2 THINK ABOUT IT As geneticists in the early 1900s applied Mendel s laws, they wondered where genes might be located. They expected genes to be carried on structures inside the cell, but which structures? What cellular processes could account for what they observed?
3 Chromosome Number How many sets of genes do multicellular organisms inherit?
4 Chromosome Number How many sets of genes do multicellular organisms inherit? The diploid cells of most adult organisms contain two complete sets of inherited chromosomes and two complete sets of genes.
5 Chromosome Number Chromosomes those strands of DNA and protein inside the cell nucleus are the carriers of genes. The genes are located in specific positions on chromosomes.
7 Diploid Cells A body cell in an adult fruit fly has eight chromosomes, as shown in the figure. Four of the chromosomes come from its male parent, and four come from its female parent.
8 Diploid Cells Two sets of chromosomes are homologous, meaning that each of the four chromosomes from the male parent has a corresponding chromosome from the female parent.
9 Diploid Cells A cell that contains both sets of homologous chromosomes is diploid, meaning two sets. The diploid number of chromosomes is sometimes represented by the symbol 2N.
10 Diploid Cells For the fruit fly, the diploid number is 8, which can be written as 2N = 8, where N represents twice the number of chromosomes in a sperm or egg cell. Sperm or egg cells are called gametes. 2N = 8
11 Haploid Cells Some cells contain only a single set of chromosomes, and therefore a single set of genes. Such cells are haploid, meaning one set.
12 Haploid Cells The gametes of sexually reproducing organisms are haploid. For fruit fly gametes, the haploid number is 4, which can be written as N = 4. N=4
13 Diploid vs. Haploid Diploid Haploid 2N = 8 N = 4
14 Phases of What events occur during each phase of meiosis?
15 Phases of is a process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.
16 Phases of usually involves two distinct divisions, called meiosis I and meiosis II. By the end of meiosis II, the diploid cell becomes four haploid cells.
17 I Just prior to meiosis I, the cell undergoes a round of chromosome replication called interphase I.
18 I Each replicated chromosome consists of two identical chromatids joined at the center.
19 Prophase I The cells begin to divide, and the chromosomes pair up, forming a structure called a tetrad, which contains four chromatids.
20 Prophase I As homologous chromosomes pair up and form tetrads, they undergo a process called crossing-over. First, the chromatids of the homologous chromosomes cross over one another.
21 Prophase I Then, the crossed sections of the chromatids are exchanged. Crossing-over is important because it produces new combinations of alleles in the cell. This creates
22 Metaphase I As prophase I ends, a spindle forms and attaches to each tetrad. During metaphase I of meiosis, paired homologous chromosomes line up across the center of the cell.
23 Anaphase I During anaphase I, spindle fibers pull each homologous chromosome pair toward opposite ends of the cell. When anaphase I is complete, the separated chromosomes cluster at opposite ends of the cell.
24 Telophase I and Cytokinesis During telophase I, a nuclear membrane forms around each cluster of chromosomes. Cytokinesis follows telophase I, forming two new cells.
25 I I results in two cells, called daughter cells, each of which has four chromatids, as it would after mitosis.
26 I Because each pair of homologous chromosomes was separated, neither daughter cell has the two complete sets of chromosomes that it would have in a diploid cell.
27 I The two cells produced by meiosis I have sets of chromosomes and alleles that are different from each other and from the diploid cell that entered meiosis I.
28 II The two cells produced by meiosis I now enter a second meiotic division. Unlike the first division, neither cell goes through a round of chromosome replication before entering meiosis II.
29 Prophase II As the cells enter prophase II, their chromosomes each consisting of two chromatids become visible. The chromosomes do not pair to form tetrads, because the homologous pairs were already separated during meiosis I.
30 Metaphase II During metaphase of meiosis II, chromosomes line up in the center of each cell.
31 Anaphase II As the cell enters anaphase, the paired chromatids separate.
32 Telophase II, and Cytokinesis In the example shown here, each of the four daughter cells produced in meiosis II receives two chromatids.
33 Telophase II, and Cytokinesis These four daughter cells now contain the haploid number (N) just two chromosomes each. Haploid N=2 Animation Diploid 2N=4
34 Gametes to Zygotes The haploid cells produced by meiosis II are gametes.
35 Gametes to Zygotes In male animals, these gametes are called sperm. In some plants, pollen grains contain haploid sperm cells. In female animals, generally only one of the cells produced by meiosis is involved in reproduction. The female gamete is called an egg in animals and an egg cell in some plants.
36 Gametes to Zygotes Fertilization the fusion of male and female gametes generates new combinations of alleles in a zygote. The zygote undergoes cell division by mitosis and eventually forms a new organism.
37 Gametes to Zygotes
38 Comparing and Mitosis How is meiosis different from mitosis?
39 Comparing and Mitosis How is meiosis different from mitosis? In mitosis, when the two sets of genetic material separate, each daughter cell receives one complete set of chromosomes. In meiosis, homologous chromosomes line up and then move to separate daughter cells.
40 Comparing and Mitosis How is meiosis different from mitosis? Mitosis does not normally change the chromosome number of the original cell. This is not the case for meiosis, which reduces the chromosome number by half.
41 Comparing and Mitosis How is meiosis different from mitosis? Mitosis results in the production of two genetically identical diploid cells, whereas meiosis produces four genetically different haploid cells.
42 Comparing and Mitosis Mitosis is a form of asexual reproduction, whereas meiosis is an early step in sexual reproduction. There are three other ways in which these two processes differ.
43 Replication and Separation of Genetic Material In mitosis, when the two sets of genetic material separate, each daughter cell receives one complete set of chromosomes.
44 Replication and Separation of Genetic Material In meiosis, homologous chromosomes line up and then move to separate daughter cells. As a result, the two alleles for each gene segregate from each other and end up in different cells.
45 Replication and Separation of Genetic Material The sorting and recombination of genes in meiosis result in a greater variety of possible gene combinations than could result from mitosis.
46 Changes in Chromosome Number Mitosis does not normally change the chromosome number of the original cell. reduces the chromosome number by half.
47 Changes in Chromosome Number A diploid cell that enters mitosis with four chromosomes will divide to produce two diploid daughter cells, each of which also has four chromosomes.
48 Changes in Chromosome Number On the other hand, a diploid cell that enters meiosis with four chromosomes will pass through two meiotic divisions to produce four haploid gamete cells, each with only two chromosomes.
49 Number of Cell Divisions Mitosis is a single cell division, resulting in the production of two genetically identical diploid daughter cells.
50 Number of Cell Divisions requires two rounds of cell division, and, in most organisms, produces a total of four genetically different haploid daughter cells.
Notes THINK ABOUT IT As geneticists in the early 1900s applied Mendel s laws, they wondered where genes might be located. They expected genes to be carried on structures inside the cell, but which structures?
11.4 As geneticists in the early 1900s applied Mendel s laws, they wondered where genes might be located. They expected genes to be carried on structures inside the cell, but which structures? What cellular
Lesson Overview 11.4 Meiosis THINK ABOUT IT As geneticists in the early 1900s applied Mendel s laws, they wondered where genes might be located. They expected genes to be carried on structures inside the
11-4 Meiosis 1 of 35 Each organism must inherit a single copy of every gene from each of its parents. Gametes are formed by a process that separates the two sets of genes so that each gamete ends up with
9-4 Meiosis 11-4 Meiosis 1 of 35 11-4 Meiosis Each organism must inherit a single copy of every gene from each of its parents. Gametes are formed by a process that separates the two sets of genes so that
Meiosis 1of 35 Each organism must inherit a single copy of every gene from each of its parents. Gametes are formed by a process that separates the two sets of genes so that each gamete ends up with just
Each organism must inherit a single copy of every gene from each of its parents. Gametes are formed by a process that separates the two sets of genes so that each gamete ends up with just one set. Chromosome
11.4 Chromosomes strands of DNA and protein contain the genes. genes are located in specific positions on chromosomes. Humans receive a set (23) of chromosomes from each parent. 23 chromosomes from mom
biology 1 of 35 Do Now: Turn in mitosis worksheet Write down your homework http://www.richannel.org/collection s/2013/chromosome#/chromosome -2 http://www.richannel.org/collection s/2013/chromosome#/chromosome
11.4 Question #1 What must occur in order for Mendel s principles to hold true? An organism with two parents must inherit a single copy of every gene from each parent When that organism produces gametes,
Sexual Reproduction Recall that asexual reproduction involves only one parent cell. This parent cell divides to produce two daughter cells that are genetically identical to the parent. Sexual reproduction,
Parents can produce many types of offspring Families will have resemblances, but no two are exactly alike. Why is that? Meiosis and Genetic Linkage Objectives Recognize the significance of meiosis to sexual
Cell division / Asexual reproduction Mitosis produces cells with same information identical daughter cells exact copies clones same amount of DNA same number of chromosomes same genetic information Asexual
A. Meiosis Main Idea: Meiosis produces haploid gametes. Key Concept: Asexual reproduction involves one parent and produces offspring that are genetically identical to each other and to the parent. Sexual
Meiosis Section 8-3 Meiosis process of nuclear division that reduces the number of chromosomes in new cells to half the number in the original cell For example, in humans, meiosis produces haploid reproductive
Sexual Reproduction and Meiosis Chapter 11 1 Sexual life cycle Made up of meiosis and fertilization Diploid cells Somatic cells of adults have 2 sets of chromosomes Haploid cells Gametes (egg and sperm)
Sexual Reproduction ( Cell Division ) - Chromosome # s somatic cells: all the cells in the body except for specialized sex cells each somatic cell has a specific # of chromosomes - ( humans have 46, 23
Mitosis & Meiosis SC.912.L.16.17 Compare and contrast mitosis and meiosis and relate to the processes of sexual and asexual reproduction and their consequences for genetic variation. 1. Students will describe
MEIOSIS DR. A. TARAB DEPT. OF BIOCHEMISTRY HKMU Meiosis is a special type of cell division necessary for sexual reproduction in eukaryotes such as animals, plants and fungi The number of sets of chromosomes
Section 1: produces haploid gametes. K What I Know W What I Want to Find Out L What I Learned Essential Questions How does the reduction in chromosome number occur during meiosis? What are the stages of
Meiosis and Sexual Reproduction Chapter 11 Reproduction Section 1 Reproduction Key Idea: An individual formed by asexual reproduction is genetically identical to its parent. Asexual Reproduction In asexual
Meiosis and Life Cycles - 1 We have just finished looking at the process of mitosis, a process that produces cells genetically identical to the original cell. Mitosis ensures that each cell of an organism
Almost all human cells contain 46 chromosomes, and are diploid (2n). Q: If a sperm cell has 46 chromosomes (2n) & an egg cell has 46 chromosomes (2n), when they combine during fertilization, how many chromosomes
Human Heredity Chapter 2 Chromosomes, Mitosis, and Meiosis 2:1 Chromosomes DNA Genes Chromatin Chromosomes CHROMATIN: nuclear material in non-dividing cell, composed of DNA/protein in thin uncoiled strands
Reproduction & Cell Types TYPES OF REPRODUCTION Asexual Relies on MITOSIS All of the parent s DNA goes to the offspring Sexual Relies on MEIOSIS Used to create sex cells TYPES OF CELLS Body Cells Includes
1. From where do new cells arise? Mitosis & Meiosis PPT Questions 2. Why does the body constantly make new cells? 3. Is cell division the same in all cells? Explain. 4. Why must each new cell get a complete
Honors Biology Test Chapter 8 Mitosis and Meiosis 1. In mitosis, if a parent cell has 16 chromosomes, each daughter cell will have how many chromosomes? a. 64 b. 32 c. 16 d. 8 e. 4 2. Chromatids that are
Name: Date: Period: DNA (Deoxyribonucleic Acid) is the chemical inside the nucleus of cells that contains hereditary information. DNA is shaped like a double helix/twisted ladder. The sides of the ladder
The Cell Cycle & Cell Division http://www.nobel.se/medicine/laureates/2001/press.html The Cell Cycle Animated Cycle http://www.cellsalive.com/cell_cycle.htm MITOSIS Mitosis The process of cell division
SEXUAL REPRODUCTION & MEIOSIS Living organisms are distinguished by their ability to reproduce their own kind. Offspring resemble their parents more than they do less closely related individuals of the
Cell Cycle (mitosis and meiosis) Test Review Name: Chapter 10 1. What problems are caused when a cell becomes too large? When a cell becomes too large the cell is strained and has a hard time moving enough
What is mitosis? -Process in which a cell divides, creating TWO complete Sets of the original cell with the same EXACT genetic Material (DNA) Cell Division Produces CLONES with the same # of chromosomes
Meiosis Meiosis is the type of cell division for that produces the cells ( ) which are also known as gametes. Two important characteristics of meiosis is that it reduces the number of chromosomes to half
MEIOSIS CHAPTER 13 CENTRAL DOGMA OF BIOLOGY DNA RNA Protein OFFSPRING ACQUIRE GENES FROM PARENTS Genes are segments of DNA that program specific traits. Genetic info is transmitted as specific sequences
MEIOSIS LAB INTRODUCTION Meiosis involves two successive nuclear divisions that produce four haploid cells. Meiosis I is the reduction division. It is this first division that reduces the chromosome number
Chapter 13: Meiosis & Sexual Life Cycles What you must know The difference between asexual and sexual reproduction. The role of meiosis and fertilization in sexually reproducing organisms. The importance
Biology Unit 6 Chromosomes and Mitosis 6:1 Chromosomes DNA GENES CHROMATIN/CHROMOSOMES CHROMOSOMES/CHROMATIN are made of units called GENES. GENES are made of a compound called deoxyribonucleic acid or
Chapter 11 Meiosis and Sexual S Section 1: S Gamete: Haploid reproductive cell that unites with another haploid reproductive cell to form a zygote. S Zygote: The cell that results from the fusion of gametes
Chapter 13: Meiosis & Sexual Life Cycles What you must know The difference between asexual and sexual reproduction. The role of meiosis and fertilization in sexually reproducing organisms. The importance
The Cell Cycle Cells divide by Mitosis or Meiosis. Mitosis allows the organism to replace cells that have died or aren't working, and is how living things grow. It makes an exact copy of the parent cell.
CHAPTER 6 Chromosomes and Meiosis CHROMOSOMES DNA (deoxyribonucleic acid) is a long, thin molecule that directs cellular functions and heredity. DNA contains information that is encoded in segments called
MEIOSIS Meiosis The form of cell division by which gametes, with half the regular number of chromosomes, are produced. diploid (2n) haploid (n) (complete set of chromosomes) (half the regular number of
MEIOSIS You have body cells and gametes Body cells are known as somatic cells. Germ cells develop into gametes or sex cells. Germ cells are located in the ovaries and testes. Gametes are sex cells: egg
Chapter 13: Meiosis and Sexual Life Cycles Overview: Hereditary Similarity and Variation Living organisms Are distinguished by their ability to reproduce their own kind Biology, 7 th Edition Neil Campbell
For a species to survive, it must REPRODUCE! Ch 13 NOTES Meiosis Genetics Terminology: Autosomes Somatic cell Gamete Karyotype Homologous chromosomes Meiosis Sex chromosomes Diploid Haploid Zygote Synapsis
Chapter 11 INTRODUCTION TO GENETICS 11-1 The Work of Gregor Mendel I. Gregor Mendel A. Studied pea plants 1. Reproduce sexually (have two sex cells = gametes) 2. Uniting of male and female gametes = Fertilization
Name: Bio AP Lab: Cell Division B: Mitosis & Meiosis (Modified from AP Biology Investigative Labs) BACKGROUND: One of the characteristics of living things is the ability to replicate and pass on genetic
CELL GROWTH AND DIVISION Chapter 10 Cell division = The formation of 2 daughter cells from a single parent cell Increases ratio of surface area to volume for each cell Allows for more efficient exchange
Meiosis Bởi: OpenStaxCollege Sexual reproduction requires fertilization, a union of two cells from two individual organisms. If those two cells each contain one set of chromosomes, then the resulting cell
Chromosomes and Meiosis Specialized cells in the body Chromosomes 2 types: Chapter 6: Mendel and Meiosis Meiosis Gamete Production Lecture Guide (body cells) Makes up your DNA in your body cells passed
Name: Aim 35: What is Meiosis? Date: I. What is Meiosis? What is Meiosis? Which organisms undergo Meiosis? Where does Meiosis occur? What does Meiosis produce? What is Meiosis also known as? 1. The process
5.3 Reproduction and Meiosis Lesson Objectives Compare and contrast asexual and sexual reproduction. Give an overview of sexual reproduction, and outline the phases of meiosis. Explain why sexual reproduction
Overview of Meiosis Meiosis is a form of cell division that leads to the production of gametes. Gametes: egg cells and sperm cells (reproductive) -contain half the number of chromosomes of an adult body
Meiosis & Sexual Reproduction 2007-2008 Cell division / Asexual reproduction Mitosis produce cells with same information identical daughter cells exact copies clones same amount of DNA same number of chromosomes
11-1 The 11-1 Work of Gregor Mendel The Work of Gregor Mendel is the scientific study of. Gregor Mendel was an Austrian monk. He is considered the of genetics. Mendel carried out his work with ordinary
Unit 6 : Meiosis & Sexual Reproduction 2006-2007 Cell division / Asexual reproduction Mitosis produce cells with same information identical daughter cells exact copies clones same number of chromosomes
10 Sexual Reproduction and Genetics section 1 Meiosis Before You Read Think about the traits that make people unique. Some people are tall, while others are short. People can have brown, blue, or green
What is the mechanism behind sexual reproduction? Sexual reproduction relies on the formation of egg and sperm; these structures are referred to as gametes. The egg and sperm unite during the process of
Match the stages of mitosis to their descriptions and pictures. 1. Nuclear membrane disappears and chromosomes condense 2. Nuclear membrane reappears and cells begin to fully separate Bell Ringer 02/02/15
MEIOSIS MEIOSIS KEY CONCEPT Gametes have half the number of chromosomes that body cells have. MEIOSIS : CELL TYPES You have Body cells and Gametes Body cells are also called somatic cells. Germ cells develop
Topic 8 Mitosis & Meiosis Ch.12 & 13 The Eukaryotic Genome pp. 244-245,268-269 Genome All of the genes in a cell. Eukaryotic cells contain their DNA in long linear pieces. In prokaryotic cells, there is
!! www.clutchprep.com CONCEPT: SEXUAL REPRODUCTION Meiosis is a special type of cell division that occurs as part of the sexual life cycle of eukaryotes Sexual reproduction parents donate a unique mixture
3.1 Meiosis CHAPTER 3 VOCABULARY (for now) VOCABULARY WORD VOCABULARY WORD diploid number Independent assortment haploid number gametes homologous chromosomes zygote genetic diversity Crossing over Sexual
NAME: OPTION GROUP: CELL DIVISION MEIOSIS WORKBOOK 1 STUDY CHECKLIST AND ASSESSMENT OBJECTIVES Instructions Regular revision throughout the year is essential. It s vital you keep a track of what you understand
Meiosis What therefore God hath joined together, let not man put asunder Mark 10:6-9 Stage Table 1 Meiosis (Without Crossover Event) # Chromosomes Per Cell Prophase I 4 Metaphase I 4 Anaphase I 4 Telophase
Note-taking Workbook Meiosis and Sexual Reproduction Section: Reproduction ASEXUAL REPRODUCTION Key Idea: An individual formed by asexual reproduction is to its parent. Additional notes about Asexual Reproduction:
MEIOSIS, THE BASIS OF SEXUAL REPRODUCTION Why do kids look different from the parents? How are they similar to their parents? Why aren t brothers or sisters more alike? Meiosis A process where the number
Introduction Ch. 13 Meiosis & Sexual Life Cycles 2004-05 Living organisms are distinguished by their ability to reproduce their own kind. -Offspring resemble their parents more than they do less closely
11.4 Meiosis Vocabulary: Homologous Diploid Haploid Meiosis Crossing-over Tetrad Key Concept: What happens during the process of meiosis? How is MEIOSIS different than mitosis? Blast from the past What
Outline for today s lecture (Ch. 13) Sexual and asexual life cycles Meiosis Origins of Genetic Variation Independent assortment Crossing over ( recombination ) Heredity Transmission of traits between generations
M-Phase part 2 Meiosis and Cytokinesis Meiosis: A special type of cell division that produces gametes. Cell division that occurs in sex organs. 2 successive nuclear divisions Genetic mistakes (gene and
The 4 phases of mitosis Animal cells divide their cytoplasm by forming? Bacteria, Paramecium, Amoeba, etc. reproduce by... Cell which after division is identical to the original is called a Prophase, Metaphase,
Chapter 13 Meiosis and Sexual Life Cycles PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from
Meiosis and Sexual Reproduction Chapter 10 Outline Reduction in Chromosome Number Homologous Pairs Meiosis Overview Genetic Recombination Crossing-Over Independent Assortment Fertilization Meiosis I Meiosis
Chapter 6: Cell Growth and Reproduction Lesson 6.3: Meiosis and Reproduction One parent or two? That is the main difference between sexual and asexual reproduction. Sexual reproduction just means combining
BIOLOGY 111 CHAPTER 5: Chromosomes and Inheritance Chromosomes and Inheritance Learning Outcomes 5.1 Differentiate between sexual and asexual reproduction in terms of the genetic variation of the offspring.
Sexual Reproduction Science 9- Mr. Klasz Why sexual reproduction? Imagine a world where everyone was IDENTICAL. If we reproduced asexually, that would be our world Boring! Asexual Reproduction vs. Sexual
Big Ideas 3.A.2: In eukaryotes, heritable information is passed to the next generation via processes that include the cell cycle and mitosis or meiosis plus fertilization. CHAPTER 13 MEIOSIS AND SEXUAL
Visualizing Meiosis Poster Illustrated Teacher's Guide #35-1140 Paper #35-1141 Laminated Background Meiosis Basics Organisms with cells that contain a nucleus are called eukaryotes. The nucleus contains