University of Santo Tomas Grade 8 Science PDF

Summary

This presentation introduces topics on reproduction, including asexual and sexual reproduction. It covers types of asexual reproduction, such as budding, spore formation, binary fission, and fragmentation, and natural and artificial vegetative propagation, and also covers the human reproductive system. It includes diagrams and examples to explain each concept.

Full Transcript

ENGAGE Introduction to Sexual and Asexual Reproduction Why is reproduction important for the survival of species? GRADE 8 SCIENCE TOPIC 2.5 TYPES OF REPRODUCTION MR. MARK CHRISTIAN AQUINO LEARNING OBJECTIVE/S At the end of th...

ENGAGE Introduction to Sexual and Asexual Reproduction Why is reproduction important for the survival of species? GRADE 8 SCIENCE TOPIC 2.5 TYPES OF REPRODUCTION MR. MARK CHRISTIAN AQUINO LEARNING OBJECTIVE/S At the end of the session, you are expected to: 1. compare and contrast asexual and sexual reproduction; 2. describe the advantages and disadvantages of each type of reproduction; and 3. classify organisms if it undergoes sexual or asexual reproduction. IEXPLORE REPRODUCTION Reproduce means “to make new life”. It is the process by which organisms produce offspring. It enables and ensures the continuity of species, generation after generation TWO TYPES OF REPRODUCTION Sexual Reproduction Asexual Reproduction TWO TYPES OF REPRODUCTION Asexual Reproduction It refers to the formation of new individuals without involving sex cells or gametes. The offspring contain genetic information from only one parent. Aside from mutations that occur during replication, all offspring are identical to the parent and to one another. It is performed by many lower forms of organisms. EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters Example: REPCUDORTION NROEIPTROCDU REPRODUCTION EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 1. GBDUDIN BUDGIND BUDDING TYPES OF ASEXUAL REPRODUCTION BUDDING A parent organism produces offspring by growing a tiny replica of itself, in a form of an outgrowth called a bud, on some parts of the body. After the bud has grown enough, it falls off and becomes an independent and exact copy of the parent. Hydra Yeast EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 2. PSORE ESROP SPORE MATINOFRO ROFAMTION FORMATION TYPES OF ASEXUAL REPRODUCTION SPORE FORMATION These spores are dispersed into the air, where they germinate and create a new individual under favorable conditions. Ferns Bread molds EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 3. YBNAIR BIANRY BINARY SIFSION SSFIOI FISSION TYPES OF ASEXUAL REPRODUCTION BINARY FISSION An organism divides into two, after which each half grows into a new organism. Euglena Paramecium EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 4. FRAGATNEMNTIO NEMFRAGNIOTTA FRAGMENTATION TYPES OF ASEXUAL REPRODUCTION FRAGMENTATION In this asexual type of reproduction, the parent body, breaks up into several pieces. The pieces of fragments develop into new organisms. Sponges Flatworms Sea star EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 5. LARTANU NAUTRAL NATURAL TEGEVEVITA VEGATETIVE VEGETATIVE PNROOIPTAAG PRGAPAOTION PROPAGATION TYPES OF ASEXUAL REPRODUCTION NATURAL VEGETATIVE PROPAGATION It is the type of reproduction from the plant’s vegetative parts or specialized reproductive structures. In this process, new plants are produced from the eyes (nodes). Tuber Runner Corm Rhizome Bulb New shoots arise New plants arise at the New plants arise from very New plants arise at the New bulbs arise from an from an auxiliary nodes of a horizontal short thick underground nodes of a horizontal auxiliary bud on very short bud. stem above the stems with thin scaly robot-like underground stems with thick fleshy ground. leaves. stem. leaves. EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 6. LAARITCIIF ARCIFITIAL ARTIFICIAL TEGEVEVITA VEGATETIVE VEGETATIVE PNROOIPTAAG PRGAPAOTION PROPAGATION TYPES OF ASEXUAL REPRODUCTION ARTIFICIAL VEGETATIVE PROPAGATION It is often faster than growing plants from seeds. Farmers propagate plants by using a piece of plant material. Cutting Budding and Grafting Tissue Culture Leave, stems or roots are Small stems from one plant attached Pieces of tissues from one plant are cut from one plant, planted to larger stems or roots of another placed on a sterile medium and used in soil, and used to grow plant. to grow new plants. new individuals. ADVANTAGES AND DISADVANTAGES OF ASEXUAL REPRODUCTION Advantages quick reproduction does not need a partner offspring are identical all offspring are able to produce more offspring; can produce many offspring at one time Disadvantages cannot adapt to a changing environment no genetic variation (unless mutation occurs) TWO TYPES OF REPRODUCTION Sexual Reproduction It involves the union of gametes; the sperm (or male gamete) fuses with egg (or female gamete) to form a fertilized egg or zygote. Sexual reproduction happens in the sexual organs of flowering plants, which are contained in the flower. EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 7. NPNOOLLTINA POLLTIONAI POLLINATION STAGES OF SEXUAL REPRODUCTION IN PLANTS POLLINATION It refers to the transfer of pollen grains from the anther to the stigma. Pollen grains produced by the anther of one plant land on and stick to the stigma of the flower of another plant. Self pollination Cross pollination EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 8. REONFILZIATRT FREZATILITION FERTILIZATION STAGES OF SEXUAL REPRODUCTION IN PLANTS FERTILIZATION Once the pollen lands on the sticky, sugary substance that covers the stigma, a tube-like structure grows from the stigma and elongates to form the pollen tube. The ovary swells and ripens to form a fruit, which may contain one or many seeds. Inside the seed, a plant embryo awaits growth EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 9. DEES SEDE LASREPSID DISSREPAL SEED DISPERSAL STAGES OF SEXUAL REPRODUCTION IN PLANTS SEED DISPERSAL Plants have several methods of dispersing seeds: by wind, water, animal, or explosion. AGENTS OF SEED DISPERSAL EXPLORE/ EXPLAIN Guess the terms related to Asexual Reproduction using the jumbled letters 10. NGOEIRTMANI GENARMITION GERMINATION STAGES OF SEXUAL REPRODUCTION IN PLANTS GERMINATION When the seed, sometimes with its fruit, lands on the ground, it breaks through the seed coat and grows to form a new plant. Once the plant is above the ground, the plant begins to grow leaves and produce food by photosynthesis. SEXUAL REPRODUCTION IN ANIMALS FERTILIZATION It refers to the union of sperm and egg cell of the male and female respectively to produce an offspring. TYPES OF FERTILIZATION External Fertilization Internal Fertilization occurs outside of the body occurs inside of the body ADVANTAGES AND DISADVANTAGES OF SEXUAL REPRODUCTION Advantages increases genetic variation offspring is not identical to parent increases chance of survival in changing environments requires complex structures Disadvantages does require another organism to mate slow reproduction COMPARING TWO TYPES OF REPRODUCTION Asexual Reproduction Sexual Reproduction It involves single organism. It involves one or two organisms. There is no production of gametes. Male and female gametes are produced. There is no fusion of gametes. It involves fusion of gametes. It produces offspring that are identical Offspring will have some characters from to the parent. male and others from female. There is no genetic variation. There are more chance of genetic variation. Dive into Blood Circulation with Simulation! EXTEND LET’S CLASSIFY ORGANISMS! GRADE 8 SCIENCE TOPIC 2.6 (Part 1) HUMAN REPRODUCTIVE SYSTEM MR. MARK CHRISTIAN AQUINO LEARNING OBJECTIVE/S At the end of the session, you are expected to: 1. identify the parts and functions of male and female reproductive systems; 2. discuss the role of hormones involved in the male and female reproductive system; and 3. explain the effect of hormone secretion in the development of an organisms. ENGAGE/ EXPLORE Introduction to Male Reproductive System Label the parts of male reproductive system, write your answer in your notebook. ENGAGE/ EXPLORE Introduction to Male Reproductive System REPRODUCTIVE SYSTEM WHAT ARE THE FUNCTIONS OF REPRODUCTIVE SYSTEM? 1 c Produce offspring 2 c Pass on traits 3 c Perpetuate the species MALE REPRODUCTIVE SYSTEM FUNCTIONS OF MALE REPRODUCTIVE SYSTEM Produce sperm Secrete male sex hormone Deliver sperm in site of fertilization SPERM CELL male gametes or spermatozoa produced in testes MAIN PARTS OF A SPERM MAIN PARTS OF A SPERM HEAD o nucleus – houses male chromosome o acrosome – protective cap MIDPIECE o mitochondria – supply energy TAIL o whiplike structure that propels SPERMATOGENESIS Link to the video: https://youtu.be/muC0FpM6_R8 MALE REPRODUCTIVE ANATOMY o Testes o Ducts Epididymis Vas deferens Urethra o Accessory glands Seminal vesicles Prostate gland Bulbourethral glands o Supporting structures Scrotum and penis ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! TESTES MALE REPRODUCTIVE ANATOMY TESTES o two reproductive glands located in scrotum o responsible for the production of sperm MALE REPRODUCTIVE ANATOMY TESTES SEMINIFEROUS TUBULE o highly coiled tubes o produce the sperm o sperm factories ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! SCROTUM MALE REPRODUCTIVE ANATOMY SUPPORTING STRUCTURES SCROTUM sac containing testes MALE REPRODUCTIVE ANATOMY SUPPORTING STRUCTURES SCROTUM Dartos muscle o smooth muscle that wrinkles scrotal skin Cremaster o bands of skeletal muscle that elevate the testes ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! PENIS MALE REPRODUCTIVE ANATOMY SUPPORTING STRUCTURES PENIS o copulatory organ designed to deliver sperm into the female reproductive tract MALE REPRODUCTIVE ANATOMY Reproductive ducts push sperm and semen through the internal genitalia. EPIDIDYMIS VAS DEFERENS EJACULATORY DUCTS URETHRA ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! EPIDIDYMIS MALE REPRODUCTIVE ANATOMY DUCTS EPIDIDYMIS o a coiled tube system located on the testes o where sperm cells are temporary stored and matured ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! VAS DEFERENS MALE REPRODUCTIVE ANATOMY DUCTS VAS DEFERENS o propels sperm from the epididymis to the urethra MALE REPRODUCTIVE ANATOMY DUCTS EJACULATORY DUCTS o blocks the passageway from the bladder to prevent urine from mixing with the sperm ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! URETHRA MALE REPRODUCTIVE ANATOMY DUCTS URETHRA o the outlet tube for both the excretory system and reproductive system MALE REPRODUCTIVE ANATOMY Accessory reproductive glands add seminal fluid to semen SEMINAL VESICLE PROSTATE GLAND BULBOURETHRAL GLAND ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! SEMINAL VESICLE MALE REPRODUCTIVE ANATOMY ACCESSORY GLANDS SEMINAL VESICLE o contributes to about 60% of the total volume of the semen o contains a fructose-rich fluid that nourishes the sperm ENGAGE/ EXPLORE Introduction to Male Reproductive System Identify this part! PROSTATE GLAND MALE REPRODUCTIVE ANATOMY ACCESSORY GLANDS PROSTATE GLAND o located below the bladder o secretes an alkaline that neutralizes acids present in the female reproductive organ MALE REPRODUCTIVE ANATOMY ACCESSORY GLANDS BULBOURETHRAL GLAND o secretes an alkaline fluid that neutralizes acid present in the urethra HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM Hypothalamus Gonadotropin-releasing hormone Anterior pituitary Follicle – stimulating Luteinizing hormone hormone Sertoli Cells Leydig Cells Inhibin Testosterone SPERMATOGENESIS HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM FOLLICLE – STIMULATING HORMONE o stimulates Sertoli cells to nourish developing sperm HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM FOLLICLE – STIMULATING HORMONE SERTOLI CELLS INHIBIN o acts on the anterior pituitary gland to reduce FSH secretion HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM LUTEINIZING HORMONE o causes Leydig cells to produce testosterone and other androgens HORMONES INVOLVED IN MALE REPRODUCTIVE SYSTEM LUTEINIZING HORMONE LEYDIG CELLS TESTOSTERONE o promotes spermatogenesis o regulates blood level of GnRH, FSH, and LH through inhibitory effects on the hypothalamus and anterior pituitary Dive into Blood Circulation with Simulation! EXTEND LESSON SYNTHESIS Today, you learned that… 1. Sperm travel through the epididymis, ductus deferentia, and ejaculatory duct, and they exit the body with semen through the urethra. Gonadotropin-releasing hormone from the hypothalamus stimulates the anterior pituitary gland to release FSH and LH. In males, these hormones affect the testes, triggering the release of testosterone necessary for sperm production. REFERENCE o Hoefnagels, Marielle (2019). Second Edition: General Biology (Books I and II). McGrawHill Education pages 599 – 609

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