Chromosome Behavior in Mitosis and Meiosis

The video explains chromosome numbers in mitosis and meiosis. It describes how a chromosome with two sister chromatids is considered one unit until they separate. In mitosis, human body cells start with 46 chromosomes, duplicate them, and end with two identical cells, each with 46 chromosomes. In meiosis, cells also start with 46 chromosomes, duplicate them, but end with four cells, each having 23 chromosomes, effectively halving the original number.

What is the key factor that determines whether two sister chromatids are considered one chromosome?

• Their shape

• Their color

• Whether they are attached

• Their size

How many chromosomes do human body cells typically have during mitosis?

• 46

• 23

• 69

• 92

At what stage do chromosomes duplicate in mitosis?

• Metaphase

• Prophase

• Telophase

• Interphase

How many chromosomes are present in each daughter cell after mitosis in humans?

• 23

• 92

• 46

• 69

What is the chromosome number in each cell after meiosis and cytokinesis in humans?

• 23

• 46

• 92

• 69