Lect 14 - cell division- mitosis

Flashcards for reviewing key concepts related to cell division and mitosis.

What is a karyotype?

An ordered, visual representation of all the chromosomes in a cell.

What are homologous chromosomes?

A pair of chromosomes with the same genes, one paternal and one maternal.

What is the location of a gene called?

Locus

What is a gene?

A defined region of DNA that produces a type of RNA molecule with some function; a unit of hereditary information.

What is an allele?

An alternative version of a gene.

What occurs during the mitotic phase of the cell cycle?

Mitosis (distribution of chromosomes into two daughter nuclei) and cytokinesis (division of cytoplasm producing two daughter cells).

What are duplicated chromosomes composed of?

Two sister chromatids which are genetically identical.

What happens to sister chromatids during mitosis?

They separate.

Describe the G2 phase of interphase.

Nuclear envelope intact, nucleolus visible, two centrosomes form, duplicated chromosomes not yet condensed.

How many daughter cells are produced during mitosis?

Two

Are daughter cells genetically identical to mother cell?

Yes, they are genetically identical.

What happens to nucleoli during prophase?

They disappear.

What happens to chromosomes during prophase?

They condense and appear as two identical sister chromatids joined at centromeres.

What begins to form from centrosomes during prophase?

Mitotic spindle

What happens to the nuclear envelope during prometaphase?

It breaks down.

What forms at the centromere of each chromatid during prometaphase?

Kinetochore

What are kinetochore microtubules?

Microtubules that attach to the kinetochores.

How do nonkinetochore microtubules lengthen the cell?

By interacting with those from the opposite pole of the spindle.

Where are centrosomes located during metaphase?

At opposite poles of the cell.

How are duplicated chromosomes aligned during metaphase?

At the metaphase plate.

What happens to sister chromatids during anaphase?

They disjoin at centromeres and each chromatid becomes an independent daughter chromosome.

How do daughter chromosomes move towards opposite poles during anaphase?

As kinetochore microtubules shorten.

What causes the cell to elongate during anaphase?

The nonkinetochore microtubules lengthen.

What is the state of chromosomes during telophase?

Become less condensed (become longer).

What reappears during telophase?

Nucleoli

What happens to the cytoplasm during cytokinesis?

It divides resulting in two daughter cells.

How do animal cells divide during cytokinesis?

Formation of a cleavage furrow, pinching the cell in two.

How do plant cells divide during cytokinesis?

Formation of cell plate between daughter cells.

How many copies of each duplicated chromosome does each daughter cell have after mitosis and cytokinesis?

One copy of each duplicated chromosome.