Cell Division Research Paper

[pic] |[pic] |1.3.5 Practice: DNA and Heredity

Cell division may happen by either mitosis or meiosis, depending on what type of cell is invovled. Mitosis is a process by which a cell divides to form two daughter cells. They each have the same exact number and kind of chromosomes as the parent cell. Meiosis occurs in the primary sex cells leading to the formation of viable egg and sperm cells. They reduce the number of chromosomes to half in each gamete so that when they are getting furtilized, the species chromosome number is kept even.

A) Meiosis consists of two cell divisions and is broken up into Meiosis I and Meiosis II. At the beginning of the Cell Cycle, in this case there are four chromatids each from the homologous pairs being A, a, B, b. This is the Diploid number (4) meaning it is 2 times the haploid number that will be seen at the end of meiosis II. During the S phase of interphase, the chromatids replicate and reach the end of G2 phase. Now starting meiosis, during the first stage of prophase I the chromosomes condense and pair up through synapsis with their sister chromatids creating AA, aa, BB, bb. After they pair up they go through a process called crossing over, where the homologous chromosomes share a piece of their genetic material with each other. Crossing over allows for the genetic diversity of chromosomes. Now there are four homologous chromosomes Aa, Aa, Bb, Bb, each containing heterozygous alleles because the sister chromatids exchanged genetic information with their homologous pair. During late prophase I, spindle fibers being to form where they will later attach to a homologous chromosomes centromere. The next stage is Metaphase I. During metaphase I, the homologous pairs line up at the metaphase plate, also known to be the center of the cell. The homologous pairs form a tetrad which is considered a group of four homologous chromosomes. These homologous chromosomes orient themselves randomly, which is know as the process of independent

Background in biology- All living organisms have something called a ‘‘genome’. Genomes contain all of the DNA within that certain organism.The identity of an organism is defined by the DNA that is present in its genome. Humans are what is known as diploid organisms. The sperm from the dad have one set of chromosomes, and the egg in the mom has the

In meiosis the pairs of chromosomes (that code for possible outcomes of characteristics) temporarily join and exchange information (crossing over) creating different combinations of gene types (alleles). For example; a pair of chromosomes could be a dominant allele (gene type) and a recessive allele which might code for brown hair. After crossing over it might be recessive which could be blond hair.

Bio 115 Exam 1 Study Guide These topics will be on the exam. ▪ What are the tenets of cell theory? • Cells are the basic structural and physiological units of all living organisms.

“Describe the role of genes and hormones in gender development” Biological sex is determined by chromosomes in your genes. At prenatal development, only a few weeks after conception, there is no notable difference between male and female structure until the Gonadal Ridges, the structure which develops either female or male sex

Each cell contains the genetic coding that makes organisms function. A collection of similar functioning cells form tissues. Groups of tissues form organs, organs make systems and all of this together is the human body. Cells store DNA, which are the blueprints of the body. Humans have 46 chromosomes that come from parents; they create the genetic coding

Chapter 8 The Cellular Basis of Reproduction and Inheritance Multiple-Choice Questions 1) The creation of offspring carrying genetic information from a single parent is called A) asexual reproduction. B) sexual reproduction. C) a life cycle. D) regeneration. E) spontaneous generation. Answer: A 2) Which of the following statements regarding sexual and asexual reproduction is true? A) Cell division only occurs after sexual reproduction. B) Only offspring from asexual reproduction inherit traits from two parents. C) Sexual reproduction typically includes the development of unfertilized eggs. D) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction. E) Only asexual

Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes move together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.

Usually women have two X chromosomes while men have one X chromosome and one Y chromosome. There are some cases where babies do not have any of these arrangements mentioned above (Through the Wormhole video). As people study these kind of cases, they have realized that there might be more than two sexes. For example, I learned that some women can be born with “Swyer syndrome”, which makes them anatomically and physiologically a female but they never achieve female sexual maturity (The Gene: An Intimate History). When their cells were examined, they discovered that they had XY chromosomes in their cells. Basically, they were chromosomally male but anatomically, physiologically, and psychologically female (The Gene: An Intimate History). Goodfellow discovered the SRY gene. This gene was the determinant of maleness but it was flicked off on women with Swyer

Discovering Mitosis (its not just a phase you going through) Mitosis tried its best to break me. All the phases to remember and all the functions of the phases seriously couldn’t the human body be a little easier to comprehend. At first glance Mitosis seemed not so complicated until realising the intricacies of the process. I grasped the basic principle of mitosis in its simplest form, cells divide. The four phases prophase, metaphase, anaphase and telophase all had a part to play in cell division but what each phase contributed I could not understand. also over the whole cell cycle there was really a total of nine phases if you count the interphase, mitotic phase, G1 phase, G2 phase and S phase I needed some clarification. I endeavoured to find out answers to four questions to clarify and understand clearly.

The human body is the miracle of miracles. A single cell meeting another single cell creating the most impacting species known to the world. However, how does the human body work? How can two cells create something to change the world? Do the cells change us? What is part of our nature?

Meiosis I had 6 steps: Interphase, Prophase I, Metaphase I, Anaphase I, Telophase, and Cytokinesis. In Interphase, the cell grows, repairs, performs its usual functions, and replicates DNA. During Prophase I, each replicated chromosome pairs with its corresponding homologous chromosome forming a tetrad. During tetrad formation, sections of chromosomes can be exchanged between chromatids, a process called crossing over. In Metaphase I, paired homologous chromosomes line up across the middle of the cell. During Anaphase I, Spindle fibers pull each homologous pair toward opposite ends of the cell. In Telophase I, a nuclear membrane forms around each cluster of chromosomes. Cytoplasm then occurs resulting in two new daughter cells. The daughter cells contain chromosome sets that are different from each other and the parent

The cell cycle Chapter review Cell division creates duplicate offspring in unicellular organisms & provides for growth, development , & repair in multicellular organisms The cell cycle extends from the creation of a new cell by the division of its parent cell to its own division into 2 cells 12.1 Cell division results in