Cell Cycle and Mitosis - General Biology 1

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Questions and Answers

What is a characteristic feature of cancer cells in terms of their growth?

They undergo apoptosis more frequently than normal cells.

They respond strictly to regulatory mechanisms.

They grow in a controlled fashion similar to normal cells.

They proliferate despite the presence of regulators and checkpoints. (correct)

Which of the following describes the role of negative regulators in the cell cycle?

They have no significant impact on cancer cell behavior.

They enhance the function of cyclins and CDKs.

They halt the cell cycle and prevent progression when necessary. (correct)

They promote cell division during all phases.

What is the purpose of internal control mechanisms in the cell cycle?

To avoid mistakes that could be inherited by daughter cells. (correct)

To increase hormone release during cell division.

To ensure errors are passed on to daughter cells.

To enable faster cell division.

What triggers the release of hormones like HGH in relation to cell growth?

The size of the cell and the death of nearby cells. Signup and view all the answers

Which of the following is NOT a characteristic of cancer cells?

Increased sensitivity to growth regulators. Signup and view all the answers

What is the primary function of the G1/S checkpoint in the cell cycle?

Ensuring cells are ready for DNA replication Signup and view all the answers

What occurs during the S Phase of interphase?

Replication of chromosomes Signup and view all the answers

In which phase of mitosis do chromosomes align at the cell's equator?

Metaphase Signup and view all the answers

What is the role of the Spindle Assembly Checkpoint (SAC)?

To block cell cycle progression when kinetochores are not properly attached Signup and view all the answers

What major event occurs during telophase in animal cells?

Formation of the cleavage furrow Signup and view all the answers

During which phase does the nuclear envelope begin to re-form?

Telophase Signup and view all the answers

What initiates or inhibits cell division based on external conditions?

External events Signup and view all the answers

What happens during Anaphase as sister chromatids separate?

Spindle fibers shorten to pull chromatids apart Signup and view all the answers

What are the primary types of cells produced via mitosis?

Somatic cells Signup and view all the answers

During which phase of the cell cycle does DNA synthesis occur?

Interphase Signup and view all the answers

Which of the following best describes the number of chromosomes in mitotic cells compared to parent cells?

Chromosome number remains the same Signup and view all the answers

What is the significance of mitosis in multicellular organisms?

It allows for growth and tissue repair Signup and view all the answers

Which term describes the two identical halves of a chromosome?

Chromatid Signup and view all the answers

What is the configuration of chromosomes before DNA synthesis as noted in the content?

2n = 6 Signup and view all the answers

In which phase of mitosis do the chromosomes align at the cell’s equatorial plate?

Metaphase Signup and view all the answers

What type of cells result from meiosis, as opposed to mitosis?

Gametes Signup and view all the answers

What is the total number of chromatids present after mitosis if the original diploid number is 6?

12 Signup and view all the answers

Which statement is true regarding the cell cycle?

The cell cycle consists of a series of events that allow cell growth and division. Signup and view all the answers

Study Notes

Cell Cycle Overview

The cell cycle consists of sequential phases leading to cell growth and division.
Key phases include Interphase (G1, S, G2) and Mitosis (Prophase, Metaphase, Anaphase, Telophase).

Phases of Interphase

G1 Phase: Growth and development; cells increase in size and synthesize proteins.
S Phase: DNA synthesis occurs; chromosomes are replicated.
G2 Phase: Cell prepares for mitosis; checks for DNA replication errors.
G0 Phase: Resting phase where the cell is metabolically active but not preparing to divide.

Phases of Mitosis

Prophase: Chromatin condenses into visible chromosomes; nuclear membrane and nucleolus disintegrate; centrioles move to opposite poles.
Metaphase: Chromosomes line up along the cell's equatorial plane; spindle fibers attach to kinetochores on sister chromatids.
Anaphase: Sister chromatids split and are pulled towards opposite poles; cell elongates.
Telophase: Nuclear envelopes reform around each set of chromosomes; chromosomes decondense back to chromatin; cytokinesis occurs, resulting in two daughter cells.

Mitosis vs. Meiosis

Mitosis produces diploid (2n) body cells; DNA content remains constant pre- and post-division.
Meiosis produces haploid (n) gametes (sperm and egg); involves two rounds of division, resulting in genetic variation.

DNA Packaging

Chromosomes consist of two sister chromatids linked at a centromere.
In humans, 46 chromosomes (23 pairs) are present in somatic cells; during mitosis, the chromosome count remains constant.

Cell Cycle Regulation

Cell division is regulated by external factors (e.g., hormone release, cell size, neighboring cell death).
Internal checkpoints ensure accurate division; key checkpoints include G1/S, G2/M, and the Metaphase spindle assembly checkpoint (SAC).

Molecule Regulators

Positive Regulators: Include cyclins and cyclin-dependent kinases (CDKs) that promote progression through the cell cycle.
Negative Regulators: Proteins such as retinoblastoma protein (Rb), p53, and p21; dysfunctional in cancer cells.

Cancer Characteristics

Clonality: Genetic changes accumulate over time in cancer cells.
Autonomy: Cancer cells can proliferate uncontrollably, ignoring regulatory mechanisms.
Anaplasia: Display abnormal morphology; often have large, irregular nuclei.
Angiogenesis: Formation of new blood vessels to supply tumors.

Conclusion

Mitosis ensures equal distribution of genetic information to daughter cells, while its regulation is crucial in maintaining cellular integrity and preventing cancerous growths.

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Description

This quiz covers the key concepts of the cell cycle, specifically focusing on the stages of mitosis as outlined in General Biology 1. Students will match illustrations to each phase, describe control points, and explain the significance of mitosis in cellular processes. Strengthen your understanding of cell division and its implications in biology.