cell cycle & mitosis

Flashcards covering key concepts from the lecture on the cell cycle and mitosis.

What is a characteristic of asexual reproduction?

one parent/mother cell divides to form 2 new daughter cells/offspring (new cells)

why? some organisms reproduce asexually to make more of themselves

Give an example of organisms that reproduce asexually.

Fungi (like yeast) and protists

Besides reproduction, what are two other reasons cells replicate?

Growth and tissue renewal, development, and repairing damaged tissues.

What are somatic cells?

Body cells (not germ cells like sperm or eggs) ex) skin, liver, heart, neurons, eyes

they go through the cell cycle/mitosis

What is the general process of cell replication?

Replication of DNA, DNA copies separated, cell splits to produce two genetically identical daughter cells.

What are the three stages of the eukaryotic cell cycle?

interphase- prep for division (DNA replication here)

mitosis- separates DNA into 2 new cells (about to form)

cytokinesis- physically separates the 2 daughter cells

What occurs during interphase?

DNA replication.

What occurs during mitosis (M-phase)?

DNA copies separated.

What occurs during cytokinesis (M-phase)?

Division of cytoplasm – cell splits in two.

What happens during the G1 phase of interphase?

Cell grows physically in size and makes proteins needed for DNA replication.

What happens during the S phase of interphase?

DNA is replicated.

What happens during the G2 phase of interphase?

Cell keeps growing, makes more organelles, and makes microtubules. (nearly finished growing)

What happens during prophase?

chromatin condenses into chromosomes (highly packaged DNA), microtubule spindle starts to assemble, centrosomes move to opposite ends/poles of the cell

What is the role of the centromere?

Holds the two sister chromatids together.

What is the role of the kinetochore?

Attaches a sister chromatid to spindle fibers.

What happens during prometaphase?

Nuclear envelope breaks down, microtubules attach to each sister chromatid at the kinetochores.

What happens during metaphase?

Chromosomes are arranged along the metaphase/equatorial plate (middle of cell), all chromosomes (sister chromatids) are attached to microtubules via kinetochores.

What happens during anaphase?

Sister chromatids separate and begin moving towards opposite poles.

each sister chromatid becomes a chromosome

What happens during telophase?

The chromosomes will decondense into chromatin, a nuclear envelope will form around each set of chromosomes, a cleavage furrow forms.

What happens during cytokinesis?

Division of cytoplasm, resulting in two daughter cells.

What is the importance of cell cycle checkpoints?

During mitosis, the cell must pass checkpoints to continue cell cycle properly. failure might result in death or or delay

What are cancer cells?

Cells that have lost control over cell division and divide uncontrollably. they ignore checkpoints, replicate in absence of a signal to go, proliferate in an uncontrolled manner

What is a benign tumor?

Abnormal cells remain only at the original site and stop growing. (not cancerous)

What is a malignant tumor?

Cancerous tumor that grows and spreads throughout the body. Metastasize (spreads to other tissues/organs)

What is metastasis?

Malignant tumors invade surrounding tissues and can metastasize.

cell cycle/ binary fission where?

cell cycle in eukaryotic cells (like humans)

binary fission (two split) in prokaryotic cells

mitotic spindle helps organize cell division

spindle made up of

microtubules- form the spindle

centrosomes - organize spindle

3 cell cycle check points

G1 - checks for enough food, DNA damage, growth signal

G2 - checks if cell size is good (big enough?), DNA replicated properly

Metaphase (M phase) - checking for microtuble attachment to every sister chromatid at kinetochore

2 major group of genes that control cell cycle

tumor supressor genes- slow down/ STOP cell cycle

proto-oncogenes - promote cell division (GO)