Cell Continuity and Division Flashcards
(24 cards)
What is cell continuity?
The ability of cells to divide and survive from one generation to the next.
Cell continuity is essential for growth, repair, and reproduction in organisms.
Define a chromosome.
A thread-like structure, found in the nucleus, containing DNA and protein.
Chromosomes are crucial for the storage and transmission of genetic information.
What is a diploid cell?
A cell with two copies of each chromosome (2n), e.g., human somatic cell.
Diploid cells are the typical state for most body cells in multicellular organisms.
What is a haploid cell?
A cell that contains one copy of each chromosome (n), e.g., human gamete.
Haploid cells are involved in sexual reproduction.
What is interphase?
The stage in the cell cycle during which cells are not dividing.
Interphase includes cell growth, replication of organelles, and DNA replication.
Define mitosis.
The division of a nucleus into two genetically identical daughter cells with the same number of chromosomes.
Mitosis is crucial for growth and repair in multicellular organisms.
What are the four stages of mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
Each stage has distinct processes that ensure proper chromosome segregation.
What occurs during prophase?
Chromatin shortens, individual chromosomes become visible, the nucleolus disappears, and spindle fibers start to form.
This is the first stage of mitosis.
What occurs during metaphase?
Chromosomes line up along the equator, and spindle fibers attach to the centromeres.
Metaphase ensures that chromosomes are properly aligned for separation.
What occurs during anaphase?
Spindle fibers contract, chromosomes split at the centromere, and sister chromatids are pulled to opposite poles.
This stage ensures that each daughter cell receives an identical set of chromosomes.
What occurs during telophase?
Chromosomes elongate, reverting to chromatin, and nuclear membranes reappear.
Telophase marks the near end of mitosis.
What is cytokinesis?
The process where the cell splits into two.
In animal cells, a cleavage furrow forms; in plant cells, a cell plate forms.
What is the primary function of mitosis in multicellular organisms?
For growth and repair.
Mitosis allows for the replacement of dead or damaged cells.
What is the primary function of mitosis in single-celled organisms?
To allow organisms to reproduce, e.g., yeast and amoeba.
Mitosis facilitates asexual reproduction in these organisms.
Define meiosis.
A form of cell division in which a diploid cell divides to produce four genetically different haploid daughter cells.
Meiosis is essential for sexual reproduction.
What are the functions of meiosis?
- Gamete formation in animals (sperm and eggs)
- Maintains the diploid number
- Increases genetic variation
Meiosis allows for genetic diversity through processes like crossing over.
True or False: Mitosis results in genetically different daughter cells.
False.
Mitosis produces genetically identical daughter cells.
What is cancer?
The uncontrolled mitotic division of normal cells.
Cancer can lead to the formation of tumors, which can be benign or malignant.
What are carcinogens?
Cancer-causing agents that cause mutations in DNA.
Examples include cigarette smoke, UV radiation, and certain viruses.
Name two causes of cancer.
- Carcinogen exposure
- Genetic mutations
The risk of cancer increases with age due to the accumulation of mutations.
What is the role of a biopsy in cancer detection?
To examine a tiny sample of tissue for cancer cells.
This procedure helps in diagnosing cancer.
What are common treatments for cancer?
- Surgery
- Radiotherapy
- Chemotherapy
Treatment choice depends on cancer type, location, and patient health.
Fill in the blank: A cell is _______ (2n) when it has two copies of each chromosome.
[diploid]
Diploid cells are typical in most somatic cells.
Fill in the blank: A cell is _______ (n) when it contains one copy of each chromosome.
[haploid]
Haploid cells are essential for sexual reproduction.
