Across
- 2. each of the two threadlike strands into which a chromosome divides longitudinally during cell division. Each contains a double helix of DNA.
- 4. a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division.
- 6. plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants it consists mainly of cellulose.
- 7. the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.
- 11. a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material.
- 12. the semipermeable membrane surrounding the cytoplasm of a cell.
- 13. a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
- 15. a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
- 16. the first stage of cell division during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears. includes the reduction division.
- 18. a basic unit of heredity and a sequence of nucleotides in DNA
- 19. the final phase of cell division, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.
Down
- 1. the stage of meiotic or mitotic cell division in which the chromosomes move away from one another to opposite poles of the spindle.
- 3. an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae).
- 5. (in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.
- 7. the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body
- 8. a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
- 9. the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.
- 10. the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis.
- 14. form a protein structure that divides the genetic material in a cell. necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis.
- 17. the second stage of cell division, during which the chromosomes become attached to the spindle fibers.