Materials and Methods. Ribonuclease.--Removal of ribonucleic acid from meristematic onion cells did not show any qualitative differences

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Materials and Methods. Ribonuclease.--Removal of ribonucleic acid from meristematic onion cells did not show any qualitative differences"

Transcription

1 B~U~ Noz~s 129 Alterations in Nuclear Ribonucleic Acid Metabolism Induced by l~inetin.* BY RUTH GUNMAN. From the Department of Genetics, University of California, Be, kezey.~ Kinetin, a substance recently isolated from deoxyribonucleic acid preparations (7), has been found to stimulate cell division in a number of plant tissues (7, 4). In meristematic cells of onion roots, low concentrations of kinetin--in addition to increasing the number of cells entering mitosis--also affected the relative durations of prophase and telophase, apparently shortening the former and increasing the durations of the latter. These phenomena were interpreted to be associated with an effect of the substance on the coiling cycle of the chromosomes during mitosis. The statistical and cytological evidence from the above study, as well as the findings of Serra (9), Kaufmann, McDonald, and Gay (6), Jacobson and Webb (5), Ris and Kleinfeld (8), Brachet (1), and especially of Firket, Ch~vremont- Comha~re, and Ch~vremont (2), led us to suspect that low concentrations of kinetin induced an accumulation of ribonucleic acid (RNA) in dividing nuclei of onion roots. The present study presents an attempt to test this hypothesis with the aid of cytochemical tests, in particular by means of enzymatic digestion of nucleic acids in onion roots grown in kinetin solutions. Materials and Methods Growing roots of onion were treated in 1 p.p.m, and 5 p.p.m, solutions of kinetin 1 for periods of 6, 24, 48, and 72 hours. Control * Aided by a special grant from the American Cancer Society, Inc., California Division. Receined for ~blication, August 6, Kindiy supplied by F. Skoog. J. BIolmyszc. AND Bxocm~. Crroz., 1957, Vok 3, No. 1 roots were immersed in distilled water for parallel periods. Immediately after treatment, the roots were fixed in 1:3 acetic alcohol, dehydrated, embedded, and sectioned longitudinally at 8 ~ thickness. Series of compound slides were prepared, each slide consisting of one ribbon of distilled water controls and one or more ribbons of kinetintreated material. Each ribbon, whether experimental or control, contained sections of two different roots. The slides of each series were divided into two groups: one was placed for I hour in an aqueous solution of ribonuclease (Worthington, 0.I per cent at 40 C. ph 6.8) and then stained with azure B bromide by a method similar to that of Flax and Himes (3). The second group was stained in the same manner after enzymatic removal of DNA: 1 mg./cc. Worthington deoxyribonuclease in aqueous gelatin Mg ++ solvent buffered at ph 6.9 and applied at 30 C. for 1 hour. For each enzyme treatment, parallel runs were made in water adjusted to the equivalent ph. The action of the deoxyribonuclease was tested by following one set of DNase-treated slides by Feulgen staining. The nuclei remained completely unstained. Azure B bromide stains DNA greenish blue, RNA purple. Extraction of all nucleic acids in TCA (5 per cent at 90 C. for 12 minutes), and subsequent azure staining also resulted in colorless slides. Because of the striking results obtained with deoxyribonuclease this part of the experiment was repeated, using a new series of kinetin treatments and new preparations of DNase solution and azure dye. The results of the second trial are entirely in agreement with the first. RESULTS AND DISCUSSION Ribonuclease.--Removal of ribonucleic acid from meristematic onion cells did not show any qualitative differences

2 130 BRIEF NOTES in DNA between treated roots and their controls. Both interphasic and mitotic nuclei were greenish blue while cytoplasm and nucleoli remained unstained. Deoxyribonuclease.--Fig. 1 shows a distilled water control stained with azure B after removal of deoxyribonucleic acid. The chromatin is almost colorless while cytoplasm and nucleoli are stained densely in varying shades of purple. Fig. 2 is a section of a root tip, from the same slide, which had been treated with 1 p.p.m, kinetin for 24 hours. Again cytoplasm and nucleoli are purple; however, in this root a striking amount of dye has also been bound by the nucleus apart from the nucleolus, indicating the presence of fairly high concentrations of ribonucleic acid in the chromatin after treatment with kinetin. Evidence for strongly stainable ribonucleic acid may be seen in interphasic as well as in mitotic nuclei (note prophase, metaphase, and telophase figures in Fig. 2), which are stained purple. Such increased quantities of nuclear RNA were observed in every root grown in 1 p.p.m, kinetin solution, as early as 6 hours after treatment and persisting through 72 hours. The higher concentration (5 p.p.m.) gave less consistent results, some roots showing evidence of increased nudear RNA while others did not differ markedly from the controls. This deviation is in agreement with a previous experiment (4), in which high concentrations of kinetin had caused variable amounts and expressions of toxicity. In that study, the 1 p.p.m, concentration was found to be the most effective in changing rates of cell division without producing observable cytological abnormalities. It appears that--as with growth hormones--the specific action of kinetin is effective only over a narrow range of concentrations. In the present study the lack of uniformity of response to the 5 p.p.m, solution also indicates that it is not kinetin taken up by the nuclei which is stained, but rather a compound resulting from the treatment. The results of the present experiment are in agreement with our assumption that kinetin does not interfere with synthesis of DNA before initiation of division or with DNA metabolism throughout mitosis. They provide evidence for the presence of greatly increased amounts of nuclear RNA following treatment with kinetin, though quantitative and/or biochemical data are still needed to prove conclusively such increases. The origin and role of this ribonucleic acid and its specific influence on the mitotic cycle are not clear at present and require further study. SUMMARY Removal of deoxyribonucleic acid from meristematic onion root ceils grown in solutions of kinetin, followed by metachromatic staining in azure B bromide, indicated the presence of appreciable amounts of ribonucleic acid in nuclei exposed to the cell division factor. The author is very much indebted to Dr. Max Alfert for help and advice offered throughout the course of the investigation and to Mrs. Norma O. Goldstein for expert assistance in the cytochemical procedures. BIBLIOGRAPHY 1. Brachet, J., Effects of ribonuclease on the metabolism of living root tip ceils, Nature, 1954, 174, Firket, H., Ch~vremont-Comhaire, S., and Ch~vremont, M., Action of ribonuclease on living cells in vitro and synthesis of DNA, Nature, 1955, 178, Flax, M. H., and Rimes, M. H., Microspectrophotometric analysis of recta-

3 BRIEF NOTES 131 chromatic staining of nucleic acids, Physiol. Zool., 1952, 25, Guttman, R., Effects of kinetin on cell division, with special reference to initiation and duration of mitosis, Chromosoma, 1956, 8, Jacobson, W., and Webb, M., The two types of nucieoprote'ms during mitosis, Exp. Cell Research, 1952, 3, Kaufmann, B. P., McDonald, M. R., and Gay, H., The ribonucle~c acid content of chromosomes, Genetics, 1948, 33, Miller, C. O., Skoog, F., yon Saltza, M. H., and Strong, F. M., Kinetin, a cell division factor from deoxyribonucleic acid, J. Am. Chem. Sot., 1955, 77, Ris, H., and Kleinfeld, R. K., Cytochemical studies on the chromatin elimination in Sdenobia (Lepidoptera), Chromosoma, 1952, 5, Serra, J. A., Composition of chromonemata and matrix and the role of nucleoproteins in mitosis and meiosis, Cold SFfing Harbor Syrup. Quant. Biol., 1947, 12, 192.

4 132 BRIEF NOTES EXPLANATION OF PLATE 22 Onion root meristem cells after removal of DNA with deoxyribonuclease, stained with azure B bromide. FxG. 1. Section of control root. X 900. FIG. 2. Same slide, section of root treated with 1 p.p.m, kinetin for 24 hours. X 900. (P -- prophase, M = metaphase, T == telophase.)

5 THE JOURNAL OF BIOPHYSICAL AND BIOCHEMICAL CYTOLOGY PLATE 22 VOL. 3 (Guttman: Alterations in RNA metabolism induced by kinetin)

Biology 3A Laboratory MITOSIS Asexual Reproduction

Biology 3A Laboratory MITOSIS Asexual Reproduction Biology 3A Laboratory MITOSIS Asexual Reproduction OBJECTIVE To study the cell cycle and understand how, when and why cells divide. To study and identify the major stages of cell division. To relate the

More information

BIOL100 Laboratory Assignment 4: Mitosis and Meiosis. Name:

BIOL100 Laboratory Assignment 4: Mitosis and Meiosis. Name: BIOL100 Laboratory Assignment 4: Mitosis and Meiosis Name: Laboratory Objectives After completing this lab topic, you should be able to: 1. Describe the activities of chromosomes and microtubules in the

More information

AP Biology Lab #3: Mitosis Date Period

AP Biology Lab #3: Mitosis Date Period AP Biology Lab #3: Mitosis Name Date Period Introduction and Overview All new cells come from preexisting cells. New cells are formed by the process of cell division which involves both replication of

More information

Cell Cycle and Mitosis Review

Cell Cycle and Mitosis Review Cell Cycle and Mitosis Review This spot that holds the 2 chromatid copies together is called a The phase of the cell cycle in which cells stop dividing all together. Cell division in bacteria cells is

More information

Mitosis and Meiosis BRING YOUR TEXT TO LAB!

Mitosis and Meiosis BRING YOUR TEXT TO LAB! Mitosis and Meiosis BRING YOUR TEXT TO LAB! Objectives: 1. To begin to understand the mechanics of cellular Reproduction/Life Cycles and how the process underlies inheritance. 2. To simulate the movement

More information

The Huntington Library, Art Collections, and Botanical Gardens

The Huntington Library, Art Collections, and Botanical Gardens The Huntington Library, Art Collections, and Botanical Gardens Rooting for Mitosis Overview Students will fix, stain, and make slides of onion root tips. These slides will be examined for the presence

More information

LAB EXERCISE: Mitosis and Meiosis

LAB EXERCISE: Mitosis and Meiosis LAB EXERCISE: Mitosis and Meiosis Laboratory Objectives After completing this lab topic, you should be able to: 1. Describe the activities of chromosomes and microtubules in the cell cycle, including all

More information

LABORATORY 2 THE CELL CYCLE AND THE STAGES OF MITOSIS LEARNING OBJECTIVES AFTER COMPLETING THIS LABORATORY, YOU SHOULD BE ABLE TO:

LABORATORY 2 THE CELL CYCLE AND THE STAGES OF MITOSIS LEARNING OBJECTIVES AFTER COMPLETING THIS LABORATORY, YOU SHOULD BE ABLE TO: LABORATORY 2 THE CELL CYCLE AND THE STAGES OF MITOSIS LEARNING OBJECTIVES AFTER COMPLETING THIS LABORATORY, YOU SHOULD BE ABLE TO: 1. Describe the cell cycle. 2. Identify stages of mitosis from prepared

More information

The Cell Cycle: Interphase, Mitosis and Cytokinesis

The Cell Cycle: Interphase, Mitosis and Cytokinesis The Cell Cycle: Interphase, Mitosis and Cytokinesis Introduction: You should be able to: Define interphase, mitosis and cytokinesis Describe the cell cycle Discuss the events and significance of mitosis.

More information

(From the Kerckhoff Laboratories of Biology, California Institute of Technology, Pasadena, and Sacramento State College, Sacramento)

(From the Kerckhoff Laboratories of Biology, California Institute of Technology, Pasadena, and Sacramento State College, Sacramento) THE CYTOCHEMICAL LOCALIZATION OF ASCORBIC ACID IN ROOT TIP CELLS BY WILLIAM A. JENSEN,* PH.D., AND LEROY G. KAVALJ-IAN,$ PH.D. (From the Kerckhoff Laboratories of Biology, California Institute of Technology,

More information

Mitosis and Meiosis. Part I Mitosis

Mitosis and Meiosis. Part I Mitosis Mitosis and Meiosis Name Date Part I Mitosis It was discovered in 1858, by Rudolf Virchow, that new cells can only arise from previously existing cells. This is done in two ways: mitosis and meiosis. Body

More information

LAB 09 Cell Division

LAB 09 Cell Division LAB 09 Cell Division Introduction: One of the characteristics of living things is the ability to replicate and pass on genetic information to the next generation. Cell division in individual bacteria and

More information

Time For Mitosis. Materials. Procedure. Name

Time For Mitosis. Materials. Procedure. Name Time For Mitosis Name Do all phases of mitosis require the same amount of time for completion? This question can be answered by counting the number of onion root tip cells in the four phases of mitosis

More information

Chapter 3. Cell Division. Laboratory Activities Activity 3.1: Mock Mitosis Activity 3.2: Mitosis in Onion Cells Activity 3.

Chapter 3. Cell Division. Laboratory Activities Activity 3.1: Mock Mitosis Activity 3.2: Mitosis in Onion Cells Activity 3. Chapter 3 Cell Division Laboratory Activities Activity 3.1: Mock Mitosis Activity 3.2: Mitosis in Onion Cells Activity 3.3: Mock Meiosis Goals Following this exercise students should be able to Recognize

More information

The Process of Cell Division. Lesson Overview. Lesson Overview. Cell Growth and Development

The Process of Cell Division. Lesson Overview. Lesson Overview. Cell Growth and Development Lesson Overview Cell Growth and Development Chromosomes The genetic information that is passed on from one generation of cells to the next is carried by chromosomes. Every cell must copy its genetic information

More information

Unit 2: Tissues, Organs, and Systems. The Cell Cycle

Unit 2: Tissues, Organs, and Systems. The Cell Cycle Unit 2: Tissues, Organs, and Systems The Cell Cycle Cells All living things are made up of one or more cells. An adult human is made up of approximately 100 trillion cells. Cells are the structural and

More information

CHAPTER 9 CELLULAR REPRODUCTION P. 243-257

CHAPTER 9 CELLULAR REPRODUCTION P. 243-257 CHAPTER 9 CELLULAR REPRODUCTION P. 243-257 SECTION 9-1 CELLULAR GROWTH Page 244 ESSENTIAL QUESTION Why is it beneficial for cells to remain small? MAIN IDEA Cells grow until they reach their size limit,

More information

Chapter 12: The Cell Cycle (Mitosis) Cell division is an integral part of the cell cycle

Chapter 12: The Cell Cycle (Mitosis) Cell division is an integral part of the cell cycle Chapter 12: The Cell Cycle (Mitosis) Cell division is an integral part of the cell cycle Concept 12.1: Cell division results in genetically identical daughter cells Most cell division (mitosis) results

More information

Mitosis. Asexual Reproduction. identical to each other and to the parent cell

Mitosis. Asexual Reproduction. identical to each other and to the parent cell Mitosis & Meiosis Mitosis Asexual Reproduction The end result is 2 cells that are genetically identical to each other and to the parent cell from which they formed Occurs in somatic cells (non-gametes)

More information

Cell Cycle and Mitosis

Cell Cycle and Mitosis Cell Cycle and Mitosis THE CELL CYCLE The cell cycle, or cell-division cycle, is the series of events that take place in a eukaryotic cell between its formation and the moment it replicates itself. These

More information

1. When new cells are formed through the process of mitosis, the number of chromosomes in the new cells

1. When new cells are formed through the process of mitosis, the number of chromosomes in the new cells Cell Growth and Reproduction 1. When new cells are formed through the process of mitosis, the number of chromosomes in the new cells A. is half of that of the parent cell. B. remains the same as in the

More information

Lab 8 Mitosis and Meiosis

Lab 8 Mitosis and Meiosis Lab 8 Mitosis and Meiosis Introduction: All new cells come from previously existing cells. New cells are formed by karyokinesis (the process in cell division that involves replication of the cell s nucleus)

More information

1. Identify each phase of mitosis on the onion root tip and the whitefish blastula. 3. Explain differences in mitosis between plant and animal cells.

1. Identify each phase of mitosis on the onion root tip and the whitefish blastula. 3. Explain differences in mitosis between plant and animal cells. Mitosis Objectives Having completed the lab on mitosis, you should be able to: 1. Identify each phase of mitosis on the onion root tip and the whitefish blastula. 2. Describe the events during each phase

More information

Lab 6. Cellular Reproduction: Mitosis and Meiosis

Lab 6. Cellular Reproduction: Mitosis and Meiosis Lab 6. Cellular Reproduction: Mitosis and Meiosis Cell Division - Mitosis Sexually-reproducing, multicellular organisms begin life as a single cell, the fertilized egg. This cell, the zygote, through the

More information

This phase of mitosis is? This phase of mitosis is? - This phase of mitosis is? This phase of mitosis is? Graphic source:

This phase of mitosis is? This phase of mitosis is? - This phase of mitosis is? This phase of mitosis is? Graphic source: 1 2 This phase of mitosis is? This phase of mitosis is? - 3 4 This phase of mitosis is? This phase of mitosis is? 5 6 What are the stages of mitosis in chronological order? This phase of mitosis is? -Anaphase,

More information

Lab: Mitosis & Meiosis

Lab: Mitosis & Meiosis Bio 101 Name Lab: Mitosis & Meiosis OBJECTIVES To observe the stages of mitosis in prepared slides of whitefish blastula and onion root tips. To gain a better understanding of the process of mitosis in

More information

Cell Division CELL DIVISION. Mitosis. Designation of Number of Chromosomes. Homologous Chromosomes. Meiosis

Cell Division CELL DIVISION. Mitosis. Designation of Number of Chromosomes. Homologous Chromosomes. Meiosis Cell Division CELL DIVISION Anatomy and Physiology Text and Laboratory Workbook, Stephen G. Davenport, Copyright 2006, All Rights Reserved, no part of this publication can be used for any commercial purpose.

More information

growth and tissue repair in multicellular organisms (mitosis)

growth and tissue repair in multicellular organisms (mitosis) Cell division: mitosis and meiosis I. Cell division -- introduction - roles for cell division: reproduction -- unicellular organisms (mitosis) growth and tissue repair in multicellular organisms (mitosis)

More information

Mitosis in Onion Root Tip Cells

Mitosis in Onion Root Tip Cells Mitosis in Onion Root Tip Cells A quick overview of cell division The genetic information of plants, animals and other eukaryotic organisms resides in several (or many) individual DNA molecules, or chromosomes.

More information

Cell Cycle and Mitosis

Cell Cycle and Mitosis Cell Cycle and Mitosis THE CELL CYCLE The cell cycle, or cell-division cycle, is the series of events that take place in a eukaryotic cell between its formation and the moment it replicates itself. These

More information

LAB. MITOSIS AND CANCER

LAB. MITOSIS AND CANCER Period Date LAB. MITOSIS AND CANCER One of the basic tenets of biology is that all new cells come from living cells. New cells are formed by the process of cell division which includes both the division

More information

Cell cycle & Mitosis. Cellular Organization of the Genetic Material 2016-06- 13

Cell cycle & Mitosis. Cellular Organization of the Genetic Material 2016-06- 13 Cell cycle & Mitosis Review In unicellular organisms, division of one cell reproduces the entire organism Multicellular organisms depend on cell division for Development from a fertilized cell Growth Repair

More information

LAB 8 EUKARYOTIC CELL DIVISION: MITOSIS AND MEIOSIS

LAB 8 EUKARYOTIC CELL DIVISION: MITOSIS AND MEIOSIS LAB 8 EUKARYOTIC CELL DIVISION: MITOSIS AND MEIOSIS Los Angeles Mission College Biology 3 Name: Date: INTRODUCTION BINARY FISSION: Prokaryotic cells (bacteria) reproduce asexually by binary fission. Bacterial

More information

Lab 3: Testing Hypotheses about Mitosis

Lab 3: Testing Hypotheses about Mitosis Lab 3: Testing Hypotheses about Mitosis Why do cells divide? Lab today focuses on cellular division, also known as cellular reproduction. To become more familiar with why cells divide, the types of cell

More information

Cellular Reproduction

Cellular Reproduction 9 Cellular Reproduction section 1 Cellular Growth Before You Read Think about the life cycle of a human. On the lines below, write some of the stages that occur in the life cycle of a human. In this section,

More information

Laboratory Observing the Cell Cycle of Onion Root Tip Cells

Laboratory Observing the Cell Cycle of Onion Root Tip Cells Laboratory Observing the Cell Cycle of Onion Root Tip Cells Background: Because of their rapid growth, the cells of the root tips of plants undergo rapid cell division. Ornamental onion root tips cells

More information

Mitosis and Cytokinesis

Mitosis and Cytokinesis B-2.6 Summarize the characteristics of the cell cycle: interphase (called G1, S, G2); the phases of mitosis (called prophase, metaphase, anaphase, and telophase); and plant and animal cytokinesis. The

More information

Look for these related items from Learning Resources :

Look for these related items from Learning Resources : Look for these related items from Learning Resources : LER 1901 Cross Section Plant Cell LER 1902 Cross Section Heart Model LER 1903 Cross Section Brain Model LER 2437 Cross Section Earth Model For a dealer

More information

Lab 10 Mitosis. Background. Mitosis. Prokaryotic fission. Prophase During prophase, the chromatin. Eukaryotic cell division

Lab 10 Mitosis. Background. Mitosis. Prokaryotic fission. Prophase During prophase, the chromatin. Eukaryotic cell division Lab 10 Mitosis Background Reproduction means producing a new organism from an existing organism. The new offspring must receive hereditary information and enough cytoplasmic material to maintain its own

More information

Name Date. Meiosis Worksheet

Name Date. Meiosis Worksheet Name Date Meiosis Worksheet Identifying Processes On the lines provided, order the different stages of meiosis I THROUGH meiosis II, including interphase in the proper sequence. 1. homologous chromosome

More information

Cell Division Mitosis and the Cell Cycle

Cell Division Mitosis and the Cell Cycle Cell Division Mitosis and the Cell Cycle A Chromosome and Sister Chromatids Key Points About Chromosome Structure A chromosome consists of DNA that is wrapped around proteins (histones) and condensed Each

More information

The illustrations below reflect other scientists results in identifying and counting the stages of the onion root tip and the whitefish blastula.

The illustrations below reflect other scientists results in identifying and counting the stages of the onion root tip and the whitefish blastula. Abstract: The purpose of this laboratory experiment was to identify in what stage of mitosis viewed cells were in. The stages of mitosis include prophase, metaphase, anaphase and telophase. Although the

More information

EXPERIMENT #8 CELL DIVISION: MITOSIS & MEIOSIS

EXPERIMENT #8 CELL DIVISION: MITOSIS & MEIOSIS Introduction Cells, the basic unit of life, undergo reproductive acts to maintain the flow of genetic information from parent to offspring. The processes of mitosis and meiosis are cellular events in which

More information

2. Discrete units of hereditary information consisting of duplicated DNA are called.

2. Discrete units of hereditary information consisting of duplicated DNA are called. LAB TOPIC 7 BSC 2010L (Principles of Biology 1 Laboratory, Professor Chiappone) MITOSIS AND MEIOSIS (Investigating Biology, 7 th edition) PRACTICE QUIZ QUESTIONS 1. DNA is found in structures called. (a)

More information

Cell Cycle in Onion Root Tip Cells (IB)

Cell Cycle in Onion Root Tip Cells (IB) Cell Cycle in Onion Root Tip Cells (IB) A quick overview of cell division The genetic information of plants, animals and other eukaryotic organisms resides in several (or many) individual DNA molecules,

More information

Cells, Mitosis-Meiosis, Photosynthesis-Cellular Respiration Notes F

Cells, Mitosis-Meiosis, Photosynthesis-Cellular Respiration Notes F Cells, Mitosis-Meiosis, Photosynthesis-Cellular Respiration Notes F Chromosomes and Mitosis Vocabulary anaphase centromere chromatid chromatin chromosome gene homologous chromosomes metaphase prophase

More information

Cells (ScienceGHSGT1) 1. Which part of the cell provides energy through the process of cellular respiration?

Cells (ScienceGHSGT1) 1. Which part of the cell provides energy through the process of cellular respiration? Name: Date: 1. Which part of the cell provides energy through the process of cellular respiration? A. cell wall B. cytoplasm C. mitochondrion D. cell membrane 2. All cells must have a A. cell membrane.

More information

The Cell Cycle TEACHER NOTES MIDDLE GRADES SCIENCE NSPIRED. Science Objectives. Vocabulary. About the Lesson. TI-Nspire Navigator. Activity Materials

The Cell Cycle TEACHER NOTES MIDDLE GRADES SCIENCE NSPIRED. Science Objectives. Vocabulary. About the Lesson. TI-Nspire Navigator. Activity Materials Science Objectives Students will identify the changes that occur in cells during each phase of mitosis. Students will correlate these changes to the duration of time cells spend in each phase. While looking

More information

Part 1: Mitosis & Cytokinesis

Part 1: Mitosis & Cytokinesis Lab 5 - Bio 160 Name: Part 1: Mitosis & Cytokinesis OBJECTIVES Το observe the stages of mitosis in prepared slides of whitefish blastula and onion root tips. Το gain a better understanding of the process

More information

Cell Growth and Reproduction Module B, Anchor 1

Cell Growth and Reproduction Module B, Anchor 1 Cell Growth and Reproduction Module B, Anchor 1 Key Concepts: - The larger a cell becomes, the more demands the cell places on its DNA. In addition, a larger cell is less efficient in moving nutrients

More information

Worksheet for Morgan/Carter Laboratory #7 Mitosis and Meiosis

Worksheet for Morgan/Carter Laboratory #7 Mitosis and Meiosis Worksheet for Morgan/Carter Laboratory #7 Mitosis and Meiosis Ex. 7-1: MODELING THE CELL CYCLE AND MITOSIS IN AN ANIMAL CELL Lab Study A: Interphase How many pairs of homologous chromosomes are present

More information

NUCLEI OF FIXED CELLS BY DNA POLYMERASE

NUCLEI OF FIXED CELLS BY DNA POLYMERASE INCORPORATION OF NUCLEOTIDES INTO NUCLEI OF FIXED CELLS BY DNA POLYMERASE R. C. VON BORSTEL, D. M. PRESCOTT, and F. J. BOLLUM From the Biology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee.

More information

List the four phases of mitosis in order. Prophase, Metaphase, Anaphase, Telophase

List the four phases of mitosis in order. Prophase, Metaphase, Anaphase, Telophase List the four phases of mitosis in order Prophase, Metaphase, Anaphase, Telophase Identify and briefly describe each of the parts of the cell cycle. G1 phase, cell growth; S phase, DNA replication; G2

More information

Mitosis & Meiosis. Bio 103 Lecture Dr. Largen

Mitosis & Meiosis. Bio 103 Lecture Dr. Largen 1 Mitosis & Meiosis Bio 103 Lecture Dr. Largen 2 Cells arise only from preexisting cells all cells come from cells perpetuation of life based on reproduction of cells referred to as cell division 3 Cells

More information

CHROMOSOME STRUCTURE CHROMOSOME NUMBERS

CHROMOSOME STRUCTURE CHROMOSOME NUMBERS CHROMOSOME STRUCTURE 1. During nuclear division, the DNA (as chromatin) in a Eukaryotic cell's nucleus is coiled into very tight compact structures called chromosomes. These are rod-shaped structures made

More information

Cell Division Mitosis and Meiosis

Cell Division Mitosis and Meiosis Cell Division Mitosis and Meiosis students will describe the processes of mitosis and meiosis o define and explain the significance of chromosome number in somatic and sex cells o explain the events of

More information

4.1 Cell Division and Genetic Material pg The Cell Theory is a central idea to Biology and it evolved in the 1800 s. The Cell Theory States:

4.1 Cell Division and Genetic Material pg The Cell Theory is a central idea to Biology and it evolved in the 1800 s. The Cell Theory States: 4.1 Cell Division and Genetic Material pg. 160 The Cell Theory is a central idea to Biology and it evolved in the 1800 s. The Cell Theory States: 1. All living things are composed of one or more cells.

More information

Chapter 12: The Cell Cycle

Chapter 12: The Cell Cycle Name Period Chapter 12: The Cell Cycle Overview: 1. What are the three key roles of cell division? State each role, and give an example. Key Role Reproduction Growth and development Tissue removal Example

More information

Chapter 10 Cell Growth and Division

Chapter 10 Cell Growth and Division Chapter Outline Chapter 10 Cell Growth and Division Section 1: Cell Reproduction KEY IDEAS > Why do cells divide? > How is DNA packaged into the nucleus? > How do cells prepare for division? WHY CELLS

More information

MITOSIS AND MEISOSIS

MITOSIS AND MEISOSIS MITOSIS AND MEISOSIS The two labs dealing with cell division are juxtaposed as they are closely related and yet have some significant differences. Learning to compare and contrast mechanisms is very important

More information

MITOSIS IN ONION ROOT TIP CELLS: AN INTRODUCTION TO LIGHT MICROSCOPY

MITOSIS IN ONION ROOT TIP CELLS: AN INTRODUCTION TO LIGHT MICROSCOPY MITOSIS IN ONION ROOT TIP CELLS: AN INTRODUCTION TO LIGHT MICROSCOPY Adapted from Foundations of Biology I; Lab 6 Introduction to Microscopy Dr. John Robertson, Westminster College Biology Department,

More information

Pre-lab Homework Lab 2: Mitosis and the Cell Cycle

Pre-lab Homework Lab 2: Mitosis and the Cell Cycle Pre-lab Homework Lab 2: Mitosis and the Cell Cycle Name: Date/Lab time: 1. Label the figure with the following phases of the cell cycle (note the position of interphase and mitosis): G 1 G 2 S Anaphase

More information

If and when cancer cells stop dividing, they do so at random points, not at the normal checkpoints in the cell cycle.

If and when cancer cells stop dividing, they do so at random points, not at the normal checkpoints in the cell cycle. Cancer cells have escaped from cell cycle controls Cancer cells divide excessively and invade other tissues because they are free of the body s control mechanisms. Cancer cells do not stop dividing when

More information

Part II: Process of Meiosis

Part II: Process of Meiosis Part II: Process of Meiosis The process of eukaryotic cell division during which the number of chromosomes is cut in half. Involves Karyokinesis Sequence of two divisions Start with one nucleus End up

More information

Meiosis is a special form of cell division.

Meiosis is a special form of cell division. Page 1 of 6 KEY CONCEPT Meiosis is a special form of cell division. BEFORE, you learned Mitosis produces two genetically identical cells In sexual reproduction, offspring inherit traits from both parents

More information

CELL DIVISION: MITOSIS AND MEIOSIS

CELL DIVISION: MITOSIS AND MEIOSIS CELL DIVISION: MITOSIS AND MEIOSIS How do eukaryotic cells divide to produce genetically identical cells or to produce gametes with half the normal DNA? BACKGROUND One of the characteristics of living

More information

Eukaryotic Cells and the Cell Cycle

Eukaryotic Cells and the Cell Cycle Eukaryotic Cells and the Cell Cycle Mitosis, Meiosis, & Fertilization Learning Goals: After completing this laboratory exercise you will be able to: 1. Identify the stages of the cell cycle. 2. Follow

More information

Cell Cycle and Cell Division

Cell Cycle and Cell Division Very Short Answer Type Questions Cell Cycle and Cell Division 1. Between a prokaryote and a eukaryote, which cell has a shorter cell division time? A: Prokaryotes have shorter cell division time. 2. Among

More information

SELF-PREPARATION FOR THE BIOLOGY ASSESSMENT TEST MODULE 5: MITOSIS AND MEIOSIS

SELF-PREPARATION FOR THE BIOLOGY ASSESSMENT TEST MODULE 5: MITOSIS AND MEIOSIS SELF-PREPARATION FOR THE BIOLOGY ASSESSMENT TEST MODULE 5: MITOSIS AND MEIOSIS Mitosis and meiosis: Two types of eukaryotic cell division According to the Cell Theory, new cells are created by the division

More information

Cellular Reproduction In Eukaryotic Cells

Cellular Reproduction In Eukaryotic Cells Cellular Reproduction In Eukaryotic Cells OBJECTIVE: By the end of the exercise you should be able to: 1. Describe the events associated with the cell cycle. 2. Describe the events associated with mitosis.

More information

CELL CYCLE AND CELL DIVISION

CELL CYCLE AND CELL DIVISION 1 CH 10 CELL CYCLE & CELL DIVISION CELL CYCLE AND CELL DIVISION Growth and reproduction are characteristics of living cells and organisms. Cell Cycle The sequence of events by which a cell duplicates its

More information

Appendix C DNA Replication & Mitosis

Appendix C DNA Replication & Mitosis K.Muma Bio 6 Appendix C DNA Replication & Mitosis Study Objectives: Appendix C: DNA replication and Mitosis 1. Describe the structure of DNA and where it is found. 2. Explain complimentary base pairing:

More information

Types of cell divisions - Mitosis and Meiosis. MITOSIS or Equational Division

Types of cell divisions - Mitosis and Meiosis. MITOSIS or Equational Division CELL DIVISION In multicellular organisms, growth is caused due to the cumulative effect of cell division cell elongation and cell differentiation Cell division is essential for growth and reproduction

More information

Addition by Division TEACHER NOTES SCIENCE NSPIRED

Addition by Division TEACHER NOTES SCIENCE NSPIRED Science Objectives Students will identify the changes that occur in cells during each phase of the cell cycle. Students will correlate these changes to the duration of time cells spend in each phase. While

More information

CHAPTER 10 CELL CYCLE AND CELL DIVISION

CHAPTER 10 CELL CYCLE AND CELL DIVISION CHAPTER 10 CELL CYCLE AND CELL DIVISION Cell division is an inherent property of living organisms. It is a process in which cells reproduce their own kind. The growth, differentiation, reproduction and

More information

The cell cycle, mitosis and meiosis

The cell cycle, mitosis and meiosis The cell cycle, mitosis and meiosis Learning objective This learning material is about the life cycle of a cell and the series of stages by which genetic materials are duplicated and partitioned to produce

More information

Mitosis How do living things grow and repair themselves?

Mitosis How do living things grow and repair themselves? Mitosis How do living things grow and repair themselves? Why? Living things must grow and develop. At times they suffer injuries or damage, or cells simply wear out. New cells must be formed for the living

More information

EXTRACTION OF DNA FROM CALF THYMUS CELLS Revised 2/1/96 Introduction

EXTRACTION OF DNA FROM CALF THYMUS CELLS Revised 2/1/96 Introduction Revised 2/1/96 Introduction Cells may be classified into two primary types depending on whether they have a discrete nucleus (eukaryotic) or do not (prokaryotic). Prokaryotes include bacteria, such as

More information

The Somatic Cell Cycle

The Somatic Cell Cycle The Somatic Cell Cycle Maternal chromosome Diploid Zygote Diploid Zygote Paternal chromosome MITOSIS MITOSIS Maternal chromosome Diploid organism Diploid organism Paternal chromosome Int terpha ase The

More information

Sample Questions for Exam 3

Sample Questions for Exam 3 Sample Questions for Exam 3 1. All of the following occur during prometaphase of mitosis in animal cells except a. the centrioles move toward opposite poles. b. the nucleolus can no longer be seen. c.

More information

Chapter 8 Cell division. Review

Chapter 8 Cell division. Review Chapter 8 Cell division Mitosis/Meiosis Review This spot that holds the 2 chromatid copies together is called a centromere The phase of the cell cycle in which cells stop dividing all together. G 0 Cell

More information

Mitosis. How do living things grow and repair themselves? Prophase Metaphase Anaphase Telophase. Centriole

Mitosis. How do living things grow and repair themselves? Prophase Metaphase Anaphase Telophase. Centriole Why? Mitosis How do living things grow and repair themselves? Living things must grow and develop. At times they suffer injuries or damage, or cells simply wear out. New cells must be formed for the organism

More information

1. Why is mitosis alone insufficient for the life cycle of sexually reproducing eukaryotes?

1. Why is mitosis alone insufficient for the life cycle of sexually reproducing eukaryotes? Chapter 13: Meiosis and Sexual Life Cycles 1. Why is mitosis alone insufficient for the life cycle of sexually reproducing eukaryotes? 2. Define: gamete zygote meiosis homologous chromosomes diploid haploid

More information

Mitosis: Student Activity Lesson Plan

Mitosis: Student Activity Lesson Plan : Student Activity Lesson Plan Subject/Strand/Topic: Science Reproduction - Mitosis Grade(s) / Course(s): 9 / SNC 1D, SNC 1P Ontario Expectations: BY1.02, BY1.01 Key Concepts: mitosis, cell division, prophase,

More information

Mitosis. Cellular Reproduction Part I

Mitosis. Cellular Reproduction Part I Mitosis Cellular Reproduction Part I Cells must reproduce, the cell cycle describes how cells reproduce and what regulates reproduction. All somatic cells (non sex cells) go through the cell cycle. It

More information

Lecture 3 Cell division: mitosis and meiosis

Lecture 3 Cell division: mitosis and meiosis Lecture 3 Cell division: mitosis and meiosis CAMPBELL BIOLOGY Chapter 8 1 The Cell Division Cycle Almost 90% of the cycle is taken up with Interphase during which DNA in the nucleus is replicated Mitosis

More information

Cell Division. Use Target Reading Skills. This section explains how cells grow and divide.

Cell Division. Use Target Reading Skills. This section explains how cells grow and divide. Cell Processes and Energy Name Date Class Cell Processes and Energy Guided Reading and Study Cell Division This section explains how cells grow and divide. Use Target Reading Skills As you read, make a

More information

From DNA to Protein

From DNA to Protein Nucleus Control center of the cell contains the genetic library encoded in the sequences of nucleotides in molecules of DNA code for the amino acid sequences of all proteins determines which specific proteins

More information

Lecture 2: Mitosis and meiosis

Lecture 2: Mitosis and meiosis Lecture 2: Mitosis and meiosis 1. Chromosomes 2. Diploid life cycle 3. Cell cycle 4. Mitosis 5. Meiosis 6. Parallel behavior of genes and chromosomes Basic morphology of chromosomes telomere short arm

More information

List, describe, diagram, and identify the stages of meiosis.

List, describe, diagram, and identify the stages of meiosis. Meiosis and Sexual Life Cycles In this topic we will examine a second type of cell division used by eukaryotic cells: meiosis. In addition, we will see how the 2 types of eukaryotic cell division, mitosis

More information

Advanced Subsidiary Unit 2: Development, Plants and the Environment. Tuesday 19 January 2010 Afternoon Time: 1 hour 30 minutes

Advanced Subsidiary Unit 2: Development, Plants and the Environment. Tuesday 19 January 2010 Afternoon Time: 1 hour 30 minutes Write your name here Surname Other names Edexcel GCE Centre Number Candidate Number Biology Advanced Subsidiary Unit 2: Development, Plants and the Environment Tuesday 19 January 2010 Afternoon Time: 1

More information

Biology Behind the Crime Scene Week 4: Lab #4 Genetics Exercise (Meiosis) and RFLP Analysis of DNA

Biology Behind the Crime Scene Week 4: Lab #4 Genetics Exercise (Meiosis) and RFLP Analysis of DNA Page 1 of 5 Biology Behind the Crime Scene Week 4: Lab #4 Genetics Exercise (Meiosis) and RFLP Analysis of DNA Genetics Exercise: Understanding how meiosis affects genetic inheritance and DNA patterns

More information

CELL PROCESSES AND ENERGY

CELL PROCESSES AND ENERGY CHAPTER 5 CELL PROCESSES AND ENERGY SECTION 5 1 The Cell in Its Environment (pages 158-162) This section tells how things move into and out of cells. The Cell Membrane as Gatekeeper (page 158) 1. The cell

More information

Lecture 7 Mitosis & Meiosis

Lecture 7 Mitosis & Meiosis Lecture 7 Mitosis & Meiosis Cell Division Essential for body growth and tissue repair Interphase G 1 phase Primary cell growth phase S phase DNA replication G 2 phase Microtubule synthesis Mitosis Nuclear

More information

Carbon Hydrogen Oxygen Nitrogen

Carbon Hydrogen Oxygen Nitrogen Concept 1 - Thinking Practice 1. If the following molecules were to undergo a dehydration synthesis reaction, what molecules would result? Circle the parts of each amino acid that will interact and draw

More information

Biology 160 Lab Module 10 Meiosis Activity & Mendelian Genetics

Biology 160 Lab Module 10 Meiosis Activity & Mendelian Genetics Name Biology 160 Lab Module 10 Meiosis Activity & Mendelian Genetics Introduction During your lifetime you have grown from a single celled zygote into an organism made up of trillions of cells. The vast

More information

How Well Do You Know Your Cells?

How Well Do You Know Your Cells? How Well Do You Know Your Cells? Complete each sentence below with words from the box. One word will not be used. cells cell membrane cell walls chloroplasts cytoplasm Hooke Leeuwenhoek mitochondria nucleus

More information

Chapter 8: The Cellular Basis of Reproduction and Inheritance

Chapter 8: The Cellular Basis of Reproduction and Inheritance Chapter 8: The Cellular Basis of Reproduction and Inheritance Introduction Stages of an Organism s Life Cycle: Development: All changes that occur from a fertilized egg or an initial cell to an adult organism.

More information

Lecture 11 The Cell Cycle and Mitosis

Lecture 11 The Cell Cycle and Mitosis Lecture 11 The Cell Cycle and Mitosis In this lecture Cell division Chromosomes The cell cycle Mitosis PPMAT Apoptosis What is cell division? Cells divide in order to reproduce themselves The cell cycle

More information

Biology. Chapter 10/11

Biology. Chapter 10/11 Biology Chapter 10/11 Interest grabber NOTEBOOK #1 Getting Through Materials move through cells by diffusion. Oxygen and food move into cells, while waste products move out of cells. How does the size

More information