Cell Division Flashcards
What is cell continuity?
All cells develop from pre-existing cells.
Define chromosomes.
Structures containing DNA and protein. Called chromatin when it is not dividing.
What is a haploid?
n chromosomes (1 set of chromosomes).
What is a diploid?
2n chromosomes (2 sets of chromosomes).
What is cancer?
Uncontrolled mitosis of cells.
What can cause cancer?
Carcinogens, e.g. cigarette smoke, some viruses, UV rays.
What are gametes?
Haploid cells that are able to fuse with another gamete of the opposite sex.
What is interphase?
The period of time when the cell is not dividing.
What occurs during interphase?
Chromosomes elongate and become chromatin, DNA replication, mitochondrion & chloroplast production.
What is mitosis?
A period of division in the cell.
What is produced during mitosis?
2 cells that have identical DNA.
Does mitosis retain the number of chromosomes?
Yes.
What happens during prophase?
Chromosomes contract, spindle fibres appear, and the nuclear membrane begins to dissolve.
What characterizes metaphase?
Nuclear membrane is dissolved, chromosomes become thicker and line up in the middle of the cell, spindle fibres join to the chromosomes.
What occurs during anaphase?
Spindle fibres attach to each chromosome and pull them apart to opposite poles of the cell.
What happens during telophase & cytokinesis?
A nuclear membrane forms around the 2 new cells, and in animal cells, a cleavage furrow forms.
What forms in plant cells during cell division?
A cell plate forms
The cell plate is crucial for the separation of daughter cells in plant cell division.
What happens to chromosomes during interphase?
Chromosomes elongate again for interphase
Interphase is the phase where the cell prepares for division.
List the stages of mitosis.
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
These stages represent the process of cell division in eukaryotic cells.
What is the function of mitosis for single-celled organisms?
Asexual reproduction
Mitosis allows single-celled organisms to reproduce by creating identical offspring.
What is the function of mitosis for multi-cellular organisms?
Growth and repair
Mitosis is essential for replacing damaged cells and facilitating growth.
What type of cell division is meiosis?
A type of cell division
Meiosis is specifically involved in producing gametes.
How many cell divisions occur during meiosis?
2 cell divisions
This is in contrast to mitosis, which has only 1 cell division.
What effect does meiosis have on the number of chromosomes in a cell?
Halves the amount of chromosomes
This reduction is crucial for maintaining genetic diversity during sexual reproduction.
What types of cells does meiosis produce?
- Gametes
- Sperm
- Egg cells
These cells are essential for sexual reproduction in both plants and animals.
Why is meiosis important for sexual reproduction?
Needed for sexual reproduction and variation of genetic material
Meiosis contributes to genetic diversity in offspring.
What is a tumor?
A mass where one or more cells lose the ability to control the rate of mitosis and cell division
Tumors can be benign or malignant.
What characterizes benign tumors?
Usually not life threatening
Benign tumors do not invade surrounding tissues or spread.
What are malignant tumors commonly referred to as?
Cancers
Malignant tumors are dangerous due to their invasive nature.
What occurs when cells lose the ability to control mitosis?
Cancer occurs
This uncontrolled division leads to tumor formation and potential spread.
Why are malignant tumors considered dangerous?
- Cells never stop dividing
- They invade other tissues
- They may spread from one body part to another
These characteristics make malignant tumors difficult to treat.
What causes cancer?
Caused by carcinogens
Carcinogens are substances that can lead to cancer development.
