Academic Integrity and Behavior Rules

Rules of Behavior

• Academic Integrity is essential, and any violation, such as plagiarism or unauthorized use of information, will result in loss of continuous evaluation and potential sanctions.
• Signing the attendance sheet for a classmate who is not in class is not allowed.
• Improper use of electronic devices during exams will result in a grade of 0.0 for that call.
• The use of electronic devices is not allowed during classes, both theoretical and practical.
• The teacher reserves the right to take measures to protect Intellectual Property.

Cell Cycle and Mitosis

• DNA in humans is organized into chromosomes, which contain all the genetic information of an individual.
• Chromosomes are transmitted from one cell to another through mitosis.
• The cell cycle consists of:
  • Interphase: cell grows, collects necessary materials, replicates DNA, and distributes content equally between daughter cells.
  • Mitosis: separation of sister chromatids, migration to opposite poles, and cell division.
  • Phases of mitosis: prophase, metaphase, anaphase, and telophase.
  • The only moment of the cell cycle where chromosomes can be observed with a structure of two chromatids and condensed is in mitotic metaphase.

Chromosomes and Karyotyping

• The number and morphology of chromosomes are relevant for genetic diagnosis and are related to certain pathologies.
• Karyotyping is a technique used to observe chromosomes, which involves:
  • Obtaining a sample of cells (blood or fetal) and arresting them in metaphase.
  • The karyotype is the set of chromosomes of a species ordered by size.
• Chromosomes can be classified by their morphology based on the position of the centromere as metacentric, submetacentric, acrocentric, and telocentric.
• Humans have metacentric, submetacentric, and acrocentric chromosomes.

Chromosomal Formulas

• 2n=46, XX: the set of chromosomes of somatic cells of a female individual contains 46 chromosomes (23 pairs), with the sexual pair being XX.
• 2n=46, XY: the set of chromosomes of somatic cells of a male individual contains 46 chromosomes (23 pairs), with the sexual pair being XY.
• 2n=47, XX, +21: a female with 47 chromosomes, having an extra chromosome 21, which is a characteristic of Down syndrome.
• 2n=45, X0: a female with 45 chromosomes, missing one X, which is a characteristic of Turner syndrome.
• 15q21.1: cytogenetic coordinates of a gene, located on chromosome 15, long arm (q arm), region 21.1.

Meiosis

• Meiosis is a process by which diploid cells with chromosomes having two chromatids produce haploid cells with chromosomes in the form of one chromatid.
• It involves two cell divisions without an intermediate phase of synthesis.
• Depending on whether it is a male or female meiosis, 4 or 1 meiotic products are obtained, respectively.
• Recombination between homologous chromosomes and their random segregation occurs, resulting in no two gametes with identical genetic information.

Independent Genes and Linked Loci

• Independent genes are genes located on different chromosomes, and their alleles may segregate in all possible combinations with the same probability.
• Linked loci are genes located on the same chromosome, and their alleles will not segregate with the same probability, depending on the recombination that occurs between said genes.