Biology
Answer
Duplicated chromosomes consist of two identical strands, each of these is called a chromatid. Before replication, one chromosome is composed of one DNA molecule. In replication, the DNA molecule is copied, and the two molecules are known as chromatids. During the later stages of cell division these chromatids separate longitudinally to become individual chromosomes.
Related Questions
The diagram given below represents a certain phenomenon which occurs during meiosis. Name and explain the phenomenon by using the terms - homologous chromosomes, chromatids, and crossing-over.
Given below is a diagram representing a stage during mitotic cell division in an animal cell. Examine it carefully and answer the questions which follow.
(a) Identify the stage. Give one reason in support of your answer.
(b) Name the cell organelle that forms the 'aster'.
(c) Name the parts labelled 1, 2 and 3.
(d) Name the stage that follows the one shown here. How is that stage identified?
(e) Mention two points of difference between mitosis and meiosis with regard to:
- The number of daughter cells produced.
- The chromosome number in the daughter cells.
Given below are three diagrammatic sketches (A, B and C) of one and the same particular phase during mitotic type of cell division.
(a) Identify the phase.
(b) What is the diploid number of chromosomes shown in them?
(c) Identify whether these are animal cells or plant cell? Give reasons.
Shown below are four stages (A, B, C, D) (not in sequence) of a certain kind of cell division.
(a) Is it a plant cell or an animal cell? Give two reasons.
(b) Is it undergoing mitosis or meiosis?
(c) What should be the correct sequence of these four stages among themselves?
(d) Name the stage that should precede the earliest of these stages.
(e) Draw the stage named above inside the blank space provided.