Academic Integrity and Behavior Rules

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Questions and Answers

What is mitosis in the context of cell biology?

A type of cell division where the nucleus is not divided

A part of the cell cycle where the cell grows

A type of cell division that results in four daughter cells

A part of the cell cycle where DNA is replicated (correct)

What is the function of the G1 phase in the cell cycle?

Cell death and removal

DNA replication

Cell division and the formation of daughter cells

Cell growth and preparation for cell division (correct)

What is the term for the type of DNA synthesis that occurs during the S phase?

Regressive

Liberal

Semiconservative (correct)

Conservative

What is the function of chromosomes in humans?

To transmit genetic information from one cell to another Signup and view all the answers

What is the total number of chromosomes in a female with Turner Syndrome?

45 Signup and view all the answers

What is the location of the gene referred to by the cytogenetic coordinates 15q21.1?

Chromosome 15, long arm, region 21.1 Signup and view all the answers

What is the result of meiosis in terms of the number of chromatids in the resulting cells?

Haploid cells with chromosomes in the form of one chromatid Signup and view all the answers

What is the purpose of recombination between homologous chromosomes during meiosis?

To ensure different genetic information in gametes Signup and view all the answers

What is the concept of independent genes?

Genes located on different chromosomes Signup and view all the answers

What is the frequency of recombination between linked loci?

Lower when the genes are closer together Signup and view all the answers

What is the number of meiotic products obtained from female meiosis?

1 Signup and view all the answers

During which phase of the cell cycle are chromosomes visible with a structure of two chromatids and condensed?

Metaphase Signup and view all the answers

What is the purpose of karyotyping in genetic diagnosis?

To determine the number and morphology of chromosomes Signup and view all the answers

What is the total number of chromosomes in the somatic cells of humans?

46 Signup and view all the answers

What is the term for the set of chromosomes of a species, ordered by size?

Karyotype Signup and view all the answers

During which phase of mitosis are chromosomes arranged in the equatorial plate?

Metaphase Signup and view all the answers

What is the term for chromosomes classified based on the position of the centromere?

Metacentric Signup and view all the answers

What is the purpose of arresting cell division in metaphase during karyotyping?

To observe chromosomes with a structure of two chromatids and condensed Signup and view all the answers

What is the chromosomal formula for a human female?

2n=46, XX Signup and view all the answers

Study Notes

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.