Adaptations for survival 1 EL: To see what we already know about adaptations and begin learning about different types of adaptations Activity • Complete first column of the “Adaptations Biq Questions” worksheet • Put any other questions you have about adaptations at the end • Hand in when you are done (don’t keep it!!!) – you’ll get it back at the end to see how much you have learnt! What is survival? Organisms that are considered “successful” at surviving in their environment: 1.Survive to reproductive age 1.Reproduce and have enough young to ensure survival of the next generation Adaptations • • An adaptation is a feature that seems to equip an organisms for survival in a particular habitat. Adaptations can be structural, behavioural or physiological. Examples of Adaptations Type of Adaptation Structural Behavioural Physiological Animal Example Plant Example Structural Adaptations • Features of the shape and structure of the organism that help it to survive in it’s environment – Think of one example in an animal and one example in a plant and write it down in your table. Structural Adaptations Behavioural Adaptations • Behaviours undertaken by an organism that help it to survive in it’s environment • Think of one example in an animal and one example in a plant and write it down in your table Behavioural Adaptations Physiological Adaptations • Features of the organisms internal physiology (e.g. body temperature, water balance, heart rate, blood pressure ect) that help it to survive in it’s environment – Think of one example in an animal and one example in a plant and write it down in your table Physiological Adaptations activity/homework • • • • Page 291, qu 19, 22 Page 292, Biochallenge qu 5 Page 295 qu 11 Animal adaptations worksheet (to be handed in next lesson) Reflection • From completing the big questions, how would you rate your pre-existing knowledge of adaptations from 1 (terrible) to 10 (very good)? Adaptations for Survival 2: Physiological EL: To begin learning about physiological adaptations, focusing on homeostasis Homeostasis • Organisms cannot survive unless they are able to control the internal environment of their body, despite continual changes in their surroundings. • Homeostasis = The maintenance of a constant internal environment despite changes in the external environment. Homeostasis What needs to be kept within narrow limits? M.I.T.G.O.W.B + pH + wastes • • • • • • • • Metabolites (eg blood glucose concentration) Ions (eg salts) Temperature Gases (eg CO2 and O2) Osmolarity (ie water balance) Wastes (e.g. urea) Blood Pressure pH Stimulus-response model Stimulus Receptor Transmission nerves Control centre Response Effector Transmission – nerves or hormones Stimulus-response model example Negative Feedback Increase in blood CO2 Receptor in arteries and veins Transmission nerves Respiratory centre in brain Negative feedback – response counteracts the stimulus More CO2 exhaled Respiratory muscles in lungs Transmission nerves Watch click view movie Activity • Individually or in groups of up to 4 people, use the stimulus-response model to explain homeostasis. You can do this by either: – Performing a role play – Writing and performing a song or rap – Creating and performing an interpretive dance – Creating a poster and presenting it to the class – To be finished and presented next lesson Reflection and Homework • What have you learnt about homeostasis? • Homework: Quick check qu: 1-4 pg 301 Adaptations for Survival 3: Physiological EL: To demonstrate our understanding of homeostasis and to learn about the involvement of the nervous system Activity • Present your homeostasis piece to the class The nervous system • This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli. • Maintains homeostasis by detecting change and coordinating the action of effector organs • Responsible for unidirectional, fast communication by electrical impulses The Central Nervous System (CNS) Consists of the brain and spinal cord Cerebrum brain Cerebellum Medulla Oblongata Spinal Cord The peripheral nervous system (PNS) • Nerves extending out to the rest of the body from the CNS • Includes all sensory neurons, motor neurons, and sense organs Nerve cells: Neurons • The basic functional unit of the nervous system. • Send impulses to and from the CNS and PNS and the effectors (muscles/glands) Nerve cells: Neurons Structure Description Function Soma/cell body The control center of the neuron Directs impulses from the dendrites to the axon Nucleus Control centre of the soma Tells soma what to do Dendrites Highly branched extensions of the cell body Receive and then carry information towards the cell body Axon Extension of the cell body Carries information away from the cell body Myelin sheath Insulating layer around axon made of Schwann cells Increases speed of impulse Nodes of Ranvier Gaps between Schwann cells. Saltatory conduction – i.e. speed of an impulse is greatly increased by the message ‘jumping’ the gaps Synapse Gap between axon or one neuron and dendrite of another Communication between nerve cells Types of Neurons Affector/sensory neuron: • Receive incoming stimuli from the environment to CNS • located near receptor organs (skin, eyes, ears). Connecting neuron/ interneuron: • Relay messages between other neurons such as sensory and motor neurons. • Usually found in brain and spinal cord. Effector/motor neuron: • Carry impulses from CNS to effectors to initiate a response • located near effector (muscles and glands) Types of Neurons Fun Fact: Where can the largest cells in the world be found? The giraffe’s sensory and motor neurons! Some must bring impulses from the bottom of their legs to their spinal cord several meters away!! Types of receptors Mechanoreceptors respond to mechanicalenergy (e.g. ear drum) Thermoreceptors respond to heat or cold (e.g. nerve endings in skin) Electromagnetic receptors respond to electromagnetic energy (e.g. ampullae of Lorenzini in sharks) Photoreceptors respond to visible light and UV radiation (e.g. eyes). Chemoreceptors respond to chemical stimuli (e.g. olfactory) Video • http://www.youtube.com/watch?v=xRkPNwq m0mM • http://www.youtube.com/watch?v=iNgGKSNiNw Activities • Complete Quick check qu 5&6 pg 308 • Complete Chapter Review Question 3 on page 237 Reflection and homework • How did the group activity help you to understand homeostasis better? • What did you learn about the nervous system today? Homework: Complete any unfinished questions Adaptations for Survival 4: Physiological EL: To learn how the endocrine system is involved in homeostasis, as well as how animals regulate temperature Endocrine System • Uses chemical signals for cell to cell communication • Coordinates the function of cells • Response to an endocrine signal occurs within minutes to hours Endocrine System Endocrine glands Release hormones into the bloodstream. Hormones Chemicals released in one part of the body that travel through the bloodstream and affect the activities of cells in other parts. body. Endocrine system Controlling Glucose levels • Your cells need an exact level of glucose in the blood. • Excess glucose gets turned into glycogen in the liver • This is regulated by two hormones produces by the pancreas: insulin and glucagon Glycogen If there is too much glucose in the blood, insulin converts some of it to glycogen Glucose in the blood Glycogen If there is not enough glucose in the blood, glucagon converts some glycogen into glucose. Glucose in the blood Activity • Complete quick check qu 7 pg 308 • Complete “Nerves and Senses” Worksheet Detecting temperature change • Most organisms have an optimal internal and/or external temperature range – E.g. Humans: internal temp approx 37oC – E.g. coral: external temp approx 26oC • Why? Optimal temperature for enzymes and other internal processes. Above or below can lead to lower functioning and possibly even death. Detecting temperature change: Humans • External temp change detected by receptors in skin – one type for detecting cooling, another for heating • Internal temp receptors found deep within body – mostly within brain, near spinal cord, around large veins and in digestive system • Affector (sensory neurons) relay the information to the hypothalamus – the temp control centre of the body Maintaining core temperature • Interaction of nervous and endocrine systems • Maintenance requires heat gain balancing heat loss – done in a number of ways Losing heat • Heat can be lost through radiation , conduction, convection and evaporation Losing heat Losing heat • Organism may also undertake behaviours to lower temperature, such as: – Licking arms or legs to increase evaporative cooling – Increasing the amount of surface area exposed Gaining heat • Hypothalamus initiates heat generation or reduction of heat loss • Heat can be generated through: – muscle contractions converted to heat energy through shivering – metabolic heat generation involving the pituitary gland • Heat loss can be reduced though: – Constriction of blood flow to the skin (i.e. vasoconstriction) – Piloerection of hairs on the skin Gaining heat • Organism may also undertake behaviours to lower temperature, such as: – Moving around (e.g. jumping up and down) – Sheltering, putting on extra clothes, putting heater on – Huddling, reducing surface area exposed Surface Area to Volume Ratio • In a cold temperature surface area exposed to the cold air is reduced. • On a very hot day, surface area is increased so that more body heat is lost. Cat on a hot day – flattens out in a shady location, increasing its SA:V ratio Cat on a cold day – curls up to reduce its SA:V ratio Big or small? • Do you think big or small animals stay warm more easily? Write it down and why. • Take a look at page 314 and see if you were correct! Animals adapted to the cold • If the water in cells freezes, the cells are killed as ice crystals pierce the plasma membrane. • Pure water freezes at 0˚C, but cytosol with dissolved materials in it has a lower freezing point, eg. Some salty solutions freeze at -18˚C. • Emperor penguins have number of adaptations to equip them for survival in freezing conditions. These include: Animals adapted to the cold • A high metabolic rate - convert chemical energy in their food into heat energy. • This heat is retained by excellent insulation; layers of fat underneath the skin and a thick covering of feather layers. • They huddle together to reduce their surface areas exposed to the cold wind. • Circulation changes to slow heat loss through the feet. • Counter current heat exchange in their flippers. • Large body size to reduce SA:V ratio. Ectothermic vs Endothermic • Ectotherms: depend on external sources of heat to generate body heat (what are some egs?) • Endotherms: generate their own body heat through internal chemical reactions – Interesting fact: 80% of the energy mammals get from their food is used to maintain core body temperature! Activity • quick check qu 8-12 on pg 317 • Biochallenge pg 336 • chapter review qu 2, 5, 7 • “Thermoregulation in mammals” worksheet Reflection and homework • What did you learn about thermoregulation today? • Homework: Complete any unfinished questions. Adaptations for Survival 5: Physiological EL: To demonstrate thermoregulation Activity • In groups of 3-4, complete activity 8.1 “The skin and temperature control” • Complete report INDIVIDUALLY on to sheet and hand in Reflection and homework • What did this experiment confirm or contradict about thermoregulation today? Homework: Complete prac report Physiological Adaptations for Survival 6 EL: How aquatic animals and plants thermoregulate Thermoregulation in aquatic mammals • Water is a much greater thermoconductor than air: – i.e. heat is lost to water much faster than it is to the air • However, aquatic mammals, such as whales, dolphins and seals, are endothermic and breathe air • In order to thermoregulate in water, aquatic mammals have special adaptations that help them to survive Thermoregulation in aquatic mammals 1. Blubber: insulating layer of fat below the skin and sometimes around internal organs. Can be up to 50cm thick. Thermoregulation in aquatic mammals 2. Fur: Seal, sea lions and otters have a dense (thick) layer of fur that traps a layer of air next to the skin so that their skin never gets wet. Thermoregulation in aquatic mammals 3. Countercurrent exchange: Involves vascular tissue in fins, flukes, tails and other appendages. • An outgoing artery from the body carrying warm blood transfers its heat to an incoming vein carrying cold blood. • This reduces amount of heat lost through skin and ensures blood returning to the body is at the right temperature Thermoregulation in aquatic mammals Thermoregulation in plants • Plants in a hot environment thermoregulate through: – Radiating heat to the environment – Transpiration of water - evaporative cooling (like sweating) – Leaf shape – increasing leaf edge to surface area ratio Thermoregulation in plants cont… – Protecting enzymes using heatshock proteins – Leaves orientating themselves away from the direct rays of the sun (e.g. Eucalypts) – Structural adaptations such as the ability to hold water (e.g. succulents, bottle trees) – Reducing leaf surface area by dropping leaves Activity • “Control of body temperature” worksheet • quick check questions 13-18 on pg 322, & 1921 on pg 325 • chapter review questions 6&8 on pg 339 Reflection • What did you learn about thermoregulation in aquatic mammals and plants today? Homework: Complete any unfinished questions/worksheets Adaptations for Survival 7: Physiological EL: To investigate how animals and plants osmoregulate Why osmoregulation is important • Osmoregulation = maintenance of constant internal salt and water concentrations in internal fluids • Controlling water balance is important to ensure the cells of the body are in equilibrium – Too much water outside cells and the cells will absorb it, possibly exploding – Too little water inside cells and the cells will release water, possibly collapsing Water balance in vertebrates • Kidneys eliminate nitrogenous waste and control water balance in all vertebrates • The basic structure that filters nitrogenous waste from blood is the loop of Henle . • The differences in the length of the loop of Henle are related to the differences in need to conserve water. Water balance in vertebrates • The longer the loop of Henle, the more water can be reabsorbed into the bloodstream, and the more concentrated their urine. • Beaver – lives in fresh water, has a very short loop of Henle and produces weak urine compared to its body fluids. • Kangaroo rat – lives in desert, has a very long loop of Henle and produces concentrated urine compared to its body fluids. Water balance and blood pressure • As water balance varies, so too does blood pressure – Increased water = increased blood pressure (and vice versa) • Two major hormones involved are antidiuretic hormone (ADHD or vasopressin) and renin Desert animals Abiotic factors in the desert environment include: • • • • • • Low rainfall Low humidity High daytime temperatures Low night temperature Low soil moisture Intense solar radiation Organisms struggle to: • Find free water • Stay hydrated • Keep cool What behavioural changes would you need to make to survive in the desert? Camel adaptations Camels can survive for several days without drinking water, even in very high temperatures. They have several special features that enable them to survive the extreme conditions they encounter in the desert. These adaptations include: • A fluctuating core temperature, can be as low as 34˚C & as high as 41˚C • Large roundish body, fat concentrated in the hump & extremely thin legs • Can drink over 150L of water when available to rehydrate quickly • A slower metabolic and breathing rate in summer • Blood with a high water content • Extremely dry faeces • Lying down for long periods during day • Urinating down its legs Water wise – the spinifex hopping mouse • It does not need to drink. The seeds, insects and roots that it eats provide enough water to live on. • It has no sweat glands. • Its droppings are almost completely dry. • Its kidneys waste very little water (its urine is one of the most concentrated of any mammal). • It is active at night (when it is cooler). • It lives together in burrows (this increases the humidity in the burrow and reduces water loss). • It even uses metabolic water efficiently. • Mothers produce very concentrated milk (and drink the urine of their young). Water balance in plants • Plants are 90-95% water • Up to 98%of water absorbed by a plant is lost through transpiration • They cannot move around to search for water Water balance in plants • Features that help them to obtain and retain water including – Waterproof cuticle on leaves – Sunken stomata – Rolled up leaves – Large vacuoles for water storage (eg cacti and succulents) – Cylindrical leaves (e.g. hakea) – No leaves (e.g. acacia) Activity • quick check qu 22-24 on pg 330 • quick check qu 25-30 on pg 335 • chapter review qu 9-15 on pg 338-40 Reflecton and homework • What did you learn about osmoregulation in animals AND plants today? • Homework – finish activity 10.3 and any questions Adaptations for Survival 7: Physiological EL: To demonstrate water balance in animals Activity • “Water balance in animals” experiment Reflection and Homework • What did your experiment conclude about osmoregulation in animals today? Homework: Complete prac report Adaptations for Survival 8: Behavioural EL: To explore innate behaviours Starting to think about behaviours.. Abiotic factors in these polar environments include: • • • • Freezing temperatures Gale force winds Variable sunlight with seasons Blizzards Organisms struggle to: • • • • • Stay warm Ensure cells don’t freeze Gather enough food Avoid predation Successfully rear offspring What behavioural changes would you need to make to survive in Antarctica? Ethology • The study of animal behviour • What are some behaviours that ethologists might study? What are innate behaviours? • Behaviour that is essentially the same in all members of a species and which can occur without an individual having had prior experience of the behaviour • What are some human examples of innate behaviours? • What are some examples of innate behaviours in other animals? Video • http://www.youtube.com/watch?v=UEO35Dq 1rA8 Development of innate behaviours • Innate behaviours are not necessarily fully developed at birth and may be modified by learning – E.g. swimming and diving in Australian fur seal pups – E.g. feeding in laughing gull chicks Activity – simple innate behaviour • With a partner, move out of direct light • Look into your partner’s eyes and note down the size of their pupil • Shine a light into your partner’s eye BRIEFLY and note down what happens • Explain how this innate behaviour relates to the function of the eye and why it is important Innate vs learned behaviours Activity • Work in groups of 4. Each group will be assigned one type of innate behaviour from pg 344-356 of the text book. • In your group, you have 5 minutes to work out the best way to demonstrate the behaviour to the rest of the class in a way that helps them learn more about it (i.e. hangman may not be your best option) • You have a max of 3 minutes to present your “lesson” Activity • Demonstrate simple innate behaviour Reflection and homework • What did you learn about innate behaviours today? Homework: quick check qu 1-4 pg 357 Adaptations for Survival 10: Behavioural EL: To explore learned behaviours Learned behaviours • Behaviours that develop or change as a result of experience Innate vs learned behaviours Conditioning • Classical conditioning defined by Ivan Pavlov – Learning through reward (or punishment!) – http://www.youtube.com/watch?v=hhqumfpxuzI – http://www.youtube.com/watch?v=Eo7jcI8fAuI • Operant conditioning – Learning through trial and error – http://www.youtube.com/watch?v=I_ctJqjlrHA Habituation • Response to a repeated stimulus gradually decreases – http://www.youtube.com/watch?v=Kfu0FAAu-10 • Why is this important in nature? • So that animal isn’t wasting energy responding to non-threatening stimulus Insight • Animal applies previous experience to the solution of a new problem – http://www.youtube.com/watch?v=XcMI1NAew3 o – http://www.youtube.com/watch?v=fPz6uvIbWZE Imprinting • Rapid and irreversible learning occurring during early stages of an animal’s life – http://videopundits.blogspot.com/2008/01/shaun -sheep-whos-mummy.html Activity • biochallenge on page 368 • quick check questions 5-8 pg 362 • chapter review qu 2-7 pg 369-372 Reflection and homework • What did you learn about learned behaviours today? • Homework: Complete unfinished questions Adaptations for Survival 11: Behavioural EL: To learn about plant behaviour Plant tropisms • A plant growth response to an external stimulus – Light = phototropism – Gravity = geotropism – Thigmotropism = touch http://www.youtube.com/watch?v=1ZuZ_1cQnv4&feat ure=related • Growth towards the stimulus is a positive tropism • Growth away from the stimulus is a negative tropism • Responses rely upon chemical (endocrine) signals in plant cells What type of tropism is shown in these pictures? Plant communication Plant cells will send signals to one another to tell them: 1. When trees to drop their leaves. 2. When to start new growth. 3. When to cause fruit to ripen. 4. When to cause flowers to bloom. 5. When to cause seeds to sprout. Tree Budding Fruit Ripening Cactus Blooming Leaf Drop Sprouting Corn Seeds Plant hormones Hormoneproducing cells • Plant cells produce hormones that travel throughout the plant causing target cells to respond. • In plants, hormones control: 1. Plant growth & development 2. Plant responses to environment Movement of hormone Target cells Plant hormones What causes plants to grow toward light? Phototropism experiments with coleoptiles Auxin • • • • Involved in photo-and gravitropism Stimulates cell elongation Made in the shoot apex Travels down the stem Auxin promotes root growth Other Effects of Auxin • Apical dominance • Prevents leaf abscission (ie leaf shedding) • Enhances fruit growth Auxin • http://www.youtube.com/watch?v=zctM_TW g5Ik Photoperiodism • Photoperiodism is a biological response to a change in relative length of daylight and darkness as it changes throughout the year. • Phytochrome, and other chemicals not yet identified, probably influence flowering and other growth processes. • "Long-day plants" flower in the spring as daylength becomes longer (e.g. spinach). • "Short-day plants" flower in late summer or early autumn when daylength becomes shorter (e.g. broad beans). • "Day-neutral plants" flower when they are mature. Reflection and homework • What did you learn about plant behaviours today? • Homework: – quick check questions 9-13 pg 367 – Chapter review questions 8-10 pg 372 Adaptations for Survival 12: Reproductive EL: To explore reproductive strategies in animals and plants Type of reproduction ASEXUAL SEXUAL Gender system Male and Female Hermaphrodite Parthenogenesis Mode of fertilisation Internal External Mating systems Monogamy Polygamy (polygyny and polyandry) And promiscuity Breeding patterns • Some animals have a set breeding/spawning/ mating season – ensures eggs and sperm available at same time and that environmental conditions are favourable • Can be influenced by internal (i.e. hormones) and external factors (i.e. temperature, day length) Breeding patterns: Mammals • Female mammals produce eggs during oestrus cycle – length varies depending on species: – 28 days in humans (more commonly called menstrual cycle) – 4-6 days on rats and mice – one per year in wolves, foxes and bears • Unlike humans, most mammalian females will only accept mating during oestrus, when eggs are released into the reproductive tract Signs of oestrus Number of offspring • Quick and many: r-selection – Reach sexual maturity early – Produce large numbers of offspring and/or breed more frequently (i.e. high fecundity) – High mortality rates of offspring – E.g. common octopus: 100,000-400,000 eggs! Number of offspring • Slower and fewer: K-selection – Reach sexual maturity slowly and breed later – Produce fewer and larger offspring (i.e. low fecundity) – Extensive parental care, lowering mortality rate – E.g. humpback whales Modes of offspring production • Oviparity: Embryo/s develops externally in eggs released by mother with nutrients from egg yolk. • Viviparity: embryo/s develop within mother’s body and are born live. – Egg yolk viviparity – e.g. grey nurse sharks – Placental viviparity – e.g. placental mammals – Marsupials – strange case! Born to breed: The Antechinus http://www.youtube.com/watch?v=zv7b-KPg9hY Flower structure Flower structure How do plants reproduce? • Plants are sedentary, so need to transport their reproductive cells (pollen) to the eggs of another plant. How? – Blown by wind • what sort of flower would these have? – Carried by an animal vectors (e.g. bees) • what sort of flower would these have? Pollen transfer Wind pollinated Vector pollinated Dispersing offspring • Embryo encased in a seed (sometimes found in a fruit) that can be dispersed through: – wind – Water – In or on animals • Think, pair, share: What would be some adaptations the seeds would need for each of these dispersal methods? Video: Private Life of Plants • http://topdocumentaryfilms.com/the-privatelife-of-plants/ • http://www.documentary-log.com/you-arewatching-the-private-life-of-plants/ Activity: Parental care • Use the information provided and pg 388-390 in your text book to complete the “Parental Care” worksheet • Complete biochallenge (pg 401) with a partner Reflection and homework • What did you learn about reproductive strategies in animals and plants today? • Homework: – quick check questions 1-25 – Chapter review questions 2-13 pg 402-404 Adaptations for Survival 17 EL: To apply our knowledge of adaptations to Australian Fur Seals Activity • Visit http://www.sealeducation.org.au/pinp_index. html and other websites on different species of seals • In pairs, Use the information to complete the following table. You will need to share one adaptation at the end of the lesson Adaptation Type of adaptation (e.g. structural) Increases survival by Variation in other seal species Other information Reflection and homework • How did looking in-depth at the Australian fur seal help you to further understand adaptations for survival? • Homework: Study for adaptations test by reviewing notes, completing concept maps and finishing any unfinished chapter questions Adaptations for Survival 18 EL: To test our understanding of adaptations for survival Reflection • How well do you think you did on your test today? How could you improve your test performance next time? Adaptations for Survival EL: To use our knowledge about habitats and adaptations for survival to create a documentary - By the end of this lesson, you will have decided on your species of investigations and written a rough timeline and plan Reflection • Do you think your timeline and plan will allow you to complete the assignment in time and to a high quality? What letter grade are you aiming for on this piece of work? N.B. Please submit this reflection to me.
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