... and freshwater protists. Subclass Pelobiontae includes one genus, Pelomyxa, large cells which lack almost every characteristic of eukaryotic cells except the existence of a membrane-bound nucleus; these cells' nuclei divide like bacterial nucleoids. Members of the Mastigamoeba subclass are unicellular, asexual heterotrophs that may be either parasitic or free-living. Class Metamonada consists of unicellular organisms ... cilia have the same ultrastructure but are modified to perform various functions. There are two types of ciliate nuclei, but only the micronuclei divide by mitosis. The ...

• Word Count: 3806
• Approx Pages: 15
• Grade Level: Undergraduate

... contains chromatin, a condensed complex of DNA and protein which make up chromosomes. DNA carries the instructions for cell division and also controls cell growth. Outside of the nucleus is what is referred to as the cytoplasm, a jelly like substance which fills the inner space of the cell between the outer membrane and the nucleic membrane. Within the cytoplasm ... DNA as their genetic material, they are both membrane bound and both have ribosomes. However prokaryotic cells such as bacteria are smaller and much more simply structured (Fig 3) They lack a nucleus and therefore have no c...

• Word Count: 1603
• Approx Pages: 6
• Has Bibliography
• Grade Level: Undergraduate

... , as the name suggests, the triplication of the 21st chromosome. Genes which, basically, contain the blueprints for our cellular structure, are grouped along rod-like structures called chromosomes. Normally, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. In Down syndrome (DS), however, the cells usually contain not 46, but 47 chromosomes ... gene (alleles) may be present. (Example: the genetic information for eye color is a "gene;" the variations for blue, green, etc. are the alleles.) Human cells divide in two ways, the first bei...

• Word Count: 3980
• Approx Pages: 16
• Has Bibliography
• Grade Level: Undergraduate