inside it represented with beads as the four pairs of chromosomes. Outside of the nucleus there will be centrioles drawn. This is where meiosis begins and replicates the cell Spindle fibers start to form on the centrioles and chromosome pairs bind together making tetrads. Nuclear membrane starts to dissolve. Nuclear membrane will be drawn in dashed lines. The chromosomes will be homologous pairs with centromere in the center holding the chromosome together and there will be spindle fibers…
pre-existing living cells, through cell division. In cell division, this involves the supplying of identical genetic material from the parent cell, DNA and protein, to two daughter cells. It results in the daughter cells having the same number of chromosomes as the parent cell. We need cell division as it is used in reproduction of new species, growth and repair of damaged cells and tissues, and to reduce the cell size. Larger cells are insufficient, as it needs more nutrients (such as sugar and…
is no crossing over or homologous pairs in this process. There is only one division in this process and two diploid cells are formed at the end of it. It results in two daughter cells with the same number of chromosomes. Mitosis has interphase, prophase, metaphase, anaphase, and telophase. In interphase, the chromosomes have already been replicated. In interphase, chromosomes duplicate. During prophase, spindle fibers attach at each centromere. In metaphase, the chromosomes line…
the sex chromosome being incomplete and results in an ‘XO’ in the 23rd pair instead of the regular ‘XX’. This results in the birth of a female with Turner’s syndrome – resulting in a short stature, infertility, heart defects and learning disabilities. As Turner’s syndrome is due to an incomplete meiosis division, it is random and not hereditary. This affects 1 in 2000 baby girls. During regular meiosis, in interphase the DNA is replicated once, the chromosomes will find their homologous pairs…
from female parent to their male offspring. A crossover is the basis of genetic information exchange, which occurs when homologous chromosomes pair up on the basis of sequence similarity in meiosis I and chiasmata is formed between two chromatids (Hochwagen 2008). Closely…
Trisomy is a cell that has three copies of one chromosome instead of having the normal two copies. Trisomy 21 is known as the congenital disorder Down syndrome. This occurs when each cell has three copies of chromosome twenty one rather than having a pair. Commonly, Down syndrome is caused by nondisjunction. Nondisjunction is "an error in which homologous chromosomes or sister chromatids fail to separate normally during meiosis or mitosis" (Huether,McCance pp.42). Scientists have discovered…
the parent cell. Mitosis is the division of the genetic material in the nucleus which is immediately followed by cytokinesis. On the other hand, meiosis occurs in sexually reproducing organisms and this type of cell division reduces the sets of chromosomes from two to one in gametes. Both mitosis and meiosis differ, however, both processes result in daughter cells forming. In the end of mitosis, two daughter cells appear shortly after and have identical DNA like the parent cell. However, in…
via the spindle microtubules and pull in opposite directions (Nelson Education, figure 9.8, page 186). In other words, centrioles create microtubules from the centrisome that will become mitotic spindles; these spindles will become attached to chromosomes via kinetochores to produce movement during the cell cycle. 2) The cell plate and cleavage furrow describe the two different processes involved in cytokinesis (the division of cytoplasm). In animal cells, furrowing begins when the midpoint…
presence of more than two sets of chromosomes (3n, 4n, 5n, etc.) (Soltis et al., 2009) as sporophyte. Polyploids may have arisen as the result of nondisjunction during meiosis or may be generated when chromosomes are dividing properly in mitosis and meiosis, but the cytokinesis does not follow. Polyploidy can be classified into two: polysomic polyploidy (autopolyploidy) and disomic polyploidy (allopolyploidy) (Stebbins, 1951). Autopolyploidy comes from doubling of chromosome number within in…
For my project, I chose to make an illustration. In the picture I have a breast cancer ribbon, a pot of boiling water, a prokaryote, a chromosome, a pedigree, and a factory to represent human impact, a flower to represent photosynthesis, a food chain, an energy pyramid, an embryo, humans evolving, a biomolecules chart, and the phases of mitosis. I drew a breast cancer ribbon because we talked about different types of cancer. There are many factors that go into the diagnosis of cancer. A lot of…