Definition of ovum The ovum (or egg cell, figure 1) is the mammalian female gamete (haploid cell), produced in the ovary through a process called oogenesis. This cell is characterized by being a giant cell that contains most of the constituents necessary to give rise to a new organism. Development of the ovum At the […]

Population Genetics definition Population Genetics refers to the branch of Genetics that studies the genetic constituent of a population. It focuses specifically on hereditary alterations that occur in a population, in time and space. And tries to develop an evolutionary theory that explains and predicts such changes. Objectives of Population Genetics Population Genetics is responsible […]

Concept of Prophase The term prophase designates one of the subphases of mitosis, characterized by the reorganization of the cytoskeleton, migration of centriole to opposite cell poles, the appearance of the mitotic spindle, condensation of chromosomes, fragmentation of nuclear envelope and disappearance of the nucleolus. Cell Cycle The cell cycle is the basis of all […]

Proteasome Concept The term Proteasome refers to a protein complex present in the cell cytosol that has proteolytic activity. It is in this complex where proteins are degraded. Cell and Proteasome During its life cycle, the cell needs to express innumerable proteins, since they are responsible for its most varied mechanisms and functions. Proteins are synthesized […]

Quantitative Genetics definition Quantitative Genetics refers to the branch of Genetics that studies variation of a given quantitative characteristic in a given population. Quantitative Characteristics There are two types of characteristics in natural populations, those that have a continuous distribution and those that are distributed by classes. Being the most common the characteristics with continuous […]

Ribosome concept The term Ribosome refers to large complexes composed of rRNA and proteins, present in the cell’s cytosol, where protein synthesis occurs. From DNA to Protein For its processes of growth and metabolism, the cell needs proteins. For this, this same cell makes use of the transcription to read the information stored and contained in […]

Southern Blot Concept Southern blot refers to a Molecular Biology technique through which it is possible to verify whether a specific DNA sequence (gene of interest) is present in the sample. The sample under analysis contains a complex mixture (entire genome of an organism). With this technique it is also possible to obtain information on the […]

Splicing Concept The term Splicing refers to the process by which the pre-mRNA is processed to generate mRNA. This process is based on the introns removal and the linking of the exons present in a sequence. The genes in the cell In its DNA, the cell contains coding regions (exons) and non-coding regions (introns) that […]

Tissue concept The term tissue designates a set of cells having essentially the same structure and function. Tissues juxtapose, interpenetrate, and combine to form organs.   Tissue formation All cells originate in the embryo and differentiate themselves through several cellular processes to form a tissue. These cellular processes are: direction and number of cell divisions, […]

X Chromosome Inactivation definition Mammalian females are characterized by having two X chromosomes, unlike males having only one. Thus, if all genes on both X chromosomes were expressed and produce products, females would have twice as much protein as males have, which would have fatal consequences for females. However, this event is avoided by a […]