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Chapter 3: Reproduction 3A Methods of reproduction Learning intention Content descriptor Describe the form and function of I will be able to distinguish between sex...

Chapter 3: Reproduction 3A Methods of reproduction Learning intention Content descriptor Describe the form and function of I will be able to distinguish between sexual reproductive cells and organs in animals and asexual reproduction. and plants, and analyse how the processes of sexual and asexual reproduction enable survival of the species. Success measure Elaborations I can compare the process and outcomes of sexual explaining how the forms of male and and asexual reproduction. female gametes relate to their specific function exploring how sexual reproduction creates a greater rate of variation among offspring compared with asexual Connecting the dots Building on prior knowledge Year 9 Reproduction Year 8 Methods of Body systems reproduction depend Organs are on the different specialised structures within structures made an organism, of cells and and have different Year 10 Year 8 tissues that outcomes. Genetics Cells have specific Offspring Cells have functions within inherit a random specialised a system. combination of structures and parental traits functions. during sexual reproduction.  What do we know? Where do babies come from? James Steidl/Shutterstock.com METHODS OF REPRODUCTION Theory The purpose of reproduction Species on Earth continue to exist 1 KEY TERMS because of reproduction. reproduction biological Reproduction always produces offspring process that forms new (a.k.a. babies). individuals There are two ways to reproduce: offspring individual organisms formed 1. sexually through 2. asexually reproduction 2 genetic Each process passes genetic information instructions information onto the next generation, inherited from sustaining populations while also biological parents that allowing for adaptation and survival guide how an when organism grows, develops, and conditions change. functions Top to bottom: Andrey_Kuzmin and GreenThumbShots/Shutterstock.com METHODS OF REPRODUCTION Theory Sexual reproduction Sexual reproduction is commonly used by plants and animals. KEY TERMS This process produces offspring by combining genetic information from two parents. sexual reproduction This information is held in gametes, so the process involves bringing female and male combining genetic material from gametes together. two gametes to produce offspring Offspring produced through sexual reproduction have a random combination of traits parents organisms from both parents. This is why siblings are alike, but not identical. that provide a gamete gametes reproductive cells DID YOU KNOW? Having different combinations of traits in the species means there is a better chance that some of the population will survive if conditions change. Left to right: Jagodka, Toloubaev Stanislav, Eric Isselee, Csanad Kiss, and Nynke van METHODS OF REPRODUCTION Theory Gametes Gametes form in reproductive organs DID YOU KNOW? and contain half the information needed Gametes form to make an individual. through a process called meiosis. Combining gametes together forms a DON’T GET complete set of genetic information, so a TRICKED new organism can develop. Not all sperm have tails that can Male gametes (sperm) are usually small move them; Producing variation instead, some rely and streamlined, with a long flagellum Every gamete has a unique combination of on other processes information from the parent. So, every time to bring them to (tail) that helps them move through the an egg and sperm meet, a one-of-a-kind the egg. This female reproductive tract. organism can develop. is the case for some bees, Designua/Shutterstock.com Female gametes (eggs) are generally spiders, squid, and plants. much larger and immobile, providing protection, nutrients, and instructions for offspring growth. METHODS OF REPRODUCTION Theory Outcome of sexual reproduction Successful sexual reproduction always follows the same steps: KEY TERMS fertilisation fusing of male and Step 1: Two gametes (female and female gametes to form male) combine in a process called a zygote fertilisation. zygote first cell formed after fertilisation Step 2: This forms a single, WATCH ME Using variation to complete cell called a zygote. create Brussels sprouts Step 3: The zygote then divides DID YOU KNOW? and goes on to develop into a Zygotes divide through a process unique, independent organism. called mitosis, which doubles the amount of cells it has at each stage. METHODS OF REPRODUCTION Theory Asexual reproduction Asexual reproduction is commonly used KEY TERMS by bacteria, some fungi, and some plants. asexual It allows species to produce offspring reproduction using genetic faster than sexual reproduction as it: material from one parent to produce uses only one parent offspring does not usually involve gametes clones individuals with produces clones of the parent. the same genetic information as Sometimes, during asexual reproduction, the parent WANT MORE? small changes can happen within the Creating variety: genetic material. This can result in mutations offspring that are slightly different from Some common types of asexual reproduction the parent. This is how species that include: DID YOU KNOW? reproduce asexually can slowly change budding binary fission Commercial over time. fragmentation (shown in image) bananas, like the parthenogenesis. Cavendish, are clones, making them vulnerable to diseases and METHODS OF REPRODUCTION Theory Types of asexual reproduction Type Process Used by Binary fission one parent cell divides into two unique daughter single-celled prokaryotes, cells e.g. bacteria, blue-green algae some single-celled eukaryotes, e.g. amoeba, paramecium Amadeu Blasco/Shutterstock.com Fragmentation a piece of the parent body breaks off and both some eukaryotes, e.g. sea (a form of sections regrow stars, coral, sponge, binary Hydra fission) METHODS OF REPRODUCTION Theory Types of asexual reproduction Type Process Used by Budding an outgrowth on the parent body develops enough to some eukaryotes, e.g. survive on its own, then detaches yeast, Hydra, and some prokaryotes, e.g. bacteria. Parthenogenesis female parent produces offspring using only the only eukaryotes, e.g. female gamete whiptail lizards, bonnethead sharks METHODS OF REPRODUCTION Theory Video – Comparing reproduction methods Watch this clip for a comparison between sexual and asexual reproduction. https://www.youtube.com/watch?v=fcGDUcG jcyk Watch from 0:00 to 4:45 METHODS OF REPRODUCTION Theory Sum it up requires one requires two female: organism or gametes egg gamete male: sperm low rate of high rate of variation variation Reproductio asexual sexual n relatively quick relatively slow process involves process varies fertilisation METHODS OF REPRODUCTION Activity Skill Sharpener: Processing and analysing Representing methods of reproduction Follow the instructions to complete the activity 1. Create a diagram to summarise the process of sexual reproduction. Show how the offspring are different to the parents. 2. Create a diagram to summarise the process of one form of asexual reproduction. Show how the offspring are clones of the parent. 3. List two key differences between the two methods of reproduction. ACHIEVEMENT STANDARDS Year 8: Select and construct appropriate Year 9: Select and construct appropriate Year 10: Select and construct effective representations to organise and process representations to organise, process and representations to organise, process, and data and information. summarise data and information. summarise data and information. METHODS OF REPRODUCTION Activity Example answer Question 1 Question 3 Sexual reproduction Two differences: Sexual reproduction requires two different parents, asexual requires one parent. Sexual reproduction produces offspring that are different from Mironov Konstantin/Shutterstock.com the parents, while asexual Question 2 reproduction produces offspring Asexual reproduction (binary fission) that are clones of the parent. METHODS OF REPRODUCTION Check for understanding Question 1 Both sexual and asexual reproduction A have high rates of variation. B produce offspring. C require gametes. D form clones. METHODS OF REPRODUCTION Check for understanding Question 1 – answer Both sexual and asexual reproduction A have high rates of variation. B produce offspring. C require gametes. D form clones. All forms of reproduction produce new individuals to continue the species. METHODS OF REPRODUCTION Check for understanding Question 2 Egg cells are much larger than sperm cells because A sperm are stationary. B sperm provide extra nutrients. C eggs provide protection and nutrients. D eggs provide the majority of genetic information. SciePro/Shutterstock.com METHODS OF REPRODUCTION Check for understanding Question 2 – answer Egg cells are much larger than sperm cells because A sperm are stationary. B sperm provide extra nutrients. C eggs provide protection and nutrients. D eggs provide the majority of genetic information. SciePro/Shutterstock.com Both gametes provide half the required genetic material, while eggs also provide nutrients and protection to support fertilisation and development.  What do we know? Where do babies come from? James Steidl/Shutterstock.com  What do we know? Where do babies come from? Depends on the species! Some offspring are formed through sexual reproduction and are a combination of two biological parents. Some are cloned from one parent through asexual reproduction. James Steidl/Shutterstock.com METHODS OF REPRODUCTION Success measure I can compare the process and outcomes of sexual and asexual reproduction. Not yet Partly Yes Acknowledgements & attributions Labelled images used under licence from Shutterstock.com.  Chapter 3: Reproduction 3B Methods of fertilisation and development Learning intention Content descriptor Describe the form and function of I will be able to describe the key processes of fertilisation reproductive cells and organs in animals and development. and plants, and analyse how the processes of sexual and asexual reproduction enable survival of the species. Success measure Elaborations I can compare the processes, conditions, and outcomes of examining how the reproductive strategies internal and external fertilisation and development. of multicellular animals are related to their environment and the complexity of the organism examining how the number of offspring produced by animals is related to the  Connecting the dots Building on prior knowledge Year 9 Reproduction Methods of Year 7 reproduction have Ecosystems different outcomes Abiotic factors and depend affect how well on the different Year 10 Year 7 a species can structures within Evolution Classification survive in an organism. Similarities in Organisms can be a particular reproductive classified using environment. processes of key traits, different including their species indicate reproductive close processes. evolutionary relationships.  What do we know? Why do salmon swim up dangerous rivers? bierchen/Shutterstock.com: METHODS OF FERTILISATION AND DEVELOPMENT Theory Producing offspring Salmon, humans, and nearly all animals on Earth reproduce sexually. This means that KEY TERMS a sperm cell fertilises an egg cell to produce a zygote. This zygote then develops into a internal fully functional, individual offspring. fertilisation gametes fuse inside Fertilisation can be internal or external: a body Internal fertilisation has a high success rate for each individual gamete, with external fertilisation few offspring produced. gametes fuse outside DID YOU a body KNOW? External fertilisation has a low success rate, but it often results in much larger Salmon use numbers of offspring. external fertilisation, while humans use internal fertilisation. Nixx Photography/Shutterstock.com METHODS OF FERTILISATION AND DEVELOPMENT Theory Internal fertilisation Internal fertilisation usually occurs in terrestrial (land) environments, and protects the KEY TERM gametes from large temperature changes, predators, and drying out. This means the mate an animal’s fertilised zygote has a good chance of survival. partner during sexual reproduction However, it takes a lot of parental energy to find a mate and bring gametes together via specialised reproductive systems. This is why only a small number of offspring are WATCH ME Attracting a mate produced (usually). All mammals use internal fertilisation, as well as most reptiles, birds and insects. DID YOU KNOW? The number of offspring varies significantly across species. E.g. Emperor penguins have one egg at a time which may hatch into one baby offspring, while the common octopus can release Left to right: ruek66, Pete Neisen, yhelfman, and Sandiwild/Shutterstock.com thousands of eggs at once. METHODS OF FERTILISATION AND DEVELOPMENT Theory External fertilisation External fertilisation requires less parental energy. Gametes are released into the KEY TERM (often aquatic) environment with little protection, and rely on water or wind currents migration to bring them together. movement of members of a species to a To increase the group chance of success, external fertilisers can release thousands of different gametes at a time. This produces a large number of offspring. environment WATCH ME This process is often timed with migration or external triggers (e.g. temperature). Coral spawning Most fish and amphibians use external fertilisation, as well as corals and jellyfish. DID YOU KNOW? To increase the likelihood of fertilisation, many species use spawning events where adults meet at the same time and place to release their gametes. Milan Rybar, Albert Beukhof, Coral Brunner, and unoL/Shutterstock.com METHODS OF FERTILISATION AND DEVELOPMENT Theory Stages of development After fertilisation, the next stage of producing offspring is development. KEY TERMS During this time, the zygote grows into a bigger and bigger clump of cells that embryo the stage of development specialise into organs, systems, and recognisable individuals. where the initial zygote has There are two types of development: internal and external. developed into a ball of cells fetus the stage of development external development where an embryo develops specialised structures such as organs and fully formed DID YOU KNOW? hands internal development If a species uses external fertilisation, they will almost always externally develop. But, if they internally zygote embryo fetus baby fertilise, either form of development METHODS OF FERTILISATION AND DEVELOPMENT Theory Internal development Animals that use internal development KEY TERMS are usually larger with more complex internal reproductive systems (e.g. mammals). development offspring develop inside a body They protect and nurture offspring inside gestation the their bodies, before giving birth to live length of time an young with a high survival rate. embryo needs to develop into a fully functional However, the parent is at risk of fatigue, individual within predation, and illness throughout the the body of a parent gestation period and has to use lots DID YOU KNOW? of energy to Mammals use a womb and umbilical cord provide nutrients to the Elephant gestation to provide growing young Elephants have the longest gestation period nutrients, while of all animals: 18-22 months! some spiders carry the young inside them protect their Stalhwerk/Shutterstock.com young internally but use an egg nurse the young after birth. yolk for nourishment instead. METHODS OF FERTILISATION AND DEVELOPMENT Theory External development External development is typically seen in smaller animals, who lay many eggs with a KEY TERMS low survival rate. external development Terrestrial eggs are usually hard-shelled, with all the required nutrients inside. Aquatic offspring develop outside of a body eggs are covered by a jelly-like substance that lets water and nutrients flow in and out. incubation the During incubation some parents try to keep their developing offspring safe (e.g. time it takes an embryo outside a birds) but most species leave them alone, relying on the egg covering for protection. parent’s body to develop into a This leaves offspring highly vulnerable to outside conditions and predators. functional offspring All birds, and most reptiles, fish, amphibians, and insects use external development. WATCH ME Hatching chicken DID YOU KNOW? Only 1/1000 turtle hatchlings reach maturity. Many die in their shells due to predation or high Photosongserm, emirhankaramuk, Oltre lo Specchio, and Matteo Photos/Shutterstock.com tides drowning the eggs. METHODS OF FERTILISATION AND DEVELOPMENT Theory Sum it up higher success rate lower success rate internal: external: Fertilisati inside outside on common with: larger the body the body common with: species species with highly other than mammals specialised that live in aquatic reproductive environments systems higher parental lower parental input input internal: external: higher individual lower individual inside Development outside success rate success rate the body the body lower offspring higher offspring number number METHODS OF FERTILISATION AND DEVELOPMENT Activity Skill Sharpener: Evaluating Comparing parenting styles Follow the instructions to complete the activity Consider the following claims: a. I’d rather be a turtle parent – hide the kids and you’re done! b. Elephants are so bonded to their young, that’s the kind of parent I want to be. c. Salmon parenting for me. Go on an adventure, get fit, and move on with my life. Research the fertilisation and development processes of turtles, elephants, and salmon. 1. Identify two positives and two negatives for each species. 2. Explain which claim you most agree with. ACHIEVEMENT STANDARDS Year 8: Construct evidence-based arguments Year 9: Construct logical arguments based on Year 10: Construct logical arguments based on to support conclusions and evaluate evidence to support conclusions and evaluate analysis claims. claims. of a variety of evidence to support conclusions METHODS OF FERTILISATION AND DEVELOPMENT Activity Example answer Question 1 Turtle Elephant Salmon Pros Internal fertilisation means Internal fertilisation and Mass spawning events bring increased chance of gametes development means the baby is gametes close together to forming offspring. protected the increase chances of whole time. fertilisation. External development means the adult doesn’t have to do Parental care is shared by the Large numbers of offspring anything after eggs are laid. whole herd. develop since so many were fertilised. Cons Low survival rate of Long gestation period (22 After spawning, many adults hatchlings due months) puts a huge strain on die due to weakness and to predation. the carrying parent. predation. Safety relies on the parent Very low numbers of offspring Developing salmon are at high Question 2 finding suitable nest site to produced. risk of predation, and only a hide the eggs. This can be small percentage reach Being a threatened turtle parent seems by snakes to be the best option. They don’t or birds. havematurity. to put as much effort in as elephants or salmon, and the adults are more likely to survive. Although it is likely that a lot of the offspring will die, the overall outcome is multiple offspring and a healthier parent. METHODS OF FERTILISATION AND DEVELOPMENT Check for understanding Question 1 Higher parental care during development is generally associated with A external development. B higher offspring numbers. C lower protection from predation. D higher chances of offspring survival. METHODS OF FERTILISATION AND DEVELOPMENT Check for understanding Question 1 – answer Higher parental care during development is generally associated with A external development. B higher offspring numbers. C lower protection from predation. D higher chances of offspring survival. The more involved a parent is, the more likely an offspring is to survive through development. METHODS OF FERTILISATION AND DEVELOPMENT Check for understanding Question 2 Which statement is correct? A External fertilisation does not involve gametes. External development only occurs after external B fertilisation. Internal development requires specialised reproductive C systems. Internal fertilisation occurs only in terrestrial D environments for mammals. METHODS OF FERTILISATION AND DEVELOPMENT Check for understanding Question 2 – answer Which statement is correct? A External fertilisation does not involve gametes. External development only occurs after external B fertilisation. Internal development requires specialised reproductive C systems. Internal fertilisation requires terrestrial environments and D mammals. The more complex and specialised an organism's systems, the more likely they are to use internal development processes.  What do we know? Why do salmon swim up dangerous rivers? bierchen/Shutterstock.com:  What do we know? Why do salmon swim up dangerous rivers? To produce offspring in the safer breeding grounds upstream. Salmon use external fertilisation by releasing eggs and sperm during mass spawning events. This migration weakens the parents and risks death by bear, but it significantly increases the chances of reproductive success. bierchen/Shutterstock.com: METHODS OF FERTILISATION AND DEVELOPMENT Success measure I can compare the processes, conditions, and outcomes of internal and external fertilisation and development. Not yet Partly Yes Acknowledgements & attributions Labelled images used under licence from Shutterstock.com.  Chapter 3: Reproduction 3C Human reproduction Learning intention Content descriptor Describe the form and function of I will be able to identify the role of different reproductive organs in reproductive cells and organs in animals the human reproductive system. and plants, and analyse how the processes of sexual and asexual reproduction enable survival of the species. Success measure Elaboration I can describe how the human reproductive organs work examining how the male and female together to produce offspring. reproductive organ structures work collectively as a system  Connecting the dots Building on prior knowledge Year 9 Reproduction Humans are Year 8 placental mammals Body systems with specialised Organs are reproductive organs specialised that work together Year 7 structures that to produce Year 10 Classification have specific offspring. Genetics Organisms can be functions within Offspring classified using a system. inherit a random key traits, combination of including their parental traits reproductive during sexual processes. reproduction.  What do we know? What happens during puberty? UfaBizPhoto/Shutterstock.com: HUMAN REPRODUCTION Theory In the beginning We all start the same way: an egg fertilised by a sperm, growing into a bundle of cells. KEY TERMS This bundle eventually becomes a fully functional person, facial hair and all. hormones chemicals that There are no physical differences between males and females in the first 12 weeks stimulate specific organs of development. However, things change from then on. and/or cells into action Hormones trigger changes in development, depending on the sex: gonad an organ that produces gametes; testes or ovaries oestrogen hormone involved in the development of female characteristics testosterone hormone involved in the development of male characteristics HUMAN REPRODUCTION Theory Male reproductive organs Testosterone acts on an embryo to develop male reproductive organs. Some of the male reproductive organs sit outside the body, like the penis and testes. vas deferens: provide a pathway for sperm to reach the penis prostate: produces the fluid that transports sperm (seminal fluid - also known as semen) penis: carries the seminal fluid with the sperm and deposits it in the vagina testes: produce the sperm HUMAN REPRODUCTION Theory Female reproductive organs Oestrogen acts on an embryo to develop female reproductive organs. These organs sit inside the body. fallopian tubes: environment for fertilisation; a pathway from the ovary to the uterus uterus: environment for the developing fetus ovaries: produce and store the eggs endometrium: allows for implantation of a zygote cervix: connects the uterus and the vagina vagina: connects the uterus and cervix to the outside of the body HUMAN REPRODUCTION Theory Puberty The development of reproductive organs doesn’t stop once you are born; the human KEY TERMS body can only reproduce once the reproductive organs are fully functioning, and this puberty occurs during puberty. a period where the body undergoes changes Changes to the reproductive system are made by hormones, which affect different for parts of the body: sexual maturity DON’T GET TRICKED Testosterone Oestrogen All humans have testosterone and Key changes during puberty oestrogen. Males tend to have more external reproductive organs get hips widening testosterone and females tend to larger menstruation have more male gamete (sperm) production oestrogen. breast growth voice deepening hair growth hair growth acne acne HUMAN REPRODUCTION Theory Ovulation In the ovaries, puberty triggers the ovulation KEY TERMS maturation of eggs (female gametes). ovulation Generally, a new egg matures and is the release of a mature egg from released each month. It usually survives Egg fertilised by an ovary sperm? for around 24 hours. Yes No pregnancy the period of This event is known as ovulation, and is time between fertilisation and when fertilisation is most likely to occur. embryo forms no embryo birth forms menstruation There are two pathways for an egg: shedding of the endometrium pregnancy menstruation lining in the uterus during the menstrual cycle DID YOU KNOW? More than one egg can be released during ovulation. This is one way we get twins and triplets. HUMAN REPRODUCTION Theory Menstruation Ovulation is one part of a 24 to 40 day WATCH ME menstrual cycle. Learn more about menstruation from For most of the cycle, the endometrium 0:00 to 3:56. lining in the uterus thickens. This is in preparation to host an embryo. DID YOU KNOW? Many things can If no embryo is produced (if fertilisation disrupt the does not occur during ovulation) then the menstrual cycle, such as stress, lining is shed out of the vagina. extreme weight loss, excessive This is known as menstruation, or having exercise, or reproductive a period. system disorders. DON’T GET TRICKED People with female reproductive organs can start ovulating (and can therefore fall pregnant) before getting their first period. HUMAN REPRODUCTION Theory Placental development Humans are placental mammals. This KEY TERMS means that if an egg is fertilised, the fetus developing fetus is nourished in the unborn offspring that develops womb by the placenta. from an embryo The placenta begins developing as soon placenta as the embryo reaches the endometrium. a flattened organ in the uterus It remains attached to the mother via the which nourishes a fetus via the uterus and connected to the fetus via an umbilical cord umbilical cord. DON’T GET TRICKED Marsupial mammals such as kangaroos and koalas, also develop a placenta, but it nourishes the fetus for a much shorter amount of time. HUMAN REPRODUCTION Theory Human gestation Thanks to the placenta, humans have a relatively long gestation time – nine months. WATCH ME This is broken into three x three-month stages known as the first, second, and third Learn about the stages of gestation trimesters. from 0:16 to 3:32. A long gestation can be a good and a bad thing: Pros Cons The fetus has more time to develop, Mothers need to invest a lot of time which means and energy into growing the fetus, large and well-developed babies which means are birthed more food needs to eaten the baby has a higher chance mother experiences fatigue. of survival. A larger fetus results in the mother being larger and less mobile a riskier birth for the mother. HUMAN REPRODUCTION Theory The trimesters finish at birth The first trimester of pregnancy is the most action packed: the most changes take place in these first 12 weeks. During the second and third trimesters the baby and its organs continue to develop until the baby is ready to be born. Pregnancy tissue from the first trimester 5 weeks 6 weeks 7 weeks 8 weeks 9 weeks This tissue will form The embryo is within Cells that will form Embryo and At this stage the into the placenta and the sac but is too the heart develop surrounding tissue fetus is sometimes the sac where embryo small to see with and ‘beat’. continues large enough to see develops. the naked eye. to develop. within the sac. Embryo is a collection of cells surrounded by supportive tissue. Dr. Joan Fleischman MD, MPA/MYA Network HUMAN REPRODUCTION Theory Sum it up Human reproduction systems specialise into male female produce sperm produce egg travels travels from from testes penis vagina fallopian ovaries tube fertilis not ed fertilised uterus menstruation HUMAN REPRODUCTION Activity Skill sharpener: Communicating Fetus growth stages timeline The size of a developing fetus at each growth stage is often described using fruit to give a visual comparison. For example, at 12 weeks (end of first trimester) the fetus is a similar size to a passionfruit. Designer things/Shutterstock.com Continues ACHIEVEMENT STANDARDS → Year 8: Select and use language and text Year 9: Select and use content, language and Year 10: Select and use content, language and features appropriately for their purpose text features effectively to achieve their text features effectively to achieve their when communicating their ideas, findings purpose when communicating their ideas, purpose when communicating their ideas, and arguments to specific audiences. findings and arguments to specific findings and arguments to diverse audiences. HUMAN REPRODUCTION Activity Skill sharpener: Communicating Follow the instructions to complete the activity. Research and then create a timeline that compares the size of the fetus over a pregnancy to common items (such as fruit, sporting equipment and stationary). Include in your timeline the trimesters and their associated weeks images or drawings of each item labels of the week/s each item relates to (not every week of development needs to be included) label the change from embryo to fetus a description of any interesting or important development stages (i.e. week 9). HUMAN REPRODUCTION Activity Example answer Trimester 1 Trimester 2 Trimester 3 last period–12 weeks 13–26 weeks 27–40 weeks Week 5 Week 9 Week 12 Week 14 Week 20 Week 24 Week 28 Week 36 Week 38 peppercorn cherry plum lemon capsicum cabbage cauliflo melon jackfruit wer Cells that Cells The fetus Hair The The The The fetus’ Lungs are will form that has follicles mother fetus fetus head may fully systems will begin to can feel may be can hear drop down developed started and form develop. the able to things into the. to structures arms, fetus survive outside pelvic develop. elbows, develop moving prematur the area in and into a around. e birth. body. preparatio nipples male or n for Left to right: Suto develop. Norbert Zsolt, MarcoFood, female. Kyselova Inna, Maks Narodenko, paulista, Kaiskynet Studio, olgsera, Zeeking, and birth. MacMontree/Shutterstock.com HUMAN REPRODUCTION Check for understanding Question 1 Oestrogen A is only found in females. B acts on males during puberty to produce sperm. C triggers changes to the gonad tissues to form testes. D is involved in the development of female reproductive organs. HUMAN REPRODUCTION Check for understanding Question 1 – answer Oestrogen A is only found in females. B acts on males during puberty to produce sperm. C triggers changes to the gonad tissues to form testes. D is involved in the development of female reproductive organs. Oestrogen is a hormone vital for the development of ovaries and other female reproductive organs. HUMAN REPRODUCTION Check for understanding Question 2 During fertilisation, the pathway of sperm is fallopian tube → uterus → penis → vagina → vas deferens → A testes vas deferens → testes → penis → vagina → fallopian tube → B uterus testes → vas deferens → penis → vagina → uterus → fallopian C tube fallopian tube → uterus → vagina → penis → vas deferens → D testes HUMAN REPRODUCTION Check for understanding Question 2 – answer During fertilisation, the pathway of sperm is fallopian tube → uterus → penis → vagina → vas deferens → A testes vas deferens → testes → penis → vagina → fallopian tube → B uterus testes → vas deferens → penis → vagina → uterus → fallopian C tube fallopian tube → uterus → vagina → penis → vas deferens → D testes The male gametes, sperm, are formed in the testes. They move from the male reproductive system into the female reproductive system where they may fertilise an egg in the fallopian tube.  What do we know? What happens during puberty? UfaBizPhoto/Shutterstock.com:  What do we know? What happens during puberty? During puberty, the human body matures and finishes developing its sexual reproductive system. Through puberty, the body is able to reproduce. This comes with noticeable changes such as voice deepening in males, menstruation in females, and extra hair growth for everyone! UfaBizPhoto/Shutterstock.com: HUMAN REPRODUCTION Success measure I can describe how the human reproductive organs work together to produce offspring. Not yet Partly Yes Acknowledgements & attributions Images: Slide 13: Image used with permission from Dr. Joan Fleischman MD, MPA/MYA Network Labelled images used under licence from Shutterstock.com.  Chapter 3: Reproduction 3D Plant reproduction Learning intention Content descriptor Describe the form and function of I will be able to identify the reproductive structures of plants. reproductive cells and organs in animals and plants, and analyse how the processes of sexual and asexual reproduction enable Success measure survival of the species. I can compare the structures used for sexual and asexual Elaborations reproduction in plants. examining how the male and female reproductive organ structures work collectively as a system identifying and comparing sexual and asexual reproductive strategies in plants  Connecting the dots Building on prior knowledge Year 9 Reproduction Plants have Year 8 different Body systems structures to Organs are specialised support Year 7 structures that reproductive Year 10 Classification have specific processes. Genetics Organisms can be functions within Offspring classified using a system inherit a random key traits, combination of including their parental traits reproductive during sexual processes. reproduction.  What do we know? How do chocolate trees make more chocolate trees? Kehinde Olufemi Akinbo/Shutterstock.com PLANT REPRODUCTION Theory Methods of reproduction Plants can reproduce sexually or asexually, depending on the structures they have. DID YOU KNOW? Many plants can even do both – like the cacao tree that chocolate comes from! Most plants can reproduce sexually AND asexually. For no gametes needs gametes example, the cacao, daffodils, strawberries, and potatoes can do both. requires requires Environmental asexual Method sexual conditions often special special determine which structures structures method is used. produces creates clones variation Nandalal Sarkar/Shutterstock.com Varts/Shutterstock.com PLANT REPRODUCTION Theory Sexual reproductive systems The sexual reproductive systems KEY TERMS of plants are more complex, as stamen male reproductive they need to produce and structure in fertilise gametes. flowers, including the The male reproductive system in anther and filament plants pollen is known as the stamen. It a fine powder, containing male contains pollen, which houses gametes the male gametes produced by the pistil female anther. It is often found at the reproductive tip of the filament. structures in flowers, The female reproductive system including DON’T GET the stigma, TRICKED ovary, is known as the pistil. It has and style Gametes have the same function in structures to receive the pollen plants and and bring it to the ovary, which animals, but different contains the female gamete. structures PLANT REPRODUCTION Theory Pollination To transfer the male gamete (in pollen) to KEY TERMS a female gamete, plants need help pollinator from pollinators. agents of pollination that actively These can be insects, wind, water, or transfer pollen passing animals that dislodge pollen from between plants the filament and anther, and then carry it pollination transfer of away to find a stigma (the opening of the pollen from anther to stigma female reproductive system). for fertilisation DON’T GET TRICKED This pollination can occur between plants of the same species or within the The ovule contains the female plant same plant. ‘egg’ and the pollen grain Flowers play a crucial role in this process, contains the male plant ‘sperm’. The attracting pollinators with their color, ovule and pollen scent, and nectar. grain structures are not gametes themselves. PLANT REPRODUCTION Theory Video – Pollinators Watch this clip to learn about different pollinators. https://www.youtube.com/watch?v=Dfvyoir _SCY&t=98s Watch from 1:38 to 5:52 PLANT REPRODUCTION Theory Self- and cross- pollination The two types of pollination are called self-pollination and cross-pollination. WATCH ME Types of pollination DID YOU KNOW? Humans manipulate pollination to increase the chances of growing particular types of plants – like food crops. Self-pollination Cross-pollination pollen from parent plant lands on pollen from one plant transfers to its own stigma, or stigma of another plant’s stigma another flower on the same parent new plants have a mix of genetics plant from new plants are genetically similar each parent to parent PLANT REPRODUCTION Theory Fertilisation occurs after pollination PLANT REPRODUCTION Theory Seeds form after fertilisation Like animals, plant fertilisation forms a zygote with a unique combination of parental traits. This zygote develops into a seed around the embryo: PLANT REPRODUCTION Theory Asexual reproductive structures are simple Structur Description Examples WORDOLOGY e The ‘a’ in ‘asexual means bulb consists of modified leaf layers, onions ‘without’ found underground as food and seed in Greek. daffodils storage So, ‘asexual’ means ‘without sex’. rhizome piece of stem growing horizontally bamboo DID YOU KNOW? underground, creating new shoots ginger Humans often propagate plants asexually by using runner stem growing horizontally on the strawberries ‘cuttings’ – top of the soil, sprouting new pieces seedlings mint of the plant that can grow roots and shoots. This can spore reproductive structures released ferns be done to produce from the surface of plants and more fungi mushrooms cacao trees. tuber swollen underground root potatoes containing nutrients to sprout buds dahlias Top to bottom: nnattalli, johan kusuma, Volodymyr Nikitenko, Kichigin, and Kishore J/Shutterstock.com PLANT REPRODUCTION Theory Plants can develop with or without a seed KEY TERMS The development of adult plants starts differently depending on how they are formed. germination Sexual reproduction Asexual reproduction development of a seed or spore into Goes through the seed → germination Begins as a plant segment, bypasses a seedling phase, uses methods such as wind to fruiting and seed dispersal, and sprout the root disperse seeds. will begin to sprout. and stem growth forming the starting shoot of the plant WATCH ME Growing tomato from cuttings DID YOU KNOW? Seeds aren’t always formed from fruits. Seeds are produced by some non-fruiting plants as well. PLANT REPRODUCTION Theory Sum it up Plant reproduction no gametes gametes asexual sexual clones variation structures structures include include bulb runner spore stamen pistil pollination PLANT REPRODUCTION Activity Skill Sharpener: Questioning and predicting Predicting reproduction outcomes Follow the instructions to complete the activity 1. Draw two diagrams of plant reproduction to show the structures involved for: a. Plant A, which uses sexual reproduction to form offspring. b. Plant B, which uses a method of asexual reproduction to form offspring. 1. Predict the impact of pollinators on the reproduction rates of plants A and B. a. Outline this as a testable hypothesis. b. Identify the evidence that would support or refute the hypothesis. c. Add labels to your diagrams to justify your predictions. ACHIEVEMENT STANDARDS Year 8: Plan and conduct safe, Year 9: Plan and conduct safe, reproducible Year 10: Plan and conduct safe, valid and reproducible investigations to test investigations to test or identify reproducible investigations to test relationships and explore models. relationships and models. relationships or develop explanatory models. PLANT REPRODUCTION Activity Example answer Question 1a Question 1b Pollen is transferred from stamen to stigma Stem forms horizontally underground, new leaf growth shoots up as a clone plant. Continues PLANT REPRODUCTION Activity Example answer Question 2a Question 2c If a plant A only has sexual reproductive structures, then reproduction will only occur in the presence of pollinators. If plant B only reproduces asexually, then pollinators would not affect its Question 2b reproduction rate. The hypothesis would be supported if Plant A produces offspring when there are pollinators, but does not produce offspring when there were none. If Plant B produced offspring without the presence or absence of pollinators, this would further support the hypothesis. PLANT REPRODUCTION Check for understanding Question 1 Asexual reproduction produces clones of the parent through A only runners. B relying on wind and water. C moving pollen through the stigma. D specialised structures such as bulbs. PLANT REPRODUCTION Check for understanding Question 1 – answer Asexual reproduction produces clones of the parent through A only runners. B relying on wind and water. C moving pollen through the stigma. D specialised structures such as bulbs. There are many types of asexual reproduction, each utilising different structures such as runners, spores, and tubers. PLANT REPRODUCTION Check for understanding Question 2 The likely function of flowers on sexually reproducing plants is Floridafan/Shutterstock.com A to protect the pollen from falling off. B to encourage pollinators to visit the plant. C to warn passing animals to avoid the plant. D to nourish the developing seed after fertilisation. PLANT REPRODUCTION Check for understanding Question 2 – answer The likely function of flowers on sexually reproducing Flowers are plants is often brightly coloured and/or scented, attracting pollinators such as Floridafan/Shutterstock.com insects and birds to come to the A to protect the pollen from falling off. plant and B to encourage pollinators to visit the plant. dislodge the pollen. C to warn passing animals to avoid the plant. D to nourish the developing seed after fertilisation.  What do we know? How do chocolate trees make more chocolate trees? Kehinde Olufemi Akinbo/Shutterstock.com  What do we know? How do chocolate trees make more chocolate trees? Chocolate is made from the seeds of the cacao tree. New trees can be made through sexual reproduction: fertilising a zygote, which becomes a seed, and eventually (if we don’t eat it), another tree. Humans can also use cuttings of the cacao tree to grow more cacao. Kehinde Olufemi Akinbo/Shutterstock.com PLANT REPRODUCTION Success measure I can compare the structures used for sexual and asexual reproduction in plants. Not yet Partly Yes Acknowledgements & attributions Labelled images used under licence from Shutterstock.com.