Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Humans have a total of 46 chromosomes. Which statement is true regarding sister chromatids in humans?
A
Sister chromatids are identical copies of a chromosome connected by a centromere.
B
Sister chromatids are formed during meiosis and are not identical.
C
Sister chromatids are different chromosomes that pair up during mitosis.
D
Sister chromatids are only present in gametes.
Verified step by step guidance
1
Understand the concept of sister chromatids: Sister chromatids are identical copies of a single chromosome that are connected by a structure called the centromere. They are formed during the S phase of the cell cycle when DNA replication occurs.
Differentiate between mitosis and meiosis: In mitosis, sister chromatids are separated into two new nuclei, ensuring that each daughter cell receives an identical set of chromosomes. In meiosis, sister chromatids are also formed, but they are separated during the second division (meiosis II) to produce gametes.
Evaluate the statement about sister chromatids being identical: Since sister chromatids are formed by the replication of a single chromosome, they are identical copies of each other, barring any mutations.
Consider the context of meiosis: While sister chromatids are indeed formed during meiosis, they remain identical until crossing over occurs, which can introduce genetic variation. However, the fundamental definition of sister chromatids as identical copies remains true.
Clarify the presence of sister chromatids: Sister chromatids are present in all cells that undergo division, not just in gametes. They are a crucial part of both mitotic and meiotic processes, ensuring accurate distribution of genetic material.