BIO 122 Chapter Notes - Chapter 12: Sister Chromatids, Cell Division, Cytokinesis

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plumdinosaur511

17 Nov 2016

School

University of Hartford

Department

Biology - A&S

Course

BIO 122

Professor

Andrew Koob

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Chapter 12

Cell Cycle

I) Roles of Cell Division

● Cell division - reproduction of cells

○ Proks divide → reproducing new organism

● Cell cycle - life of a cell from the time it is first formed during the division of a parent cell

until its own division into two daughter cells

○ Pass identical genetic material to cellular offspring is crucial function of cell

division

■ Breakdown in cell cycle → cancer development

○ DNA → to two daughter cells

● Genome - endowment of DNA, genetic information

○ Before cell can divide:

■ DNA copied (replicated)

■ Two copies [DNA] separated each daughter cell ends up with complete

genome

○ Chromosomes - Packaged DNA molecules

■ Euk chromosomes one very long linear DNA molecule with many proteins

■ Carries genes - inherited traits

■ Proteins maintain structure and control activity of genes

○ Chromatin - complex of DNA and proteins building material of chromosomes

○ Somatic cells - all body cells (except reproductive cells)

■ # varies among species

■ Contain 46 chromosomes (2 sets of 23)

○ Gametes - reproductive cells (sperm and egg)

■ 23 chromosomes - Half as many chromosomes

II) Distribution of Chromosomes during Euk Cell Division

● Each duplicated chromosomes have two sister chromatid

○ Sister chromatid - joined copies of original chromosomes

1) Sister chromatid cohesion - Chromatids w/ identical DNA attached along lengths by

protein complexes

a) Centromere - region of chromosomal DNA where the chromatid is attached most

closely to sister chromatid

b) Attachment is mediated by proteins bound to centromeric DNA other bound

proteins condense DNA giving duplicated chromosomes a narrow “waist”

2) Two sister chromatids of each duplicated chromosome separate and move into two new

nuclei - form at ends of end of cell

a) Sister chromatids → individual chromosomes - doubles chromosomes in cell

● Mitosis - division of genetic material in nucleus

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● Followed by cytokinesis - division of cytoplasm

Chromosome duplication and distribution during cell division

1) Multiple chromosomes in euk cells - not duplicated

a) Long thin chromatin fiber w/ 1 DNA molecule and associated proteins

2) Duplicated - chromosome has 2 sister chromatids completely connected (sister

chromatid cohesion)

a) Containing copy of DNA molecule

3) Molecular and mechanical processes separate sister chromatids → 2 chromosomes and

create 2 daughter cells

● Meiosis - cell division w/ daughter cells one set of chromosomes half as many

chromosomes as parent cell

○ Humans - ovaries and testes

○ Fertilization fuses two gametes together and returns the chromosome number to

46 (two sets)

III) Phases of Cell Cycle

● Cell grows producing proteins and cytoplasmic organelles - mitochondria and ER

● Mitotic (M) phase - both mitosis and cytokinesis - shortest part cell cycle

● Interphase - 90% of cycle

■ Intense metabolic activity

○ G1 phase - cell grows

○ S phase - copies chromosomes

○ G2 phase - grows some more

■ Nuclear envelope enclose nucleus

■ Contains more than one nucleoli

■ 2 centrosomes formed by duplications of centrosome

● Centrosomes - regions in animal cells organize microtubules of

spindle

○ M phase - divides

Mitosis Phases

1) Prophase

a) Chromatin fibers - tightly coiled - condense chromosomes

b) Nucleoli disappear

c) Duplicated chromosome appear identical sister chromatids - joined at

centromeres - all along arms by cohesin

d) Mitotic spindle form- centrosomes and microtubules extend from them

e) Centromeres move away from each other - propelled by lengthening

microtubules

2) Prometaphase

a) Nuclear envelope fragments

b) Microtubules - extend from centrosome - invade nuclear area

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Document Summary

Cell cycle - life of a cell from the time it is first formed during the division of a parent cell until its own division into two daughter cells. Pass identical genetic material to cellular offspring is crucial function of cell division. Breakdown in cell cycle cancer development. Genome - endowment of dna, genetic information. Two copies [dna] separated each daughter cell ends up with complete genome. Euk chromosomes one very long linear dna molecule with many proteins. Proteins maintain structure and control activity of genes. Chromatin - complex of dna and proteins building material of chromosomes. Somatic cells - all body cells (except reproductive cells) Contain 46 chromosomes (2 sets of 23) Gametes - reproductive cells (sperm and egg) 23 chromosomes - half as many chromosomes. Ii) distribution of chromosomes during euk cell division. Each duplicated chromosomes have two sister chromatid. Mitosis - division of genetic material in nucleus. Followed by cytokinesis - division of cytoplasm.

Related Questions

1)What experiment was performed that allowed for scientists to finally agree that DNA is the genetic material within living organisms?

a.Understand the materials and scientific techniques used to come to this result.

2)What group of experiments led to the discovery of the mechanism used in DNA replication?

a.Understand the materials and scientific techniques used to come to this result.

i.What is a cesium chloride gradient?

ii.Where do 14N and 15N respectively fall along this gradient?

b.The results revealed that DNA replicates using which of the three proposed models?

i. Describe the mechanism of each model.

3)What is the role of the following proteins in DNA replication?

a.Helicase

b.Single strand binding proteins

c.Topoisomerase

d.DNA polymerase III

e.DNA polymerase I

f.Primase

g.Ligase

4)What extra steps are taken to be sure the lagging strand does not shorten each time DNA is replicated?

a.What is the role of telomerase in these âstepsâ?

5)In DNA repair, which enzyme has âproof-readingâ capabilities?

1)Which type of cells within our bodies use mitosis to reproduce?

2)Does mitosis create a cell that is different or the same as the parent cell undergoing division?

3)Describe the DNA found in sister chromatids.

4)Describe the DNA found in homologous chromosomes.

5)What occurs during the following stages of the cell cycle?

a.G₁ Phase

b.S Phase

c.G₂ Phase

d.M Phase

What are the phases of mitosis? What events occur in each phase?

1)Does mitosis separate homologous chromosomes, sister chromatids, or both?

2)What is cytokinesis?

a.Which fibers of the cytoskeleton contract to pinch parent and daughter cells apart from one another in animals?

b.How do microtubules move chromosomes to the two poles of a dividing cell?

3)How are centrioles involved in this process?

a.How do plants form two complete cells during cytokinesis?

4)How do bacterial cells reproduce?

5)The cell cycle is controlled at âcheckpointsâ. What occurs at each of the following checkpoints?

a.G₁ Checkpoint

b.G₂ Checkpoint

c.M Checkpoint

6)How do cyclin and cdk act to control the G2 checkpoint?

7)If presented with the schematic of the M checkpoint, you should be able to explain perturbations to the system as well as if the cell will divide or stall at metaphase.

8)Cancerous cells form when the cell cycle checkpoints do not function correctly and continues to divide even though it is damaged in some way. How does the protein p53 function to keep these cells from dividing?

9)Normal cells follow certain rules of growth that cancerous cells do not follow. What are these rules (provide a short definition for each as well)?

10)What is the difference between a benign tumor and a malignant tumor?

indigohedgehog242

1)What are the inputs of photosynthesis?

2)What are the outputs of photosynthesis?

3)Light-Dependent Reactions

Where does the first stage of photosynthesis, the light-dependent reactions, occur within a chloroplast?

Where does the energy come from that drives these reactions?

What molecule donates an electron to the reaction center of photosystem II?

How is the energy of an electron changed as it moves along the ETC?

How does the electrical charge of the thylakoid membrane affect protons (H+) within the chloroplast?

Where does the electron that is donated to photosystem I come from?

What are the final products of this series of reactions?

What happens to each of the final products from this series of reactions?

4)Light-Independent Reactions (Calvin Cycle)

a.Where does the second stage of photosynthesis, the Calvin Cycle, occur within a chloroplast?

b.What are the direct inputs for these reactions?

c.What are the three steps to the Calvin cycle?

d.What are the final products of this reaction?

e.What role does rubisco play in the Calvin Cycle?

1)What experiment was performed that allowed for scientists to finally agree that DNA is the genetic material within living organisms?

a.Understand the materials and scientific techniques used to come to this result.

2)What group of experiments led to the discovery of the mechanism used in DNA replication?

a.Understand the materials and scientific techniques used to come to this result.

i.What is a cesium chloride gradient?

ii.Where do 14N and 15N respectively fall along this gradient?

b.The results revealed that DNA replicates using which of the three proposed models?

i. Describe the mechanism of each model.

3)What is the role of the following proteins in DNA replication?

a.Helicase

b.Single strand binding proteins

c.Topoisomerase

d.DNA polymerase III

e.DNA polymerase I

f.Primase

g.Ligase

4)What extra steps are taken to be sure the lagging strand does not shorten each time DNA is replicated?

a.What is the role of telomerase in these âstepsâ?

5)In DNA repair, which enzyme has âproof-readingâ capabilities?

1)Which type of cells within our bodies use mitosis to reproduce?

2)Does mitosis create a cell that is different or the same as the parent cell undergoing division?

3)Describe the DNA found in sister chromatids.

4)Describe the DNA found in homologous chromosomes.

5)What occurs during the following stages of the cell cycle?

a.G₁ Phase

b.S Phase

c.G₂ Phase

d.M Phase

What are the phases of mitosis? What events occur in each phase?

1)Does mitosis separate homologous chromosomes, sister chromatids, or both?

2)What is cytokinesis?

a.Which fibers of the cytoskeleton contract to pinch parent and daughter cells apart from one another in animals?

b.How do microtubules move chromosomes to the two poles of a dividing cell?

3)How are centrioles involved in this process?

a.How do plants form two complete cells during cytokinesis?

4)How do bacterial cells reproduce?

5)The cell cycle is controlled at âcheckpointsâ. What occurs at each of the following checkpoints?

a.G₁ Checkpoint

b.G₂ Checkpoint

c.M Checkpoint

6)How do cyclin and cdk act to control the G2 checkpoint?

7)If presented with the schematic of the M checkpoint, you should be able to explain perturbations to the system as well as if the cell will divide or stall at metaphase.

9)Normal cells follow certain rules of growth that cancerous cells do not follow. What are these rules (provide a short definition for each as well)?

10)What is the difference between a benign tumor and a malignant tumor?

amberkoala41

Chapter 6: How Cells Harvest Chemical Energy

What is the difference between photosynthesis and cellular respiration?

How do cells capture the energy released by cellular respiration?

What are the products of cellular respiration?

What does pyruvate do?

The conversion of CO2 and H2O into organic compounds using energy from light is called what?

If ATP accumulates in a cell, what happens?

A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because the drug inhibits what?

As a result of glycolysis, there is a net gain of ________ ATP(s).

Which of the following is a result of glycolysis?

The enzymes of the citric acid cycle are located in what?

Chapter 7 Photosynthesis: Using Light to Make Food

What is the name given to organisms that can make their own food and thus sustain themselves without consuming organic molecules derived from other organisms?

What is an example of a photoautotroph?

What is the origin of chloroplasts?

In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called what?

The oxygen released into the air as a product of photosynthesis comes from what?

What is the use and production of CO₂ in both photosynthesis and cellular respiration?

Know the parts of the chloroplast. Which structure in the chloroplast represents the thylakoid membrane?

What molecules are reactants of photosynthesis?

What is the source of energy that provides the boost for electrons during photosynthesis?

Why are most plants green?

Chapter 8: The Cellular Basis of Reproduction and Inheritance

What is called the creation of genetically identical offspring by a single parent, without the participation of sperm and egg?

How do eukaryotic chromosomes differ from prokaryotic chromosomes?

Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures are called what?

Eukaryotic cells spend most of their cell cycle in which phase?

What occurs during interphase?

What is the process called by which the cytoplasm of a eukaryotic cell divides to produce two cells?

What is the phase of mitosis during which the mitotic spindle begins to form?

During which phase of mitosis does the nuclear envelope re-form?

What feature of plant cell division distinguishes it from animal cell division?

What features likely accounts for the difference between plant and animal cell cytokinesis?

What must occur for a plant or animal to grow and develop normally?

Chapter 9: Patterns of Inheritance

Most genetic disorders of humans are caused by what type of alleles?

What is the difference between genotypes and phenotypes?

What are the individual features of all organisms?

What does the chromosome theory of inheritance state?

What is the normal complement of sex chromosomes in a human male?

The sex chromosome complement of a normal human female is what?

How many sex chromosomes are in a human gamete?

What is the gene located on a sex chromosome called?

Why are sex-linked conditions more common in men than in women?

Chapter 12: DNA Technology and Genomics

How long has Biotechnology been around?

What do restriction enzymes do?

What are "Sticky ends"?

What is the best definition of a genomic library?

What is a nucleic acid probe?

The only cells that can correctly attach sugars to proteins to form glycoprotein products are what?

How does a vaccine work?

What is the preferred name of the technique used to determine if DNA comes from a particular individual?

The polymerase chain reaction relies upon unusual, heat-resistant ________ that were isolated from bacteria living in hot springs.

Gel electrophoresis sorts DNA molecules on the basis of their what?

BIO 122 Chapter Notes - Chapter 12: Sister Chromatids, Cell Division, Cytokinesis

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