Which of the following is a component of a chromosome?
A.
Centromere
B.
Gamete
C.
Homologue
D.
Ribose
The Correct Answer and Explanation is:
The correct answer is A. Centromere.
Explanation:
A chromosome is a long, continuous thread of DNA that contains many genes, regulatory elements, and other nucleotide sequences. It plays a crucial role in cell division, allowing genetic information to be accurately passed from one generation to the next. The centromere is a fundamental component of a chromosome.
Centromere:
The centromere is a specific region of a chromosome where the two sister chromatids are joined together. It is crucial for chromosome movement during cell division. During mitosis and meiosis, the centromere provides the attachment point for spindle fibers, which are structures that pull the chromatids apart to opposite poles of the cell. This ensures that each daughter cell receives an accurate number of chromosomes. The centromere is characterized by a distinct DNA sequence and associated proteins, which form the kinetochore, a structure essential for chromosome segregation.
Gamete:
A gamete is not a component of a chromosome but rather a type of cell involved in sexual reproduction. Gametes are sperm cells in males and egg cells in females. Each gamete contains half the number of chromosomes found in somatic cells. During fertilization, two gametes combine to form a zygote, which has a full set of chromosomes.
Homologue:
Homologues refer to chromosomes that are similar in shape, size, and genetic content but are not the same chromosome. Each individual has a pair of homologous chromosomes, one inherited from each parent. These homologous chromosomes pair up during meiosis but are not components of a single chromosome.
Ribose:
Ribose is a sugar molecule that is a component of RNA, not DNA. It is part of the nucleotide structure in RNA and is not found as a standalone component of a chromosome. DNA, the molecule that makes up chromosomes, contains deoxyribose sugar, which differs from ribose.
In summary, the centromere is a key structural component of a chromosome that plays a critical role in cell division and chromosome segregation.