Trisomy 21

Last week I wrote about the function of the DNA in our cells. Today I will write about a genetic condition that is known around the world. This condition is Trisomy 21 usually known Down syndrome. This is because there is a genetic disorder caused by an abnormal amount of autosomal chromosomes: 2N + 1. The syndrome has three autosomal chromosomes 21 instead of two, 2N +1= 46 +1= 47. Down syndrome include low muscle tone, small mouth, people who suffer this syndrome, keep it open, because they do not have enough space for the tongue, peculiar eyelids, heart defects, mental retardation, and poor resistance to infection. In addition, 1 of 700 children born with the syndrome.

Although we know how Down syndrome occurs. Down syndrome occurs at conception, across all social groups and to parents of all ages. The trend of Down Syndrome increases with maternal age. After 35 years there is a dramatic increase in the possibility of having children with this syndrome. It is nobody's fault. There is no cure and it does not go away. Finally, this video https://www.youtube.com/watch?v=m2r4Y3rvnwo show to you a young man who has Down syndrome but this is not an impediment for him to succeed in life.

Some sentences that were presented here were obtained from http://www.downsyndrome.org.au/what_is_down_syndrome.html

Deoxyribonucleic acid (DNA)

Each chromosome has one long DNA molecule with hundreds or thousands of genes. Genes encode information for building proteins. DNA is inherited by offspring from their parents and controls the development and maintenance of organisms. Deoxyribonucleic acid (DNA) is the hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA. Most DNA is located in the cell nucleus, but small amount of DNA can also be found in the mitochondria.

Each DNA molecule is made up two long chains arranged in a double helix. Furthemore, each link of a chain is one of four kinds of chemical building blocks called nucleotides. These chemical building blocksor chemical bases are adenine (A), guanine (G), cytosine (G), and thymine (T). The chemical bases pair up with each other, adenine with thymine and cytosine with guanine to form bases pairs. The human DNA consists of about three billion bases. The bases are also attached to a sugar molecule and a phosphate molecule. The sugar and phosphate when are together they forms a nucleotide. By last, DNA can be replicate,  each strand of DNA in the double helix can serve as pattern for duplicating the sequence of bases, and when cells divide each new cell needs to have an exact copy of the DNA from the old cell.

Most of this information is from https://ghr.nlm.nih.gov/handbook/basics/dna 

Cell Reproduction

This week I will be writing about the process that the cell performs to reproduce, this process is called cell division. First of all, I want that you know what are a cells. The cells are the basic building blocks of alla living things. The human body is composed of trillions of cells. They provide structure the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body's hereditary material and can make copies of themselves. Cells have many parts, each with a different function. Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. Human cells contain the following major parts cytoplasm, cytoskeleton, endoplasmic reticulum, Golgi apparatus, lysosomes and peroxisomes, mitochondria, nucleus, plasma membrane and ribosomes. 

You may be wondering what is the cell division. Cell division involves the distribution of identical genetic material, DNA, to two daughters cells. What is most remarkable is the fidelity with the DNA is passed along, without dilution or error, from one generation to the next. The cells have the process of mitosis and meiosis to perform cell division. Mitosis is a form of eukaryotic cell division that produces two identical daughter cells with same genetic component as the parent cell. Chromosomes replicated during the S phase are divided in such a way as to ensure that each daughter cell receives a copy of every chromosome. In actively dividing animal cells, the whole process takes about one hour. Mitosis involves six phases that are Prophase, Prometaphase, Metaphase, Anaphase, Telophase, and Cytokinesis.

Nevertheless, Meosis is the form of eukaryotic cell division that produces haploid sex cells or gametes (which contain a single copy of each chromosome) from diploid cells (which contain two copies of each chromosome). The process takes the form of one DNA replication followed by two succesive nuclear and cellular divisions (Meiosis I and Meiosis II). As in mitosis, meiosis is preceded by a process of DNA replication that converts each chromosome into two sister chromatids. As you read, Meiosis have two succesive nuclear and cellular divisions. Meiosis I and Meoisis II consist of six phases, as Mitosis. On Meiosis I are Prophase I , Prometaphase I, Metaphase I, Anaphase I, Telophase I, and Cytokinesis. Too, on Meiosis II are Prophase II , Prometaphase II, Metaphase II, Anaphase II, Telophase II, and Cytokinesis.

In this link, http://www2.le.ac.uk/departments/genetics/vgec/schoolscolleges/topics/cellcycle-mitosis-meiosis, you can encounter the definition of all phases are in each process. Finally, I want that you see three videos that I posted below. This videos explain to you in a graphic form the process of the cells and it can improve your knowledge.

This two videos show to you the process of Mitosis:

1. https://www.youtube.com/watch?v=DwAFZb8juMQ&list=PL7BpecGDIhhoBM8wazP45ky__HQrOE5IC&index=2
2. https://www.youtube.com/watch?v=C6hn3sA0ip0

This video show to you the process of Meiosis:

1.  https://www.youtube.com/watch?v=nMEyeKQClqI

     
 Bibliography:                    

• Cell definition: https://ghr.nlm.nih.gov/handbook/basics/cell
• Cell division definition: http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect16.htm
• Mitosis and Meiosis definition: http://www2.le.ac.uk/departments/genetics/vgec/schoolscolleges/topics/cellcycle-mitosis-meiosis

Biology and its branches

Hi, today I will go to write about what is biology and what are the branches in which it develop and the meaning of each branch. Biology is the science that studies living organisms. In the field of biology we study various organisms which are classified within the branch of it. These branches are as follow Cellular Biology or Cytology, Molecular Biology, Developmental Biology, Marine Biology, Physiology, Genetics, Zoology, Botany, Ecology and Microbiology. Now, like I wrote before, I will go to write the meaning of each branch. Too, I will divide the meanings of each biology in two sections.

The Cellular Biology or Cytology is the branch that studies the structure and function of cells. It is responsible for understanding the properties, structures, functions and the interaction with the environment of cells. The another branch is Molecular Biology. Molecular Biology is the area of Biology that studies the biological processes on a molecular level. It focuses on studying the interactions of different cell systems. The next, is Developmental biology, this studies the development of living organisms from birth until death. This biology is focuses on the genetic control of cell growth and cell differentiation and morphogenesis. The fourth biology is Marine Biology. Is the branch that is responsible of study all the creatures that live within the marine environment. The last one of this section is Physiology, that is the study of the functions of living beings and is the branch that study the respiratory, reproductive, nervous system, among other systems.

The second section begins with the biology that study biological heritage which is transmitted from generation to generation and is centered in the study of genes formed by segments of DNA and RNA, this biology is Genetics. The second is Zoology. Is the branch that is responsible for study of animal life. Also, we biologists study the plants. The biology that study the plants is botany, through it we can classify, describe, identify and learn about reproduction, morphology or phisiology of the natural beings of the plant world. Furthermore, another science of biology is Ecology that studies the relationship of living beings on the planet with their natural habitat. By last, Microbiology is the study of microorganims, which are the smallest living things like bacteria and fungi.

The most information that you saw above is from http://education.onehowto.com/article/what-are-the-main-branches-of-biology-and-their-definition-1598.html