Which of the following is an example of variation in a population?

The ability to run fast in all animals

The fact that all trees grow tall

What is an acquired characteristic?

A trait developed during an organism's lifetime

A trait that affects one's genetic code

A trait that has always existed

A trait passed from parents to offspring

What is the primary role of adaptations in a species?

To increase the chances of survival and reproduction

To change the species into a completely different one

To ensure all members are identical

Which of the following is NOT an example of variation in a species?

All members being exactly the same

Which of the following is an example of an inherited characteristic?

Knowledge acquired from education

Muscle strength developed from exercise

Evolution (adaptation and Inheritance) worksheet (it should be covered in the British curriculum) Adaptation, adaptive traits, habitat, ecosystem Inheritance, inherited characteristics or acquired characteristics, variation,

EVOLUTION AND BIODIVERSITY: ORIGINS, NICHES AND ADAPTATION

LESSON 3 Characteristics of Living Things Learning Objectives • Describe each characteristic of life • Relate each characteristic of life with how first forms of life evolved What sets living things apart from nonliving things? Organisms are equipped with different characteristics that allow them to grow, adapt, survive, and perpetuate. These include the ability to metabolize, respond to stimuli, interact, and reproduce, among others What are the characteristics of life? Try to look at your surroundings and identify the living things that you see. You have probably identified a lot. Many scientists believe that there are more than 10 million kinds of living things that exist on Earth today. But the question is, how can something be considered living? There are certain characteristics that all living things exhibit: the characteristics of life. Living things are made up of cells. They metabolize, grow and develop, respond to stimulus, adapt to their environment, and reproduce. Living Things Are Made up of Cells All living things are made up of cells. Cells are the basic building blocks of all living things. Each cell contains materials that carry out basic life processes such as respiration. In the 1600s, an argument against the theory of spontaneous generation was made. Italian physician and biologist Francesco Redi disproved the theory that all living things come from nonliving things. Cells have different properties and characteristics. The cell theory describes the properties of all cells. There are three tenets of the cell theory: 1. The cell is the basic unit of life. 2. All living things are composed of one or more cells. 3. All cells arise from preexisting cells. The discovery of the cell is largely attributed to Robert Hooke. Upon examining a piece of cork using a microscope that he built, Hooke observed tiny compartments that he called "cells" (from the Latin word cella, meaning "little room"). Matthias Schleiden suggested that all structural parts of plants are made up of cells. In 1839, Theodore Schwann stated that along with plants, all animals were composed of cells. From these conclusions about plants and animals, advancement on the study of animal parts and functions began. In 1855, Rudolf Virchow included the idea that all cells came from preexisting cells. Some living things are made up of only single cells. Single-celled or unicellular organisms include bacteria, some protists, and some fungi. Even though composed of single cells, these organisms carry out all the functions necessary for life. Most living things such as animals and plants, are multicellular organisms. They are composed of many cells, which are grouped together and perform specific tasks in the body. In different organisms, cells also vary in sizes, shapes, parts, and functions. There are two kinds of organisms according to their cell structure, the prokaryotes and eukaryotes (figure 5-3). Prokaryotes are single-celled organisms that lack a membrane-bound nucleus, mitochondria, and all other organelles. Its name comes from the Greek words pro, which means "before," and karyon, which means "nut or kernel." Eukaryotes are organisms with cells that contain membrane-bound nucleus and other membrane-bound organelles. The nucleus of a eukaryotic cell contains the genetic material (DNA), enclosed by a nuclear envelope. Other membrane-bound organelles are mitochondria, Golgi apparatus, and chloroplast found in photosynthetic organisms such as algae and plants. There are also unicellular eukaryotes known as protozoa. All other eukaryotes are multicellular organisms, such as plants, animals, and fungi. Living Things Metabolize Essential chemical reactions in life can be best described as building up (anabolism) and breaking down (catabolism) processes. In anabolism, the substances needed by organisms to grow, store energy, and repair tissues are synthesized. In contrast in catabolism, some complex substances are broken down, releasing the energy stored in their molecules. This happens in food digestion. This chemical building up and breaking down processes are collectively called metabolism. Metabolism, from the Greek word metabole meaning "change," is the sum total of all the life-sustaining chemical reactions in living things. It allows living things to grow, maintain their structures and functions, and respond to stimuli. Living Things Grow and Develop Growth and development are not new concepts to many. In all living things, growth involves the increase in one's size or height. However, growth is not just an increase in physical structure. It also involves complex changes in an organism. Growth and development occur rapidly from younger stages of life to maturity. In humans, animals, and plants, distinct changes brought by growth and development can be dearly identified. Microorganisms such as bacteria also undergo growth and development until they reach their maximum size and maturity. A life span is the average length of time a aving thing can live. Living things have different life spans. Humans have average life spectancy of 60 to 70 years, while some plants, such as the narra trees, can live for more than 100. Living Things Respond to Stimuli All living things respond to stimuli the environment. This responsiveness Increases survivability. Stimulus (plural: uli) is any signal or change in he environment of an organism that produces a response or reaction from that organism. Responses to stimuli depend on an organism's need. Responding to stimuli also maintains homeostasis in living things. Homeostasis is the internal balance of a body system. This balance is needed for the proper function and regulation of the living thing's body. For example, when a person is in a warmer environment, the body sweats, keeping the body maintain a temperature suited for the normal function of the body. Living Things Interact No living thing can live alone. Interaction among organisms is simultaneously happening on Earth. From the smallest microorganisms to the biggest organism, and from the North Pole to the South Pole of Earth, all are connected in one living system. An ecosystem is formed when a community of organisms interacts with another community and with their environment. Many processes and interactions, such as in a feeding relationship, life cycle, and the exchange of gases between plants and animals, occur in the ecosystem. These are some of the important processes needed to maintain life on Earth. Living Things Reproduce The ability of living things to produce offspring of their kind is called reproduction. Reproduction is not an individual organism's need, rather, it is for the species' perpetuation. In some cases, animals become extinct because of their inability to reproduce their kind. Higher forms of plants and animals reproduce through sexual reproduction. Sexual reproduction involves the union of sex cells or gametes-the egg cell from a female organism and the sperm cell from a male organism. This union gives rise to a new individual with characteristics or traits from both parents. Other simple organisms, such as bacteria and plants, can reproduce asexually. These organisms give rise to a new individual from their body. A bacterial cell divided in two through asexual reproduction gives rise to new bacteria, as shown in figure 5-5. A yeast can form buds that later on become separate individual. Plants grow new plants using their stem, leaf, and roots. Both sexual and asexual reproductions have important functions. In both cases, the genetic material (DNA) is passed on from one generation to the next, ensuring the survival of the species on Earth. 1. Bacteria copy their DNA by starting at any point on the circular chromosomes. 2. The two copies of DNA attach to the inside wall of the bacterial cell. 3. The cell starts to divide, forming a new membrane and cell wall. 4. The bacterial cell splits into two separate cells, each with their own DNA. Living Things Adapt and Evolve All living things can adapt to their environment. This adaptation is necessary for rvival. Adaptation depends on the need of an individual. A polar bear, for example, would not be able to survive in an extremely cold environment without its capacity adapt. Adaptation is any response or reaction toward a stimulus that helps in the survival of an organism. A seed-eating bird will eventually eat a worm when there are seeds to be found. This change in food choice is therefore its adapting mechanism. Prolonged adaptation to certain environments may lead to the gradual evolution of the succeeding generations. Evolution is the gradual change in organisms over a long period in response to changing environment. Living Things Are Organized Life on Earth exhibits organization. The atom is the smallest unit of matter, lowed by molecules, which are combinations of atoms. When these molecules are grouped together, they form a cell. The cell is the basic unit of life. In multicellular organisms, such as plants and animals, cells are grouped as tissues to perform specific Functions. Different tissues can be grouped further and form organs. Organs in animals include the heart, brain, and lungs, among others. The organs form organ systems that makes the function of the body more complex and efficient. Organ systems form the whole organism. All living things exhibit organization, whether they are unicellular or multicellular organisms..

Evolution and Adaptations Unit Quiz

As long as the birth rate of a population exceeds the death rate, the population size will continue to increase. At a steady, positive per capita growth rate, the population will add a larger number of indi- viduals with each generation. So, a population can increase rapidly with even a small growth rate. A pattern of increase in number due to a steady growth rate is called exponential growth. The observa- tion that populations can grow in this pattern is called the exponential (EKS-poh-NEN-shuhl) model of population growth. One way to understand the exponential model is to study a graph of population size over time. A graph of exponential growth makes the characteristic J-shaped curve shown in Figure 19-6. With expo- nential growth, population size grows slowly when it is small, but growth speeds up as individuals join the population. The exponen- tial model leads us to predict that the population size will increase indefinitely and by a greater number with each time period. Applying the Exponential Model A scientific model is useful if it helps to predict or explain pat- terns that can be observed in reality. Indeed, the exponential model matches observed patterns of growth of real populations, but only under certain conditions and for limited periods of time. For example, a population of microorganisms can grow exponen- tially if provided with an abundance of food and space and if waste is removed. Figure 19-7 shows the growth of bacteria in a laboratory. However, the exponential model does not apply to most popu- lations. In natural environments, populations cannot grow indefi- nitely because the resources they depend on become scarce and harmful wastes accumulate. Any factor, such as space, that restrains the growth of a population is called a limiting factor. All populations are ultimately limited by their environment.SPECIES INTERACTIONS Just as populations contain interacting members of a single species, communities contain interacting populations of many species. Many species have specific types of interactions with other species. This chapter introduces the five major types of interactions among species: predation, competition, parasitism, mutualism, and commensalism. These categories are based on whether each species causes any benefit or harm to the other species in a given relationship. PREDATION In predation (pree-DAY-shuhn), an individual of one species, called the predator, eats all or part of an individual of another species, called the prey. Predation is a powerful force in a community. The relationship between predator and prey influences the size of each population and affects where and how each species lives. Examples of predators include carnivores—predators that eat ani- mals—and herbivores—predators that eat plants. Many types of organisms can act as predators or prey. All heterotrophs are either predators or parasites or both. Predator Adaptations Natural selection favors the evolution of predator adaptations for finding, capturing, and consuming prey. For example, rattlesnakes have an acute sense of smell and have heat-sensitive pits located below each nostril. These pits enable a rattlesnake to detect warm- bodied prey, even in the dark. Many snakes use venom to disable or kill their prey. A venomous rat- tlesnake is shown in Figure 20-1. Other predator adaptations include the sticky webs of spiders, the flesh-cutting teeth of wolves and coyotes, the speed of cheetahs, and the striped pat- tern of a tiger’s coat, which provides camouflage in a grassland habitat. Many herbivores have mouthparts suited to cutting and chewing tough vegetation. A predator’s survival depends on its ability to capture food, but a prey’s survival depends on its ability to avoid being captured. Therefore, natural selection also favors adaptations in prey that allow the prey to escape, avoid, or otherwise ward off

Students will demonstrate a comprehensive understanding of natural selection, evolution, and the evidence supporting these concepts—including DNA, analogous and homologous structures, vestigial structures, embryology, and fossil records—by completing a 25-question multiple-choice test that assesses their knowledge of species, adaptations, overproduction, variation, competition, and the contributions of Charles Darwin.

Make a multiple choice quiz for my year 8 science students based on the science in this transcript from a video: 3°C 0:04 It can be the difference between snow and sleet 0:08 Wearing a jacket or not 0:11 In your day-to-day life, it may not seem significant 0:15 But 3°C of global warming would be catastrophic 0:20 Heatwaves, droughts, extreme precipitation, even fire 0:25 3°C of warming is really disastrous 0:28 The scary thing is, the world is well on its way there 0:32 Since the industrial revolution, the Earth has warmed between 1.1°C and 1.3°C 0:40 This is a problem that babies you pass in the street will have to live with 0:46 Children born today... 0:47 ...are up to seven times more likely to face extreme weather than their grandparents 0:52 If global temperatures do rise by 3°C... 0:55 ...what would their world look like? Climate change is already having devastating effects 1:03 Rising sea levels 1:05 Desertification 1:07 Hollywood has always enjoyed imagining the end of the world 1:11 While blockbusters like this are clearly fiction... 1:14 ...this film will show the scenario we all face... 1:17 ...unless more drastic measures are taken to stop burning fossil fuels 1:30 In some parts of the world the effects of inaction are already clear 1:35 The slums of Bangladesh’s capital are filling up with climate migrants 1:41 Minara comes from Bhola District, an area in southern Bangladesh 1:46 There, like many other parts of the country... 1:49 ...rivers swollen by heavier rain and melting Himalayan glaciers... 1:53 ...are washing away people’s homes 1:56 Many, like her, have lost everything 2:00 Our home in Bhola had endless amounts of land 2:03 There was lots of space for farming, we had a spacious house 2:08 There were different types of fruits, vegetation and trees growing at home 2:12 We used to eat the fruit from our own trees 2:18 I can’t eat them now because they don't exist anymore 2:21 Since the river flooded for the third time, I had to flee to Dhaka 2:26 Life was much better back home 2:29 It was unbearable to live through, truly intolerable 2:33 We didn’t have the time to save anything at all 2:38 1.1°C to 1.3°C of global warming has already transformed Minara’s life 2:45 It’s one of the reasons why so many migrants like her... 2:47 ...are moving to the city each year... 2:50 ...nearly 400,000 according to the last estimate 2:53 And climate models show there could be much worse to come How climate modelling works 3:02 Climate scientist Joeri Rogelj... 3:04 ...has spent the last ten years modelling future climate scenarios... 3:08 ...for the United Nations 3:10 The models we use to carry out this exercise... 3:13 ...really represent the state of the art... 3:15 ...of our current knowledge of climate change and where we are heading 3:19 Joeri’s projections use data collected by hundreds of scientists around the world 3:26 Here this is the 3°C level... 3:28 ...and so there is at least a one-in-four chance that under current policies... 3:32 ...we would hit 3°C by the end of the century 3:36 This is just one of the scenarios Joeri looks at 3:40 Another one imagines that all policy promises are kept 3:44 The most optimistic assumes that all promises have been kept... 3:47 ...and net-zero targets are met 3:50 Where our best estimate ends up around 2°C at the end of the century... 3:54 ...there is still a one-in-20 chance that we end up with 3°C instead 3:59 One would not be entering a plane if there is a one-in-20 chance... 4:03 ...that the plane will crash Nowhere is safe from global warming 4:07 A rise of 3°C would affect everyone 4:10 Even wealthy cities in rich countries wouldn’t be immune to the consequences 4:15 European capitals like Paris and Berlin... 4:18 ...would bake under more extreme heatwaves 4:22 Frequent storm-surges in New York could turn parts of the city desolate 4:27 In many ways, cities magnify, intensify climate events 4:33 Cities are hotter than the places around them... 4:36 ...they tend to be more vulnerable to flooding 4:39 And you can get a really bad event in a city in a way that you can’t in the countryside 4:46 And because of their denser populations... 4:49 ...disasters in a city affect far more people 4:52 Some cities might be badly prepared for the changes coming 4:56 But they have the means to adapt 4:59 Cities tend to be wealthier than surrounding places 5:03 They have a lot of amenities 5:05 A city that has taken seriously the risks of a 3°C world... 5:08 …wouldn’t necessarily be a worse place to be in a 3°C world 5:12 But a city that hasn’t prepared for these sort of eventualities... 5:16 ...that might be a really nasty place The impact of prolonged droughts 5:20 So far, many developed cities have got off lightly... 5:24 ...but some rural parts of the world are suffering disproportionately 5:29 Smallholders—small-scale farmers—are particularly vulnerable to climate change 5:35 And there are over 600 million around the world 5:38 Smallholders with farms under two hectares... 5:40 ...produce around a third of the global food supply 5:46 Central America’s “Dry Corridor”... 5:48 ...supports a mix of smallholdings and medium-sized farms 5:53 Sandwiched between the Pacific Ocean and the Caribbean Sea... 5:56 ...the area is prone to droughts 6:08 Israel Ramírez Rivera is a smallholder in Guatemala 6:12 Here, climate change is making the dry seasons longer, and more severe 6:18 This is the biggest ear of maize that this plot could deliver 6:23 He depends on his crops of corn and beans 6:26 But they’re getting harder to grow 6:30 The surrounding mountains... 6:32 ...used to provide us with native food... 6:38 ...and now that isn’t an option anymore... 6:41 ...due to climate change and its effects 6:46 Nearly two-thirds of the smallholders in the Dry Corridor now live in poverty 6:52 The impact of all of this for us... 6:59 ...malnutrition among children 7:03 We’ve lost a few 7:07 For my crops especially, the midsummer heat is harder than before 7:16 The plant dries up and can’t provide us... 7:19 ...with the necessary food provision 7:24 Severe droughts in Central America... 7:26 ...are now four times more likely than they were last century 7:30 Many families from here have gone to the States 7:37 The economic despair and debts... 7:44 ...have pushed many people from this community to do this journey 7:53 Migration from Guatemala to the United States has quadrupled since 1990 7:59 Not all of this has been due to climate change 8:02 But longer droughts would force even more to move 8:05 In a 3°C world, annual rainfall in this region... 8:09 ...could drop by up to 14% 8:12 At 3°C, over a quarter of the world’s population... 8:16 ...could endure extreme droughts for at least a month of the year 8:19 Northern Africa could see droughts that last for years at a time Rising sea levels, storm surges and flooding 8:24 But for some, too much water will be the problem 8:29 10% of the world’s population lives on a coastline... 8:32 ...that’s less than 10 metres above sea level 8:35 For these coastal inhabitants, a 3°C world would spell disaster 8:40 By 2100, global sea levels could have climbed by half a metre from 2005 levels 8:46 Low-lying cities like Lagos would be especially vulnerable... 8:49 ...with up to up to a third of the population displaced 8:54 And in Fiji, rising waters are already upending lives 9:04 You can see the graveyard there, it’s all under water now... 9:08 ...due to this rising sea level and climate change 9:15 The village of Togoru in Fiji is being swallowed by the sea 9:19 Barney Dunn, the village headman, has seen over half the village disappear 9:24 Relatives’ houses have been abandoned, and family graves are now under water 9:29 We have been asked by the government to relocate... 9:32 ...but no one wants to relocate... 9:34 ...because we have our great-great-grandparents down there in the sea 9:39 This is the place we’ve been brought up in 9:41 ...it’s not easy to leave 9:44 Past attempts to build a seawall haven’t worked 9:48 But Barney sees building a new one as the village’s only hope 9:52 If they do that, maybe we can save whatever is left 9:56 But if we don’t have the seawall, then it will be keep eroding and time will come... 10:01 ...maybe in ten,15 years, Togoru will be all eroded 10:05 Rising seas also mean storms cause more floods 10:11 And many more countries could suffer 10:14 The Philippines and Myanmar are just two countries... 10:17 ...that will also see an increase in storm surges in a 3°C world 10:21 To escape, many will move… 10:24 …often, to urban areas Extreme heat and wet-bulb temperatures 10:27 Half the world’s population already lives in cities... 10:31 ...almost a third in slums 10:36 For them, a 3°C world could be deadly 10:40 Minara has moved to Dhaka to escape the impact of climate change 10:44 But life could get even worse for her 10:47 I’m struggling a lot nowadays 10:49 The heat during the day is unbearable 10:52 Even late at night it doesn’t cool down 10:57 The heat is getting more intense every day 10:59 I mean, it’s going to get much worse 11:03 I can barely survive it now, how will I live through it in the future? 11:08 Dhaka is getting hotter 11:11 In the last 20 years the average daytime temperature... 11:13 ...has crept up by nearly half a degree 11:17 Days that approach 40°C are now being reported 11:20 And high so-called wet-bulb temperatures are on the rise 11:26 A wet-bulb temperature is a measure of heat and humidity 11:30 Humans cool themselves by sweating… 11:32 But in these conditions, when relative humidity is near 100%... 11:36 ...sweat doesn’t evaporate well 11:38 So people can’t cool down… 11:41 ...even if given unlimited shade and water 11:45 At a high wet-bulb temperature, the body can’t lose heat... 11:49 ...and so it gets hotter and hotter... 11:51 ...and the body is designed to work at a given temperature 11:53 And if it gets too hot inside, you will die 11:58 The human limit for wet-bulb temperatures is 35°C... 12:02 ...around skin temperature 12:04 Dhaka will have a much higher chance... 12:05 ...of reaching dangerous wet-bulb temperatures... 12:07 ...if global warming reaches 3°C 12:12 You can’t really adapt to that 12:14 You have to get out. If the temperature is so high that you can’t work... 12:20 ...can’t do hard manual labour outside for significant parts of the year... 12:25 ...then many places will become functionally no longer part of the economy 12:33 Jacobabad in Pakistan, and Ras al Khaimah, in the United Arab Emirates... 12:37 ...have already recorded deadly wet-bulb temperatures 12:40 More of the tropics and the Persian Gulf... 12:43 ...as well as parts of Mexico and the south-eastern United States... 12:47 ...could all get to this threshold by the end of the century 12:50 Climate modelling might show us the weather Increased migration and conflict 12:52 But it doesn’t show us its other effects on society 12:56 Established migration patterns could change 12:59 Climate disasters may exacerbate reasons people cross borders 13:03 Within countries, more people will move to cities 13:07 In a 3°C world, tens of millions of people a year... 13:10 ...could be displaced by disasters made worse by climate change 13:15 When people are displaced by climate... 13:18 …they may well go to cities... 13:19 ...because cities are the places that attract people from the countryside already 13:25 A lot of people who can get to the developed world... 13:28 ...not least because the developed world tends to be less hot, will give that a go 13:35 As migration around the world increases... 13:38 ...there could be more competition for fewer resources 13:42 Water—already a highly contested resource—will be a focal point 13:47 Turkey’s new Ilisu dam has reduced the flow of water into Iraq 13:53 China lays claim to rivers vital to India and Pakistan 13:57 The prospect of a water-conflict makes people very uneasy 14:03 How national tensions would exacerbate those sorts of reactions... 14:08 ...in a 3°C world... 14:09 ...is the sort of thing that no one should really want to find out 14:14 I think you’d have to be incredibly sanguine... 14:16 ...not to think that the sort of climate extremes that we talk about... 14:19 ...in a 3°C world wouldn’t lead some places... 14:22 ...to the brink of societal collapse 14:25 Those lucky enough to escape unrest... Adaptation and mitigation are crucial 14:28 ...would still have to adapt to a radically different world 14:32 People can adapt to climate change in all sorts of ways, one of the most obvious ones... 14:37 ...is air conditioning 14:39 But other ways to adapt at a local or regional level... 14:42 ...I mean, one of the most obvious is diversifying agriculture 14:47 There are physical things you can do, like seawalls 14:52 The fact that people can adapt and that adaptation will reduce suffering... 14:57 ...doesn’t mean that it will eliminate suffering 15:00 Suffering is built into this whole process of heating up the planet 15:06 Adaptation will only get the world so far 15:09 The best way to deal with a 3°C world... 15:12 ...is not to go to a 3°C world 15:14 And that’s why increasing efforts on mitigation are important 15:17 It’s why working towards negative emissions... 15:20 ...that could bring down the temperature after it peaks are important 15:25 Once you get to a 3°C world, you are in real bad global trouble 15:33 The scale of change needed... 15:35 ...and the slow progress of governments so far... 15:38 ...means 3°C of warming is uncomfortably likely unless more is done 15:44 Despite existing pledges, greenhouse-gas emissions... 15:48 ...are still set to rise by 16% from 2010 levels by 2030 15:54 The need to act has never been clearer 15:57 There’s still time to reduce emissions, so that a 3°C world remains fiction... 16:02 ...rather than becoming fact

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