Short Definitions Of

We are going to learn about some topics, In Short words, So you all can learn Easily.

1. Cell Division: It can be defined as a method of producing new cells from pre-existing cells by their division, in such a way that the daughter cells receive the same hereditary material (chromosomes) as present in the parent cell.

2. Mitosis: It is a type of cell division during which a cell divides into two daughter cells, each containing similar and same the number of chromosomes as present in the parent cell.

3. Meiosis : It is a type of cell division in which a cell undergoes two successive divisions producing four daughter cells, each containing half the number of chromosomes as compared to the parent cell.

4. Amphiastral spindle : Spindle (mitotic apparatus) having two asters, one at each pole.

5. Anastral spindle : Spindle without asters and is found in plant cells.

6. Centromere : Point on chromosome where the two chromatids of each chromosome are attached.

7. Chromatin reticulum : Network of genetic material in the nucleus of non-dividing cells.

8. Chromosome: Thick rod like structure bearing genes, present in the nucleus.

9. Cytokinesis : Division of cytoplasm.

10. Diploid : A cell in the nucleus of which chromosomes are present in the form of pairs (2n) (2-set of chromosomes).

11. Equator: Middle of the spindle, in between the two poles, from where it is widest.

12. Eukaryote : A cell with advanced nucleus covered by nuclear envelope.

13. Gene: A small segment of chromosome that carries one character from parent to the offsprings.

14. Generation time : Duration between two successive cell divisions.

15. Haploid (n): A cell, in the nucleus of which, each type of chromosome is one in number. (one set of chromosome).

16. Heterotypic division : A division in which the

daughter cells produced are not exactly alike, but have different genetic constitution.

17. Homologous chromosomes : Pair of chromosomes which are exactly similar and bear same genes at same loci.

18. Interkinesis : Brief non-dividing period of variable duration between karyokinesis of meiosis - I and meiosis -II.

19. Interphase : Non-dividing preparatory period or growth period of a newly formed cell upto the begi ing of its karyokinesis.

20. Karyokinesis : Division of nucleus.

21. Maternal chromosomes : Chromosomes which are shared by the female parent.

22. Meiocytes : Cells which undergo meiotic division.

23. Mitotic phase : Dividing phase of cell cycle.

24. Paternal chromosomes : Chromosomes shared by the male parent.

25. Tetrad : Pair of homologus chromosomes showing four chromatids.