Ch.12 Cell Cycle

DNA replication occurs in…?

S phase of interphase in somatic and reproductive cells

How many chromatids does a human somatic cell have after interphase & just prior to mitosis?

92 chromatids

Normal state: 23 pairs

Interphase: 42 × 2 because of the two sister chromatids

Observation of cancer cells in culture support the hypothesis that cancel cells…?

Don’t exhibit density-dependent inhibition

What occurs during pro-metaphase of mitosis?

Nuclear envelope fragments/ dissolves

During interphase, genetic material of a eukaryotic cell is…?

Dispersed in the nucleus as long strands of chromatin

What occurs during anaphase?

Identical chromatids move to opposite poles

Centromeres divide

Centrioles are at opposite sides

Spindle made of microtubules is present

How does mitosis differ between most eukaryotes & others like diatoms & dinoflagelles?

The nuclear envelope fragments/disappears in most eukaryotes but remains intact in diatoms and dinoflagellates

What occurs during telophase of mitosis?

2 distinct daughter nuclei form in the cell

What occurs during anaphase of mitosis?

Sister chromatids are pulled apart toward opposite sides of the cell

Difference between a dividing cell in a plant cell and animal cell?

Cell plate

Difference between mitosis and binary fission?

Binary fission involves replication and division of a single chromosome

Mitosis involves division of multiple, replicated chromosomes

Which structure is part of the mitotic spindle?

Centrosome

Nonkinetochore microtubules

Aster

Kinetochore microtubules

Difference between benign tumor and malignant tumor?

Cells of benign tumors don’t metastasize; malignant tumors do

What occurs during metaphase of mitosis?

Chromosomes align along metaphase plate

A cell containing 40 chromatids at the beginning of mitosis will have how many chromatids at the end of cytokinesis?

20

Cytokinesis means…?

Division of cytoplasm

The complex of DNA and protein that makes up a eukaryotic chromosome is called…?

Chromatin

In animal cell mitosis, during which phase does the cleavage furrow form?

Cytokinesis

Chromatids are…?

Identical copies of each other if they’re part of the same chromosome

What is the spread of cancer cells to other body locations called?

Metastasis

During binary fission involves replication a bacterium…?

The origins of replication move apart

What occurs during prophase?

The beginning formation of a spindle apparatus

Which doesn’t occur during prophase of mitosis?

The mitotic spindle breaks down

Which doesn’t occur during interphase?

Separation of sister chromatids

Which phase of mitosis is the opposite of pro-metaphase in terms of the nuclear envelope?

Telophase

Which describes a cell that undergoes mitosis but not cytokinesis?

The cell contains more than one nucleus

What are the cell cycle checkpoints for?

All of the above

May cells working together is…?

Tissue

A tumor is caused by…?

Uncontrolled growth of cancerous cells

Which doesn’t occur during interphase?

Dividing

In which phase does the cell grow?

G1 & G2 only

Important function happening in S phase?

Synthesizing DNA

Which phase doesn’t have a checkpoint?

S phase

What is apoptosis?

When the cell self-destructs, it ensures that irreparable cells won’t divide

What is Cdk?

Cyclin- dependent kinase

What is cyclin?

A protein bounded to Cdk, tells the cell to move on to the next cell cycle phase

What is the cell doing in G0?

Carrying out their cellular function

Which is true about bacteria?

Bacteria gas DNA

What does bacteria lack?

Nucleus and other membrane bound organelles

What is binary fission?

Asexual reproduction, they divide to make a copy of themselves

Bacteria share their plasma in a process called…?

Conjugation

What is bacteria transformation?

When bacteria take in DNA from their environment

What is the role of an endospore?

Allows bacteria to survive in hostile environments , lack of nutrients, coldness

What are extremophiles?

Bacteria and types of archaea, they survive in extreme environments, excessive heat, chemicals that our cells would find toxic, radiation

Which cells divide frequently in humans?

Cells in our digestive tract and skin

Why is it important that the cell “slows” down to replicate it’s DNA?

It helps prevent mistakes, or mutations, in the new copy of DNA

T/ F by the end of S phase, the cell has 2 copies of its genetic code

True

Why must DNA replication occur prior to cell division?

Cells need 2 copies of DNA prior to cell division so that the each new cell will have an identical copy of DNA

What’s the technical term for “noodles” or loose-stringy form of DNA.

Chromatin

Centrosomes (centrioles) necessary for cell division appear during which phase?

G2

What are the 2 steps for the mitotic phase?

Mitosis and cytokinesis

How can cancer arise as a result of the cell cycle?

The genes and proteins regulating various “checkpoints” throughout the cell cycle stops working correctly and cell cycle breaks down

What happens during telophase?

All of the above

What are microtubules?

Microtubules are made up of subunits of tubulin, and are structures along which substances are transported in the cell.

How can a protein outside the cell cause events to happen inside the cell?

A protein outside the cell can bind to a receptor protein on the cell surface, causing it to change shape and sending a signal inside the cell.

What effect does phosphorylating a protein have on that protein?

Phosphorylation changes the shape of the protein, most often activating it.