Cell Physiology and Division

These flashcards cover key concepts from the lecture on human physiology, focusing on cell structure, cell cycle, mitosis, meiosis, genetic conditions, and mechanisms of disease.

What is the function of the nucleus in a cell?

The nucleus is the control center of the cell and contains genetic materials (DNA) that direct the cell’s activities.

What are the main parts of the nucleus?

The main parts of the nucleus are the nuclear envelope, chromatin and chromosomes, and nucleoli.

What is chromatin?

Chromatin is the granular thread-like material in the nucleus composed of DNA and histone proteins.

What is the structure of a DNA molecule?

A DNA molecule is a double helix made up of chains of nucleotide molecules.

What happens during the S phase of Interphase?

During the S phase, DNA replicates itself to prepare for cell division, resulting in two daughter cells having identical genetic material.

What is the result of one complete cell division (mitosis)?

One complete cell division results in the formation of two identical daughter cells.

What is the significance of mitosis in the cell cycle?

Mitosis is essential for growth and repair of the body as it allows a cell to divide into two identical cells.

What occurs during prophase in mitosis?

During prophase, chromatin condenses to form chromosomes, nucleoli disappear, the nuclear envelope fragments, and microtubules form mitotic spindles.

What is crossing over in meiosis?

Crossing over is the exchange of large segments of DNA between homologous chromosomes during meiosis I.

What defines aneuploidy?

Aneuploidy is an abnormal number of chromosomes, which can be classified into conditions like trisomy and monosomy.

What do gametes contain regarding chromosome numbers?

Gametes contain 23 single chromosomes (1N) and half the amount of DNA found in normal somatic cells.

What are some major diseases linked to defects in apoptosis?

Defects in apoptosis are linked to diseases such as Alzheimer disease, cancer, and autoimmune diseases.

What distinguishes benign neoplasms from malignant neoplasms?

Benign neoplasms are localized, encapsulated, and grow slowly, whereas malignant neoplasms grow rapidly, invade surrounding tissues, and can metastasize.

What are oncogenes?

Oncogenes are mutated forms of proto-oncogenes that lead to deregulated cell division and can contribute to cancer.