Question

d) mitotic spindle formation begins and attaches to the centromeres of chromosomes

1. the 2nd stage of mitosis, metaphase, is defined by the following process:

a) the nuclear envelope/membrane and nucleolus dissolve
b) mitotic spindle pulls the chromosomes to opposite poles of the cell
c) centrioles cluster and align in the middle of the cell, midway between the chromosomes that are at opposite end of the cell
d) chromosomes cluster and align in the middle of the cell, midway between the centrioles that are at opposite ends of the cell

1. during telophase:

a) chromosomes uncoil to become thread - like chromatin again
b) mitotic spindle reassemble to form the nuclear membrane around the chromatin mass
c) nuclear envelope/membrane forms around each chromatin mass and nucleoli appear in each nucleus
d) both a) and b) occur during telophase
e) both a) and c) occur during telophase

1. during anaphase:

a) centromeres that hold the sister chromatids together split apart into two identical independent chromosomes
b) separated chromosomes are pulled by spindle to opposite poles of cell
c) the nuclear envelope/membrane and nucleolus reassemble.
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Explanation:

1. In metaphase of mitosis, chromosomes align at the cell - equator (middle of the cell) between the centrioles at opposite ends. This is a key characteristic of metaphase.
2. During telophase, chromosomes uncoil to become chromatin and the nuclear envelope forms around each chromatin mass and nucleoli reappear.
3. In anaphase, centromeres holding sister chromatids split and the separated chromosomes are pulled to opposite poles of the cell. The nuclear envelope does not reassemble in anaphase.

Answer:

1. d) Chromosomes cluster and align in the middle of the cell, midway between the centrioles that are at opposite ends of the cell
2. e) Both a) and c) occur during telophase
3. a) Centromeres that hold the sister chromatids together split apart into two identical independent chromosomes; b) Separated chromosomes are pulled by spindle to opposite poles of cell