...WHAT IS CELL REPRODUCTION AND WHY IT HAPPENS According to our text book, Essentials of Biology, we begin life as a single cell but over the period of several months, we become a collection of trillions of cells. This process continues as we grow up and as we reach a fully mature adult age, old cells are replaced with new ones. Many cells divide at least once during their short life span and some divide many times before they die. This is known as cell division (parent cells and daughter cells) which are given the names of binary fission, meiosis and mitosis. New red blood cells, skin cells and digestive track cells are also generated. Reproduction is also how organisms are able to reproduce through meiosis which involves the replication of DNA and the splitting of molecules. Mitosis involves the cell division which produces two of the same identical cells from one single cell and happens as a result of a process that cells go through to form to nuclei with each of the nuclei containing the same number of chromosomes. Many eukaryotic organisms use this process for reproduction. Cells go though many cycles but all of the cycles happen in a specific event, some of which I partially mentioned above. The first in the Interphase cycle which is time it takes for a cell to perform its normal functions, depending on where it is in the human body. The next stage is the M state which includes both the division of the nucleus and the division of the cytoplasm—this is where...
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...Cell Reproduction Introduction Cellular reproduction is the process by which cells duplicate their contents and then divide to yield two cells with similar, if not duplicate contents. Life as we know it depends on the ability of cells to store, retrieve and translate the genetic instructions required to make and maintain a living organism. In this assignment, I will discuss two different types of cell reproduction, mitosis and meiosis and, include the different stages required in order for the reproduction to take place. Mitosis Mitosis is a process by which a cell divides to form two daughter cells and produces an almost carbon copy of the parent cell. The daughter cells will consist of the same number and type of chromosomes as the parent cell and will be identical to each other. Although cell division is the defining characteristic of mitosis, a number of events must take place during mitosis prior to the splitting of the cell. There are four phases that constitute the period in which cells make preparation for cell division. The four phases are prophase, metaphase, anaphase and telophase. Prophase, the first stage of mitosis during which the chromosomes become shorter, thicker and consist of two chromatids. At this time, the chromosomes are still enclosed in the cell nucleus within the nuclear envelope. The chromosomes also contain a centromere, which is necessary in later phases for attachment to microtubules for migration. Late in prophase, kinetochores...
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...BSC 1020- Reflection Unit E Making Babies and Splitting Up Chapter 8 focuses on cellular reproduction. Cellular reproduction is the process of producing cells into new ones. In cell division chromosomes are duplicated, new cells grow, and this allows for reproduction. There are two types of reproduction which are sexual and asexual. Asexual does not require the fertilization of an egg by a sperm and uses meiosis for reproduction. In asexual reproduction there is one parent and the offspring have identical genes from the single donor. Sexual reproduction uses both meiosis and mitosis because it requires the fertilization of eggs by the sperm. In sexual reproduction the genetic material of the offspring is varied because the two donors...
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...1 ANIMAL DEVELOPMENT BEGINS WITH REPRODUCTION Reproduction, growth, and development are shared features of ALL multicellular life. A. REPRODUCTION IS ASEXUL OR SEXUAL ASEXUAL REPRODUCTION – offspring contain genetic info from only one parent and are identical to the parent and each other. Advantageous in environments that don’t change much over time. EX. Include aphids, some types of lizards SEXUAL REPRODUCTION – requires genetic info from two parents. Advantageous in changing environments. GAMETES – products of meiosis, haploid sex cells that carry genetic info from each parent (sperm/eggs) ZYGOTE – diploid product of fertilization, new offspring. EXTERNAL FERTILIZATION – males and females release gametes into the same environment and fertilization occurs outside the body. Especially common in aquatic animals. Unique “recognition” proteins on the surface of gametes keep sperm cells from fertilizing eggs of the wrong species. EX. Salmon, sponges, corals, sea urchins, some amphibians INTERNAL FERTILIZATION – a male deposits sperm inside a female’s body, where fertilization occurs. After copulation, animals may lay hard-shelled eggs or bear live young. B. DEVELOPMENT IS INDIRECT OR DIRECT DEVELOPMENTAL BIOLOGISTS – study the stages of an animal’s growth as cells specialize and interact to form tissues, organs, and organ systems. Differentiation and pattern formation involve complex interactions between the DNA inside cells and external signals such as hormones...
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...human beings, plants, insects, animals among others. A living thing is defined as using all of these qualities: movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition. Only living things, and all living things, have these functions. A living thing is any organism that displays all the characteristics of life. These include being able to grow and use energy. They must also consist of at least one cell. You can find more information here: Theme #1 - Cells All living things are composed of one or more cells. Different types of cells have different "jobs" within the organism. Each life form begins from one cell, which then will split. These cells split, and so on. After this has happened several times, differentiation is undergone, when the cells change so that they are not the same thing anymore. Then they are used to begin to put together the final organism, some cells, for example, as the eyes, some as the heart, etc. The only arguable exception to this is viruses. They are not composed of cells, but are said to be "living." Theme#2 - Organization Complex organization patterns are found in all living organisms. They arrange themselves on very small levels, grouping like things together. On larger levels, they become visible. This also has to do with differentiation, as the cells are organized in a manner that makes sense for the organism after they change to what they'll be in the final organism. Theme#3 - Energy Use All organisms use...
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...BIOL/ BMSC 114: Asexual vs. sexual reproduction Asexual and sexual reproduction • Two modes of animal reproduction: asexual and sexual reproduction. – In most cases asexual reproduction relies on mitotic cell division. – Sexual reproduction is the creation of offspring by fusion of haploid gametes to form a zygote. • Gametes are formed by meiosis. • Sexual reproduction directly reduces your contribution to the next generation! Phil Lester, KK413 3 Asexual reproduction • Asexual reproduction has many advantages: – All your wonderful genes are contributed to the next generation (no dilution!). – It enables animals living in isolation to reproduce. – It can create numerous offspring in a short amount of time. • Theoretically it is most advantageous in stable, favourable environments because it perpetuates successful genotypes precisely. Types of asexual reproduction: Fission. • Many invertebrates reproduce asexually by fission. – The separation of a parent into two or more individuals of roughly equal size. Phylum Cnidaria– sacs with central digestive system. 4 5 Types of asexual reproduction: Budding. • A new individual splitting off from an existing one. – For example certain species in the Phylum Cnidaria: new individuals grow out from the body of a parent. – May detach or remain joined to the parent. Phylum Cnidaria– hydras can reproduce sexually when conditions are unfavourable. 6 Types of asexual reproduction: Fragmentation. • The breaking of the...
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...AC 1.1 By Life Processes common to living organisms Laura Judges TABLE OF CONTENTS Chapter 1 page Introduction to life processes 2 Chapter 2 page Movement 2-3 Chapter 3 page Repoduction 3 Chapter 4 page Sensitivity 3-4 Chapter 5 page Growth 4 Chapter 6 page Respiration 5 Chapter 7 page Excretion 5-6 Chapter 8 page Nutrition 6-7 Chapter 9 page Conclusion 7-8 Chapter 10 page Bibilography 9 Introduction to life processes The most basic of living things consist of just one single cell for example bacteria, while more complex organisms such as humans are multi-cellular. An organism is defined as an individual animal, plant or single-celled life form. Therefore the cell is considered the smallest unit of life competent of a self-sufficient existence. There are seven things that all living organisms from bacteria to plants to animals all have in common and whether something is living or not is usually compared to the seven life processes. These processes are movement, reproduction, sensitivity, growth, respiration, excretion and nutrition. The acronym ‘MRS GREN’ will be used when discussing the processes of life movement All living things move to some kind of degree and this is the most apparent within the animal kingdom. Animals are able to physically move themselves from one place to another; humans will usually use their muscles in order to be able to move where as other animals may have to hop, crawl, swim or fly. Movement is very important for gathering sustenance...
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...Reproductive System Reproduction- Is the process by which new living organisms are produced from existing living organisms. The Male Reproductive System The Parts of the male reproductive system are: 1.Testes/Testicles-produces the male sex cells. (sperm cells) 2.Epididymis-stores the sperms produced by the testes. 3.Scrotum/Scrotal Sac-is the skin that protects the testes. -it holds the testicles. 4.Penis-is the part of the organ that hangs in front of the scrotum. -it deposits the sperm cells into the vagina. 5.Urethra-is a tube where the sperm and the urine pass through. 6.Vas Deferens-where the sperms travel. 7.Prostate Gland-The prostate is a walnut-sized gland located between the bladder and the penis. Female Reproductive System 1.Fallopian Tube-It is where the egg cell travels from the ovary and where fertilization takes place. 2.Ovaries-produces thousand of eggs. 3.Uterus-It is where the fetus develops into a baby. 4.Fimbriae-fringe of tissue around the Fallopian tube in the direction of the ovary. 5.Cervix-It stretches open wide enough for the baby to pass through during delivery. 6.Vagina-It is an elastic vascular muscle of female reproductive Organ that expands during giving birth. *The Male Hormones(Testosterone) *The Female Hormones(Estrogen and Progesterone) *The Male Reproductive System is designed for the reproduction and transportation of sperm cells which are needed for fertilization. *The Female Reproductive...
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...Week 1 Assignment: The Sperm and the Egg Nathaniel Morris PSY/265 3/18/2012 Nicole Pansey Week 1 Assignment: The Sperm and the Egg Many of us have heard about the birds and the bees. Most parents find this story to better illustrate how conception happens. When a young child asks their parent “Where do babies come from”, a parent may find it hard to look in their young child’s eyes, and describe exactly what happens. The actual scientific process may be harder to explain, but will be more useful for the child when they get older. It would probably be more effective with a variety of visual aids, and preparation in order to present this to an adolescent. Deciding at what age to tell your child the scientific version should depend on the parent. The “birds and bees story” may be more appropriate for a younger child, and the scientific version can be more explained when they are a little more mature. A girl should know about the sexual reproductive system when she starts menstruating. If she is not taught properly, she may not understand what is going on with her body, and may wind up pregnant at an early age. In order to explain the scientific version, first, you would have to start out by explaining the immediate male and female body parts that are involved; the penis and vagina. The inner part of the vagina consists of two ovaries, the cervix, and the uterus that are all connected to the uterus by the fallopian tubes. These are all structures that make up the...
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...1. Cellular Organization 2. Reproduction 3. Metabolism 4. Homeostasis 5. Heredity 6. Response to Stimuli 7. Growth and Development 8. Adaptation through Evolution 1. There are some certain points when discussing about living and non-living things. They are mostly specific on living things such as cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development and adaption through evolution. Things which have these characteristics are called as living things and things which haven’t are called as non-living things. On certain occasions we can identify living things that miss one or several characteristics from the list. For an example trees don’t show direct movements, just only the growth movements, neurons don’t reproduce, the animals that have non sexual reproductive system and the trees which are reproduced by propagation don’t show adaptations or evolutions. Importantly, some non-living things too show one or several characteristics that defines life. For an example if we think about computer it’s a logical machine, it consumes electricity. So it shows metabolism, it control its’ temperature. That’s homeostasis. It responses to stimuli. Every day its’ storage memory grows bigger. So it shows the growth. If we think about a vehicle it shows clear movements, it needs fuel to run. So that’s metabolism. While driving wheels turn where ever we turn the steering wheel. So that’s a response to stimuli...
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...Joyce Seo November 7, 2012 The Regeneration of Differently Cut Fragments of D. dorotocephala in a Solely Spring Water Medium Introduction: Planaria are free-living flatworms in the phylum Platyhelminthes that mainly live in fresh water, but can be found in the ocean as well as the soil. They all have a similar morphology that consists of a small, flat, bilateral body with a single orifice which functions as both the mouth and anus (Steinbach, 1962). They are usually hermaphroditic species that are able to reproduce both sexually and asexually. Sexual reproduction occurs by exchanging the gametes between two separate organisms. The planaria usually divides into half during asexual reproduction, and regenerates the missing body parts. This...
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...Sex chromosomes produce very unique patterns of inheritance in living organisms. In humans, there is an X chromosome and a Y chromosome that determines the sex of the offspring. A male has an X and Y chromosome, whereas a female has two X chromosomes. The sex of an offspring is determined by whether the sperm cell that fertilizes the egg is made up of an X or a Y chromosome; ultimately the male is the determining factor of the sex of the offspring. Even though the Y chromosome determines if the offspring will be male, the X chromosome has genes that control certain human characters; these genes are called sex-linked genes because they are linked to a certain sex. There are approximately 1,098 sex-linked genes that code unusual inheritance patterns other than the female sex trait. Some of these sex-linked genes carry unusual inheritance such as color blindness, Duchenne muscular dystrophy and hemophilia. (O’Neil, 2012). In the case of the recessive mutation that causes hemophilia, a female has to be the carrier of the mutated allele, since she has the X chromosomes only. If the female carrier of the disease mates with a male who has hemophilia (XhY), there would be a one-quarter chance that they would produce a female offspring that has hemophilia (XhXh). Males though are more susceptible to inheriting the hemophilia trait if the mother is a carrier, because the dominant gene (XH) will prevent the disease. (Simon, 2015). Since males can only have an X and a Y chromosome, there...
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... Sperm cell Sexual reproduction occurs when offspring result from the joining (fusion) of a male reproductive cell and a female reproductive cell. These special reproductive cells are called gametes and are made in the reproductive organs of organisms. In animals, male gametes are called sperm and female gametes are called ova (singular = ovum) or egg cells. Reproductive systems are designed to bring the male and female gametes together. The joining of sperm and egg cells is called fertilisation. This process mixes the genetic material from the nucleus of each parent together and results in the formation of a zygote. Human sperm cells surround an ovum. MEETING OUTSIDE … In some animals, especially those that live or breed in water such as fish and amphibians, fertilisation occurs outside the female's body. This is called external fertilisation. In this situation, the female releases her unfertilised eggs into the water to be fertilised by the male's sperm, which are also released into the water. MEETING INSIDE … In animals that live and breed on land, internal fertilisation occurs. This keeps the gametes inside the body so there is no chance of dehydration occurring. In this situation, sperm are introduced into the female by a process called copulation (or sexual intercourse). Some differences between internal and external fertilisation Sexual reproduction involves fusion of gametes. Page 184 Ova Like sperm, ova are produced by a special type of cell division...
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...* Hello my name Hayley Walker; I am a sophomore at Saint Joseph High school. This is my first time participating in PJAS; * I am currently in a science research class at St Josephs High School. My project involved the observation of planarian . My primary question concerned the impact that magnesium chloride played on the regrowth and/or reproduction process of planarian. * Before I began my research I was not very knowledgeable about the subject or these organisms. * From previous experiments too much chloride caused the cell to dry up. * My first reference was an abstract based on an experiment by Wolfgang Schurmann and Roland Peter. Their findings led me to believe that high levels of magnesium chloride are devastating to the regeneration of planarians. * When experimenting with planarian, the organism are dissected in order to observe their regrowth process, this cycle varies by area of dissection. This variable is caused by the amount of neoplast found in different regions of the, planarian, low levels of neoplast cause a slower regeneration while a more concentrated area of neoplast sped the regeneration process. Many of the sources and references varied, this led me to question the most effective area to dissect this organism and how to base my regeneration cycle on dissection area. The second part of the experiment consisted on how natural spring water, and water with levels of magnesium chloride influence the regeneration process. ...
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...biomes | Able to fly; covered with feathers | NutritionHow does the organism break down and absorb food? | Autotrophic | Heterotrophic: Earthworms eat their way through dirt, so they are detritivores. | Heterotrophic: Some are vegetarian, some are carnivorous, and some are decomposers. | Heterotrophic: These are usually vegetarian as tadpoles and carnivores as adults. | Heterotrophic | Circulatory System (Transport)How does the organism get what it needs to cells (open, closed, diffusion only)? | Diffusion only | Closed with 5 aortic arches (hearts) | Open circulatory system with a heart pumping hemolymph | Closed with 3-chambered heart | Closed with 4-chambered heart | Respiratory SystemHow does the organism get oxygen and release carbon dioxide? | Diffusion only | Diffusion through skin | Diffusion through tracheal tubes | Diffusion through gills as a tadpole and through lungs and skin (especially) as adults | Diffusion through the lungs | Reproductive SystemDoes the organism use asexual or sexual reproduction (eggs, seeds, spores, placenta, type of fertilization)? | Asexual | Hermaphrodites: One body has...
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