Biology unit 8

Why do cells need to divide?

For growth, repair, replacement of damaged cells and asexual reproduction

What is the cell cycle?

The series of events a cell goes through as it grows, copies, DNA, and divides

What are the three parts of interphase?

G1,S, and G2

What happens in G1 phase?

The cell grows and performs normal functions

What happens in S phase?

DNA is replicated (copied)

What happens in G2 phase?

The cell prepares for mitosis by making proteins and organelles

What is mitosis?

The division of the nucleus that creates two identical nuclei

List the phases of mitosis in order

Phrophase →Metapase → Anaphase → Telophase → Cytokenesis

What happens in prophase?

Chromosomes condense and become visible; Nuclear membrane breaks down

What happens in metaphase?

Chromosomes line up in the middle of the cell

What happens in anaphase?

Sister chromatids separate and move to opposite sides of the cell

What happens in telophase?

New nuclear membranes form and chromosomes uncoil

What is cytokinesis?

The division of cytoplasm forming two seperate two daughter cells

Whats a chromosome?

A structure made of DNA that carries genetic information

What are sister chromatids?

Identical copies of chromosome joined the centromere

When do sister chrmoatids form and why?

During S phase so each daughter cell gets identical DNA

How do daughter cells compare to the parent cell after mitosis?

They have the same number of chromosomes and identical DNA

What are cell cycle checkpoints?

Control points that ensure the cell is ready to move to the next phase

What is cellular differentiation?

The process by which cells become specialized for specific functions

How does differentiation help development?

It creates different cell types needed to form tissues and organs

What is selective gene expression?

When certian genes are turned on or off to make a cell specialized

How do genes control cell differentiation?

Genes can be activated or repressed to determine cell function

What is a stem cell?

An unspecialized cell that can divide and become different types of of cells

What is a somatic cell

Found in bone marrow or fat, limited ability to change, multipotent stem cell meaning they can only divide into more stem cells or can only become a few cell types.

What are embryonic stem cells?

Stem cells from embryos that can become almost any cell type

What are adult stem cells (somatic)?

stem cells found in adult tissues that repair and maintain them

What are induced pluripotent stem cells?

Adult cells that have been turned back to embryonic stem cells to be used to research

What does pluripotent mean?

Can become many different cell types

What does multipotent mean

can become limited range of cell types

Why are stem cells medically important?

they can be used for tissue repair, disease treatment and research

Which stem cells raise the most ethical concerns

Embryonic stem cells

What are induced pluripotent cells

Induced pluripotent stem cells are cells that are already differentiated that are "induced" to go back to a state of pluripotency so that they might differentiate into a different kind of cell.

stem cells are only present in multicellular organisms that have many different types of cells?

True

processes is most responsible for the size increase of the embryo?

mitosis

In which phase does a typical cell spend most of its time?

interphase

What is the first stage

Interphase

What is the second stage

Prophase

What is the third stage

Metaphase

What Is the fourth stage

anaphase

What is the fifth stage

telophase