly, mosaic Down syndrome when there is a mixture of two type of cells, some…

thus peptide bonds get exposed and vulnerable to pepsin. Proteins are cut up into smaller polypeptides by pepsin. The gastric juice does not destroy the stomach cells because they are activated only when they reach the lumen. HCL composes of hydrogen and chloride ions that are secreted by parietal cells. Pepsin is released by chief cells in the inactive form, pepsinogen. It is the HCL that catalyzes the chain of events of making pepsin…

key for the development and survival of a fetus/embryo. 2. Leydig cells • Leydig cells form and secrete testosterone. The testosterone is secreted in response to the lutenising hormone. Spermatozoa production is promoted by the testosterone secreted. The testosterone being secreted by the Leydig cells are important for the formation of secondary characteristics of the male. 3. The different pancreatic cells • One of the pancreatic cells is the exocrine gland. The exocrine gland secretes out…

life is now set for success. Multicellular life in great complexity can now occur. When cells would live in close proximity to each other they would eventually develop different roles that acted as a single organism. This would allow the cells to share the task of life by dividing the labor. Eventually the cells would become so dependant on each other that they would not be capable of survival as a single cell. So over time their genomes would combine resulting in an multicellular organism.…

is to regulate the level of free iron ions within cells. Transferrin transports iron from cells (such as intestinal cells and cells of the reticuloendothelial system) to all cells that are dividing within the body. The structure of transferrin enables the protein to properly transport iron throughout circulation. Transferrin has homologous carboxyl and amino domains and each of these domains bind to 1 ion of ferric iron (2). Once at the target cells, (entering via the transferrin receptor), the…

The human body contains a bunch of different systems, and it has many divisions within the systems. Organs, tissues, bones, joints, and cartilage are just a few things that are the genetic makeup of the actually human skeletal system. The human skeletal system is very diverse but unique at the same time. Bones are responsible for playing a major role in how our body is made up and functions. A bone is a rigid organ in which it contains living and evolving tissue that has various particular…

‘Immortal Life’ in cells happened in the mid-1900s following the treatment of an African American woman named Henrietta Lacks. The cells taken from her cervix were the first of human cells to grow rapidly and reproduce many generations of cells in a culture in a laboratory. A magnificent medical miracle however has a deeper and darker side to it as explored in The Immortal Life of Henrietta Lacks by Rebecca Skloot. It is a factual based account of the life of Henrietta Lacks and her HeLa cells.…

elegans as an experimental model organism and it has been used in biological fields, it played a huge role in the understanding and development in the knowledge about multicellular organisms since 1960s (8). Genetics and organ development, programmed cell death studies, and describing the mechanism of RNA interference (RNAi) led to award Noble prizes in physiology for Sydney Brenner, John Sulston and Robert Horvitz, Craig Mello, and Andrew Fire respectively.…