The document provides an overview of meiosis. It explains that meiosis involves two cell divisions that reduce the chromosome number by half, resulting in four haploid cells. This differs from mitosis, which produces two genetically identical diploid cells. Specifically, meiosis involves homologous chromosomes separating and recombining during prophase I, then separating sister chromatids during meiosis II. This increases genetic variation in the gametes compared to mitosis.
This document summarizes key concepts about animal form and function including:
- The relationship between anatomy, physiology, and convergent evolution in different environments.
- How animals exchange with their environment through features like a jackrabbit's large ears.
- The hierarchical organization of body plans from tissues to organ systems.
- The roles of different tissue types including epithelial, connective, and signaling between cells via hormones or neurons.
- Homeostasis and how animals regulate or conform to environmental variables through feedback control and circadian rhythms.
- Thermoregulation differences between endothermic and ectothermic animals.
- Circulatory and metabolic adaptations that allow energy conservation like torpor and hibernation.
Isotopes are variations of chemical elements that have the same number of protons but different numbers of neutrons. We identify isotopes based on their mass, which is the sum of protons and neutrons. Carbon has three main isotopes: 12C with 6 protons and 6 neutrons; 13C with 6 protons and 7 neutrons; and 14C with 6 protons and 8 neutrons. Isotopes are identified by their distinct masses, which are measured using an isotope ratio mass spectrometer.
Biology - Chp 11 - Introduction To Genetics - PowerPointMel Anthony Pepito
Gregor Mendel's experiments with pea plants in the mid-1800s laid the groundwork for genetics as a science. Through his work, Mendel discovered that traits are passed from parents to offspring through discrete factors that he called genes. He also described the principles of dominance, segregation, and independent assortment. Later, it was discovered that genes are located on chromosomes within cells and are passed from parents to offspring through the cellular process of meiosis. Meiosis results in gametes with half the normal chromosome number, allowing each parent to contribute one set of chromosomes to offspring.
1. animal form and function. animal form and function. animal form and functionArosek Padhi
This document discusses animal form and function at different levels of biological organization. It covers topics like anatomy, physiology, bioenergetics, homeostasis, thermoregulation, and adaptations like torpor and acclimatization. The key points are:
1) Animal form is shaped by natural selection to fit its function and environment over many generations. Its structure at different levels from cells to organ systems allows it to interact with its environment.
2) Bioenergetics examines how animals obtain and use energy from food. Having the right surface area to volume ratio and internal structures allows efficient exchange of materials in multicellular organisms.
3) Homeostasis and thermoregulation allow animals to maintain stable internal conditions
The document outlines the major theories in the development of atomic theory from ancient Greece to the 20th century. It describes the key contributors including:
Democritus who proposed that all matter is made of basic elements composed of indivisible atoms. John Dalton introduced the modern concept of atoms as basic units of elements that combine in fixed ratios. J.J. Thompson discovered the electron and proposed the plum pudding model where electrons are distributed in a positive charge. Ernest Rutherford discovered the nucleus through alpha particle experiments and proposed atoms have a small, dense positively charged nucleus. Niels Bohr incorporated quantum theory and proposed electrons orbit in fixed shells around the nucleus. Finally, Schrodinger and Heisenberg developed the quantum
Magnesium and chlorine have valence electrons in their highest energy level. Magnesium forms Mg2+ ions by losing two valence electrons to attain the electron configuration of neon. Chlorine forms Cl- ions by gaining one electron to attain the electron configuration of argon. Ions are formed by atoms gaining or losing electrons to achieve a noble gas configuration.
1) Early Earth had a different atmosphere than today and was bombarded by asteroids and comets. 2) Miller-Urey experiments showed how organic molecules could form in early Earth conditions. 3) RNA may have come before DNA and led to early life forms. Photosynthetic bacteria later produced oxygen that changed Earth's atmosphere.
- Atoms are the building blocks of matter and are made up of protons, neutrons, and electrons. The nucleus contains protons and neutrons and accounts for nearly all an atom's mass, while electrons orbit the nucleus.
- The number of protons determines the element and cannot be changed. Neutrons can vary between atoms of the same element, creating isotopes of that element.
- An atom's mass number is the total number of protons and neutrons, while its atomic mass refers to the average mass of all isotopes of that element as found in nature.
This document summarizes key concepts about animal form and function including:
- The relationship between anatomy, physiology, and convergent evolution in different environments.
- How animals exchange with their environment through features like a jackrabbit's large ears.
- The hierarchical organization of body plans from tissues to organ systems.
- The roles of different tissue types including epithelial, connective, and signaling between cells via hormones or neurons.
- Homeostasis and how animals regulate or conform to environmental variables through feedback control and circadian rhythms.
- Thermoregulation differences between endothermic and ectothermic animals.
- Circulatory and metabolic adaptations that allow energy conservation like torpor and hibernation.
Isotopes are variations of chemical elements that have the same number of protons but different numbers of neutrons. We identify isotopes based on their mass, which is the sum of protons and neutrons. Carbon has three main isotopes: 12C with 6 protons and 6 neutrons; 13C with 6 protons and 7 neutrons; and 14C with 6 protons and 8 neutrons. Isotopes are identified by their distinct masses, which are measured using an isotope ratio mass spectrometer.
Biology - Chp 11 - Introduction To Genetics - PowerPointMel Anthony Pepito
Gregor Mendel's experiments with pea plants in the mid-1800s laid the groundwork for genetics as a science. Through his work, Mendel discovered that traits are passed from parents to offspring through discrete factors that he called genes. He also described the principles of dominance, segregation, and independent assortment. Later, it was discovered that genes are located on chromosomes within cells and are passed from parents to offspring through the cellular process of meiosis. Meiosis results in gametes with half the normal chromosome number, allowing each parent to contribute one set of chromosomes to offspring.
1. animal form and function. animal form and function. animal form and functionArosek Padhi
This document discusses animal form and function at different levels of biological organization. It covers topics like anatomy, physiology, bioenergetics, homeostasis, thermoregulation, and adaptations like torpor and acclimatization. The key points are:
1) Animal form is shaped by natural selection to fit its function and environment over many generations. Its structure at different levels from cells to organ systems allows it to interact with its environment.
2) Bioenergetics examines how animals obtain and use energy from food. Having the right surface area to volume ratio and internal structures allows efficient exchange of materials in multicellular organisms.
3) Homeostasis and thermoregulation allow animals to maintain stable internal conditions
The document outlines the major theories in the development of atomic theory from ancient Greece to the 20th century. It describes the key contributors including:
Democritus who proposed that all matter is made of basic elements composed of indivisible atoms. John Dalton introduced the modern concept of atoms as basic units of elements that combine in fixed ratios. J.J. Thompson discovered the electron and proposed the plum pudding model where electrons are distributed in a positive charge. Ernest Rutherford discovered the nucleus through alpha particle experiments and proposed atoms have a small, dense positively charged nucleus. Niels Bohr incorporated quantum theory and proposed electrons orbit in fixed shells around the nucleus. Finally, Schrodinger and Heisenberg developed the quantum
Magnesium and chlorine have valence electrons in their highest energy level. Magnesium forms Mg2+ ions by losing two valence electrons to attain the electron configuration of neon. Chlorine forms Cl- ions by gaining one electron to attain the electron configuration of argon. Ions are formed by atoms gaining or losing electrons to achieve a noble gas configuration.
1) Early Earth had a different atmosphere than today and was bombarded by asteroids and comets. 2) Miller-Urey experiments showed how organic molecules could form in early Earth conditions. 3) RNA may have come before DNA and led to early life forms. Photosynthetic bacteria later produced oxygen that changed Earth's atmosphere.
- Atoms are the building blocks of matter and are made up of protons, neutrons, and electrons. The nucleus contains protons and neutrons and accounts for nearly all an atom's mass, while electrons orbit the nucleus.
- The number of protons determines the element and cannot be changed. Neutrons can vary between atoms of the same element, creating isotopes of that element.
- An atom's mass number is the total number of protons and neutrons, while its atomic mass refers to the average mass of all isotopes of that element as found in nature.
This is a powerpoint presentation that discusses about the topic or lesson: Thomson's Atomic Model. It also includes the history of Joseph John Thomson, characteristics and concepts of Thomson's Atomic Model.
Chemical bonding involves atoms forming stable electronic configurations through gaining, losing or sharing electrons. Ionic bonds form between metals and nonmetals when electrons are transferred, while covalent bonds involve sharing electron pairs between nonmetals to achieve stable octets. Different bond types including ionic, covalent and metallic bonding can be identified based on the participating elements and electron configurations involved.
Rutherford performed an experiment in 1911 where he bombarded a thin gold foil with alpha particles. He observed that:
1) Most alpha particles passed through the foil without deflection.
2) A few particles were deflected by small angles.
3) Very few were deflected back at 180 degrees.
From these observations, Rutherford concluded that:
1) Atoms are mostly empty space.
2) A small, dense nucleus explains the few particles being deflected.
3) The nucleus is much smaller than the atom.
This module will help you gain knowledge about cell: the basic unit of all living matter. It is the unit of structure and function of which all plants and animals are composed. The cell is the smallest unit in the living organism that is capable of integrating the essential life processes. The cell is the key to biology because it is at this level that life truly springs. As you read this, you will learn more about the activities of the cell, the structures and the material of life that fills them. Later on, you will discover what a living matter is made of.
J.J. Thomson discovered electrons in 1897 using a cathode ray tube, which showed that cathode rays were streams of electrons. He proposed the plum pudding model of the atom, which depicted the atom as a ball of positive charge with negative electrons embedded inside. This contradicted Dalton's model of individual solid spheres, leading Thomson to disprove Dalton's model of atomic structure.
This document summarizes several genetic disorders caused by abnormalities in human chromosomes, including trisomies where there is an extra chromosome (such as Trisomy 13, 18, and 21), Turner Syndrome where there is missing X chromosome, and some of the common symptoms and facial features of each condition. It also discusses that genetic disorders affect almost 6% of births worldwide annually and that while many have no known cause, some may result from nondisjunction during meiosis where chromosomes do not separate properly.
There are two main types of cells - prokaryotic and eukaryotic cells. Prokaryotic cells were the earliest form of life and lack a nucleus and organelles. Eukaryotic cells are larger and more complex, with a nucleus that contains DNA organized into chromosomes and membrane-bound organelles. The key differences are that prokaryotes lack a nucleus and organelles while eukaryotes have these structures.
Convection currents are circular movements within liquids and gases caused by differences in density between hotter and cooler parts. Hot liquids are less dense than cold liquids, so hotter material rises while cooler, denser material sinks, creating a continuous cycle of circulation. This convection within Earth's mantle drives plate tectonics, as the rising and sinking of hot and cold mantle material carries lithospheric plates along with it.
Determining Geologic Time Scale using Absolute and Relative Dating Earth Scie...AshKyle2
The document discusses methods for determining the geologic time scale and dating geological features. It describes the four eons the geologic time scale is divided into and explains both relative and absolute dating techniques. Relative dating looks at relationships between geological features, while absolute dating uses measurements of radioactive isotopes in rocks and minerals to calculate their precise ages. Examples provided include William Smith's work identifying distinctive fossil sequences to correlate rock layers and the potassium-argon dating method.
The document summarizes the structure and function of eukaryotic cells and their organelles. It discusses that cells have three main jobs: 1) make energy through cellular respiration and photosynthesis using mitochondria and chloroplasts, 2) make proteins using instructions from DNA and structures like the nucleus, ribosomes, ER and Golgi apparatus, and 3) make more cells through DNA replication and cell division aided by the nucleus and centrioles. The organelles each have specialized structures and functions that allow the cell to carry out these essential life processes.
The document discusses comparative primate anatomy between humans and other primates like chimpanzees. Some key differences noted are:
- Humans have a larger brain size that allows for advanced language and tool-making abilities. In contrast, chimpanzee brains are smaller and lack specialized language areas.
- Human skulls have a higher forehead, smaller teeth, and less protruding jaws compared to chimpanzees.
- Features like opposable thumbs and straight fingers allow humans to develop precision grips for finer tool use than other primates.
- Bipedalism is unique to humans and freed the hands for carrying and making tools.
1. Meiosis is a cell division process that produces gametes, or sex cells, with half the number of chromosomes as the original cell.
2. During meiosis, homologous chromosome pairs separate into different daughter cells through two cell divisions, reducing the chromosome number.
3. The end result of meiosis is four haploid cells each with a single set of chromosomes, whereas mitosis produces two diploid cells with a full set of chromosomes.
Meiosis is a two-step process that results in four haploid cells each containing half the number of chromosomes of the original diploid cell. In the first phase, meiosis I, homologous chromosome pairs separate into two daughter cells. In meiosis II, the daughter cells undergo division again without DNA replication, resulting in four haploid cells each with one set of chromosomes. Meiosis reduces the chromosome number in a cell to produce gametes involved in sexual reproduction, while mitosis replicates chromosomes to produce body cells.
Meiosis is a type of cell division that produces gametes, such as sperm or egg cells, with half the normal number of chromosomes. It involves two rounds of cell division, meiosis I and meiosis II, which result in four haploid daughter cells each containing a single set of chromosomes. During meiosis I, homologous chromosomes pair and separate, reducing the chromosome number by half. Meiosis II then separates the sister chromatids, resulting in four haploid cells that can fuse during fertilization. Meiosis ensures genetic variation between offspring by independent assortment and crossing over of homologous chromosomes.
Meiosis is the process by which germ cells are produced with half the normal number of chromosomes. It involves two rounds of cell division, Meiosis I and Meiosis II. In Meiosis I, homologous chromosomes pair up and crossover occurs, followed by the separation of homologous chromosomes into daughter cells. Meiosis II then separates the sister chromatids, resulting in four haploid cells each with one chromosome from each homologous pair. This ensures genetic variation between offspring. Male meiosis occurs over 64 days in the testes and results in four haploid spermatids from one primary spermatocyte. Female meiosis begins in the fetus but pauses at prophase I until ovulation in adulthood.
Mitosis and meiosis are two types of cell division. Mitosis produces two identical daughter cells through prophase, metaphase, anaphase and telophase. Meiosis produces four haploid cells through two divisions, meiosis I and meiosis II. Meiosis I separates homologous chromosomes and results in two haploid cells. Meiosis II separates sister chromatids to form a total of four haploid cells with only one chromosome from each pair. The key difference is that mitosis replicates somatic cells while meiosis forms gametes needed for sexual reproduction.
The human life cycle involves both mitosis and meiosis. Mitosis occurs during development and tissue repair, producing genetically identical cells. Meiosis occurs during sexual reproduction and reduces the chromosome number from diploid to haploid, generating genetically diverse gametes through independent assortment and crossing over. Fertilization of an egg and sperm fuses their haploid cells to form a diploid zygote, continuing the life cycle.
Meiosis is a two-stage cell division process that produces four haploid cells from one diploid cell. It begins with a single diploid cell containing two sets of duplicated chromosomes. The two stages are meiosis I and meiosis II. In meiosis I, homologous chromosome pairs align and separate, resulting in two haploid cells. Meiosis II then divides the contents of these two cells into four haploid cells, each containing one representative from each chromosome pair. This process ensures genetic diversity in offspring.
Meiosis is a type of cell division that produces gametes, such as eggs and sperm, which contain half the number of chromosomes found in regular body cells. It involves two rounds of cell division without an intervening DNA replication phase. In the first round, homologous chromosomes pair up and may exchange genetic material through crossing over. The homologous chromosomes then separate, reducing the chromosome number. The second round separates the sister chromatids, resulting in four haploid daughter cells. This process ensures genetic variation in offspring through independent assortment and crossing over during meiosis I.
Activity 3-4 March ( Professional Studies)3AKarabo Dichaba
This document describes the process of meiosis. It begins by explaining that human somatic cells are diploid, containing 23 pairs of homologous chromosomes, with one chromosome from each parent. Meiosis is then defined as the process that converts diploid cells to haploid cells. The summary proceeds to outline the key stages of meiosis I and meiosis II, including prophase I where homologous chromosomes pair up, metaphase and anaphase where the chromosomes separate, and telophase where the cell divides. The result of meiosis is four haploid cells, with half the number of chromosomes as the original cell.
Each body cell contains two sets of chromosomes from each parent, making them diploid. During meiosis, germ cells undergo two cell divisions to become haploid, with one set of chromosomes. Meiosis occurs through prophase I, metaphase I, anaphase I and telophase I, followed by Meiosis II which separates sister chromatids. In males, spermatogenesis takes 64 days from spermatogonia to spermatozoa through meiosis and spermiogenesis. In females, oogenesis begins in the fetus but pauses at prophase I until ovulation, where one oocyte completes meiosis I and II only after fertilization.
This is a powerpoint presentation that discusses about the topic or lesson: Thomson's Atomic Model. It also includes the history of Joseph John Thomson, characteristics and concepts of Thomson's Atomic Model.
Chemical bonding involves atoms forming stable electronic configurations through gaining, losing or sharing electrons. Ionic bonds form between metals and nonmetals when electrons are transferred, while covalent bonds involve sharing electron pairs between nonmetals to achieve stable octets. Different bond types including ionic, covalent and metallic bonding can be identified based on the participating elements and electron configurations involved.
Rutherford performed an experiment in 1911 where he bombarded a thin gold foil with alpha particles. He observed that:
1) Most alpha particles passed through the foil without deflection.
2) A few particles were deflected by small angles.
3) Very few were deflected back at 180 degrees.
From these observations, Rutherford concluded that:
1) Atoms are mostly empty space.
2) A small, dense nucleus explains the few particles being deflected.
3) The nucleus is much smaller than the atom.
This module will help you gain knowledge about cell: the basic unit of all living matter. It is the unit of structure and function of which all plants and animals are composed. The cell is the smallest unit in the living organism that is capable of integrating the essential life processes. The cell is the key to biology because it is at this level that life truly springs. As you read this, you will learn more about the activities of the cell, the structures and the material of life that fills them. Later on, you will discover what a living matter is made of.
J.J. Thomson discovered electrons in 1897 using a cathode ray tube, which showed that cathode rays were streams of electrons. He proposed the plum pudding model of the atom, which depicted the atom as a ball of positive charge with negative electrons embedded inside. This contradicted Dalton's model of individual solid spheres, leading Thomson to disprove Dalton's model of atomic structure.
This document summarizes several genetic disorders caused by abnormalities in human chromosomes, including trisomies where there is an extra chromosome (such as Trisomy 13, 18, and 21), Turner Syndrome where there is missing X chromosome, and some of the common symptoms and facial features of each condition. It also discusses that genetic disorders affect almost 6% of births worldwide annually and that while many have no known cause, some may result from nondisjunction during meiosis where chromosomes do not separate properly.
There are two main types of cells - prokaryotic and eukaryotic cells. Prokaryotic cells were the earliest form of life and lack a nucleus and organelles. Eukaryotic cells are larger and more complex, with a nucleus that contains DNA organized into chromosomes and membrane-bound organelles. The key differences are that prokaryotes lack a nucleus and organelles while eukaryotes have these structures.
Convection currents are circular movements within liquids and gases caused by differences in density between hotter and cooler parts. Hot liquids are less dense than cold liquids, so hotter material rises while cooler, denser material sinks, creating a continuous cycle of circulation. This convection within Earth's mantle drives plate tectonics, as the rising and sinking of hot and cold mantle material carries lithospheric plates along with it.
Determining Geologic Time Scale using Absolute and Relative Dating Earth Scie...AshKyle2
The document discusses methods for determining the geologic time scale and dating geological features. It describes the four eons the geologic time scale is divided into and explains both relative and absolute dating techniques. Relative dating looks at relationships between geological features, while absolute dating uses measurements of radioactive isotopes in rocks and minerals to calculate their precise ages. Examples provided include William Smith's work identifying distinctive fossil sequences to correlate rock layers and the potassium-argon dating method.
The document summarizes the structure and function of eukaryotic cells and their organelles. It discusses that cells have three main jobs: 1) make energy through cellular respiration and photosynthesis using mitochondria and chloroplasts, 2) make proteins using instructions from DNA and structures like the nucleus, ribosomes, ER and Golgi apparatus, and 3) make more cells through DNA replication and cell division aided by the nucleus and centrioles. The organelles each have specialized structures and functions that allow the cell to carry out these essential life processes.
The document discusses comparative primate anatomy between humans and other primates like chimpanzees. Some key differences noted are:
- Humans have a larger brain size that allows for advanced language and tool-making abilities. In contrast, chimpanzee brains are smaller and lack specialized language areas.
- Human skulls have a higher forehead, smaller teeth, and less protruding jaws compared to chimpanzees.
- Features like opposable thumbs and straight fingers allow humans to develop precision grips for finer tool use than other primates.
- Bipedalism is unique to humans and freed the hands for carrying and making tools.
1. Meiosis is a cell division process that produces gametes, or sex cells, with half the number of chromosomes as the original cell.
2. During meiosis, homologous chromosome pairs separate into different daughter cells through two cell divisions, reducing the chromosome number.
3. The end result of meiosis is four haploid cells each with a single set of chromosomes, whereas mitosis produces two diploid cells with a full set of chromosomes.
Meiosis is a two-step process that results in four haploid cells each containing half the number of chromosomes of the original diploid cell. In the first phase, meiosis I, homologous chromosome pairs separate into two daughter cells. In meiosis II, the daughter cells undergo division again without DNA replication, resulting in four haploid cells each with one set of chromosomes. Meiosis reduces the chromosome number in a cell to produce gametes involved in sexual reproduction, while mitosis replicates chromosomes to produce body cells.
Meiosis is a type of cell division that produces gametes, such as sperm or egg cells, with half the normal number of chromosomes. It involves two rounds of cell division, meiosis I and meiosis II, which result in four haploid daughter cells each containing a single set of chromosomes. During meiosis I, homologous chromosomes pair and separate, reducing the chromosome number by half. Meiosis II then separates the sister chromatids, resulting in four haploid cells that can fuse during fertilization. Meiosis ensures genetic variation between offspring by independent assortment and crossing over of homologous chromosomes.
Meiosis is the process by which germ cells are produced with half the normal number of chromosomes. It involves two rounds of cell division, Meiosis I and Meiosis II. In Meiosis I, homologous chromosomes pair up and crossover occurs, followed by the separation of homologous chromosomes into daughter cells. Meiosis II then separates the sister chromatids, resulting in four haploid cells each with one chromosome from each homologous pair. This ensures genetic variation between offspring. Male meiosis occurs over 64 days in the testes and results in four haploid spermatids from one primary spermatocyte. Female meiosis begins in the fetus but pauses at prophase I until ovulation in adulthood.
Mitosis and meiosis are two types of cell division. Mitosis produces two identical daughter cells through prophase, metaphase, anaphase and telophase. Meiosis produces four haploid cells through two divisions, meiosis I and meiosis II. Meiosis I separates homologous chromosomes and results in two haploid cells. Meiosis II separates sister chromatids to form a total of four haploid cells with only one chromosome from each pair. The key difference is that mitosis replicates somatic cells while meiosis forms gametes needed for sexual reproduction.
The human life cycle involves both mitosis and meiosis. Mitosis occurs during development and tissue repair, producing genetically identical cells. Meiosis occurs during sexual reproduction and reduces the chromosome number from diploid to haploid, generating genetically diverse gametes through independent assortment and crossing over. Fertilization of an egg and sperm fuses their haploid cells to form a diploid zygote, continuing the life cycle.
Meiosis is a two-stage cell division process that produces four haploid cells from one diploid cell. It begins with a single diploid cell containing two sets of duplicated chromosomes. The two stages are meiosis I and meiosis II. In meiosis I, homologous chromosome pairs align and separate, resulting in two haploid cells. Meiosis II then divides the contents of these two cells into four haploid cells, each containing one representative from each chromosome pair. This process ensures genetic diversity in offspring.
Meiosis is a type of cell division that produces gametes, such as eggs and sperm, which contain half the number of chromosomes found in regular body cells. It involves two rounds of cell division without an intervening DNA replication phase. In the first round, homologous chromosomes pair up and may exchange genetic material through crossing over. The homologous chromosomes then separate, reducing the chromosome number. The second round separates the sister chromatids, resulting in four haploid daughter cells. This process ensures genetic variation in offspring through independent assortment and crossing over during meiosis I.
Activity 3-4 March ( Professional Studies)3AKarabo Dichaba
This document describes the process of meiosis. It begins by explaining that human somatic cells are diploid, containing 23 pairs of homologous chromosomes, with one chromosome from each parent. Meiosis is then defined as the process that converts diploid cells to haploid cells. The summary proceeds to outline the key stages of meiosis I and meiosis II, including prophase I where homologous chromosomes pair up, metaphase and anaphase where the chromosomes separate, and telophase where the cell divides. The result of meiosis is four haploid cells, with half the number of chromosomes as the original cell.
Each body cell contains two sets of chromosomes from each parent, making them diploid. During meiosis, germ cells undergo two cell divisions to become haploid, with one set of chromosomes. Meiosis occurs through prophase I, metaphase I, anaphase I and telophase I, followed by Meiosis II which separates sister chromatids. In males, spermatogenesis takes 64 days from spermatogonia to spermatozoa through meiosis and spermiogenesis. In females, oogenesis begins in the fetus but pauses at prophase I until ovulation, where one oocyte completes meiosis I and II only after fertilization.
Meiosis produces gametes with half the number of chromosomes as the original parent cell to allow for fertilization and the combination of genetic material from two parents. It involves two cell divisions: Meiosis I separates homologous chromosome pairs, and Meiosis II separates sister chromatids. This process, along with independent assortment and crossing over of chromosomes, introduces genetic variation among gametes to promote evolution of populations. Errors in meiosis can result in gametes with extra or missing chromosomes and cause conditions like Down syndrome if fertilization occurs.
Meiosis is a type of cell division that produces gametes, such as sperm and egg cells, with half the number of chromosomes as regular body cells. This allows offspring to have a full set of chromosomes from each parent. Meiosis involves two cell divisions after one round of DNA replication, resulting in four haploid cells from one original diploid cell. Genetic variation arises in meiosis through independent assortment of chromosomes and recombination during crossover. Nondisjunction is when chromosomes fail to separate properly, resulting in gametes with extra or missing chromosomes and genetic disorders like Down syndrome.
This document summarizes the process of meiosis. It begins by explaining that meiosis produces haploid gametes from diploid body cells to allow for sexual reproduction. It then describes the key phases and events of meiosis I and meiosis II, including homologous chromosome pairing, crossing over, and independent assortment. This genetic recombination during meiosis provides variation in offspring. The document concludes by discussing how nondisjunction can occasionally occur, resulting in gametes with an extra or missing chromosome and leading to conditions like Down syndrome.
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11.16 (dr. sadaf) meiosis + comparison with mitosisFati Naqvi
Meiosis and mitosis are compared. Meiosis involves two cell divisions that result in four haploid cells with half the number of chromosomes, while mitosis results in two diploid daughter cells with the same number of chromosomes as the parent cell. Meiosis allows for genetic diversity and chromosomal assortment during gamete formation, and has steps of prophase I, metaphase I, anaphase I, telophase I, prophase II, etc. leading to four haploid cells. Mitosis is for growth and tissue repair resulting in two identical diploid cells through the steps of interphase, prophase, metaphase, anaphase and telophase.
Top 7 Meiosis And Mitosis Differences.pdfChloe Cheney
Learn about the seven most common meiosis and mitosis differences with our complete guide to differences and similarities between mitosis and meiosis and more
The document provides an overview of meiosis cell division. It defines meiosis as a type of cell division that produces gametes with half the normal number of chromosomes. Meiosis occurs in two stages, Meiosis I and Meiosis II, and has four phases - prophase, metaphase, anaphase and telophase. In meiosis I, homologous chromosomes pair and may exchange genetic material through crossing over, resulting in genetic variation. This reduces the chromosome number from diploid to haploid. Meiosis II then divides the haploid cells into four haploid daughter cells.
Meiosis reduces the number of chromosomes in cells from diploid to haploid. It has two divisions. In meiosis I, homologous chromosome pairs separate into individual chromosomes. In meiosis II, sister chromatids separate, resulting in four haploid cells. Meiosis increases genetic diversity through independent assortment and crossing over during prophase I. This ensures offspring receive a unique set of genes from each parent.
Meiosis is a cell division process that produces haploid gametes from diploid germ cells. It involves two rounds of nuclear division and cell division. The first division, Meiosis I, separates the homologous chromosomes. The second division, Meiosis II, separates sister chromatids. This results in four haploid daughter cells each with half the number of chromosomes as the original parent cell. Meiosis ensures genetic variation between offspring and allows for sexual reproduction through the fusion of male and female gametes during fertilization.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
2. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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
segregation and independent assortment,
as Mendel had described?
4. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
6. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
These 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.
7. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
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.
8. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.”
The gametes of sexually reproducing organisms are haploid.
For fruit fly gametes, the haploid number is 4, which can be written as
N = 4.
10. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Phases of Meiosis
What events occur during each phase of meiosis?
In prophase I of meiosis, each replicated chromosome pairs with its
corresponding homologous chromosome.
During metaphase I of meiosis, paired homologous chromosomes line up
across the center of the cell.
11. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Phases of Meiosis
What events occur during each phase of meiosis?
During anaphase I, spindle fibers pull each homologous chromosome pair
toward opposite ends of the cell.
In telophase I, a nuclear membrane forms around each cluster of
chromosomes. Cytokinesis follows telophase I, forming two new cells.
12. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Phases of Meiosis
What events occur during each phase of meiosis?
As the cells enter prophase II, their chromosomes—each consisting of two
chromatids—become visible.
The final four phases of meiosis II are similar to those in meiosis I.
However, the result is four haploid daughter cells.
13. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Phases of Meiosis
Meiosis 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.
Meiosis usually involves two distinct divisions, called meiosis I and meiosis
II.
By the end of meiosis II, the diploid cell becomes four haploid cells.
14. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Meiosis I
Just prior to meiosis I, the cell undergoes a round of chromosome
replication called interphase I.
Each replicated chromosome consists of two identical chromatids joined at
the center.
15. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Prophase I
The cells begin to divide, and the chromosomes pair up, forming a
structure called a tetrad, which contains four chromatids.
16. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
17. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
18. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Metaphase I and Anaphase 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.
19. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Metaphase I and 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.
20. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Telophase I and Cytokinesis
During telophase I, a nuclear membrane forms around each cluster of
chromosomes.
Cytokinesis follows telophase I, forming two new cells.
21. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Meiosis I
Meiosis I results in two cells, called
daughter cells, each of which has four
chromatids, as it would after mitosis.
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.
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.
22. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Meiosis 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.
23. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
26. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Telophase II, and Cytokinesis
In the example shown here, each of the four daughter cells produced in
meiosis II receives two chromatids.
28. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gametes to Zygotes
The haploid cells produced by meiosis II are gametes.
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.
29. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
31. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Comparing Meiosis 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.
32. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Comparing Meiosis 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.
33. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Comparing Meiosis 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.
34. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Comparing Meiosis 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.
35. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
36. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
37. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
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.
38. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Changes in Chromosome Number
Mitosis does not normally change the chromosome number of the original
cell.
Meiosis reduces the chromosome number by half.
39. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Changes in Chromosome Number
A diploid cell that enters mitosis with eight four chromosomes will
divide to produce two diploid daughter cells, each of which also has
eight four chromosomes.
40. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Changes in Chromosome Number
On the other hand, a diploid cell that enters meiosis with eight four
chromosomes will pass through two meiotic divisions to produce four
haploid gamete cells, each with only four two chromosomes.
41. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Number of Cell Divisions
Mitosis is a single cell division, resulting in the production of two
genetically identical diploid daughter cells.
42. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Number of Cell Divisions
Meiosis requires two rounds of cell division, and, in most organisms,
produces a total of four genetically different haploid daughter cells.
44. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Linkage and Gene Maps
How can two alleles from different genes be inherited together?
Alleles of different genes tend to be inherited together from one generation
to the next when those genes are located on the same chromosome.
45. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Linkage
Thomas Hunt Morgan’s research on fruit flies led him to the principle of
gene linkage.
After identifying more than 50 Drosophila (fruit fly) genes, Morgan
discovered that many of them appeared to be “linked” together in ways that
seemed to violate the principle of independent assortment.
46. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Linkage
For example, Morgan used a fly with reddish-orange eyes and miniature
wings in a series of test crosses.
His results showed that the genes for those two traits were almost always
inherited together.
Only rarely did the genes separate from each other.
47. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Linkage
Morgan and his associates observed so many genes that were inherited
together that, before long, they could group all of the fly’s genes into four
linkage groups.
The linkage groups assorted independently, but all of the genes in one
group were inherited together.
As it turns out, Drosophila has four linkage groups and four pairs of
chromosomes.
48. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Linkage
Morgan’s findings led to two remarkable conclusions:
First, each chromosome is actually a group of linked genes.
Second, it is the chromosomes that assort independently, not individual
genes.
Alleles of different genes tend to be inherited together when those genes
are located on the same chromosome.
49. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Mapping
In 1911, Columbia University student Alfred Sturtevant wondered if the
frequency of crossing-over between genes during meiosis might be a
clue to the genes’ locations.
Sturtevant reasoned that the farther apart two genes were on a
chromosome, the more likely it would be that a crossover event would
occur between them.
If two genes are close together, then crossovers between them should
be rare. If two genes are far apart, then crossovers between them
should be more common.
50. LLeessssoonn OOvveerrvviieeww MMeeiioossiiss
Gene Mapping
By this reasoning, he could use the frequency
of crossing-over between genes to determine
their distances from each other.
Sturtevant gathered lab data and presented a
gene map showing the relative locations of
each known gene on one of the Drosophila
chromosomes.
Sturtevant’s method has been used to
construct gene maps ever since this discovery.