9A Biological Diversity - PDF

9A Aspden 2021/22 9A Biological Diversity 1 What is biological diversity? Recall: ❖ A species is a group of organisms that look similar and can reproduce. ❖ A population is a number of o...

9A Aspden 2021/22 9A Biological Diversity 1 What is biological diversity? Recall: ❖ A species is a group of organisms that look similar and can reproduce. ❖ A population is a number of organisms of the same species living in a particular area. ❖ A community is the interaction of many species that depend on one another in an environment. pie i ptg Mtg jgggg.g.gg jgg SPECIES By B POPULATION ❖ Biodiversity refers to variation in nature. COMMUNITY ↳ Species diversity refers to the variety of different species in an ecosystem. ↳ Habitat diversity refers to the variety of habitats available for different species to survive in. ↳ Ecosystem diversity refers to the variety of life-supporting environments on Earth. É tt Diversity ❖ As a general rule, biodiversity is greater towards the equator and lower towards the poles. Ecosystems Ijj Iggy near the equator are warmer and less harsh to live in. ↳ (The equator passes through the Amazon rainforest, not the north pole.) ❖ As a general rule, there will be a greater diversity of Yismotias 411 smaller species (flowers, insects) in an ecosystem when compared with the diversity of larger species (birds, mammals). 1 of 16 9A Aspden 2021/22 ❖ The biodiversity of a specific area can be described using a biodiversity index (BI). 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑖𝑛 𝑎𝑛 𝑎𝑟𝑒𝑎 𝑏𝑖𝑜𝑑𝑖𝑣𝑒𝑟𝑠𝑖𝑡𝑦 𝑖𝑛𝑑𝑒𝑥 (𝐵𝐼) = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑜𝑟𝑔𝑎𝑛𝑖𝑠𝑚𝑠 𝑖𝑛 𝑎𝑛 𝑎𝑟𝑒𝑎 Forest iffffff sit it ❖ There are two types of variation found in living things: variation within species and variation between species. written ttʰ YEFIEEno.fi 19 a species species ❖ Within a species, variation can either be discrete (described by groups/words) or continuous (described with numbers/on a scale). father Pithoragarh height EE.sho.ge Kalaw CONTINUOUS DISCRETE Thoughtfulness attype IQ weight ❖ Species with more variation are more likely to survive drastic changes to their environment (e.g. disease, flooding, etc.) compared with species that have little variation. ↳ If all of the organisms in a species were identical, then they would all be susceptible to the same potential harms and dangers. In nature, there is strength in differences. 2 of 16 9A Aspden 2021/22 2 What is an ecological niche? ❖ A niche is the role a species plays in its environment. ❖ The niche of a species includes: ↳ what it eats and/or what it gets eaten by ↳ its other relationships or interactions with different species planktonand ↳ its habitat relies on filters makesfoodfor water omnivores flowersfor krilloutof HONEY nectar HUMBACK good creates BEE foundnear WHALE coastlines nestsin provides openwater pollinates treesand flowers habitatto logs near barnacles ❖ An adaptation is a structure or behaviour that helps an organism survive and reproduce. ❖ The niche of a species is directly related to its adaptations. sharpteeth to'Fhotosynthesis caitiffs EÉE feathers Flatteeth yyEALTH gyppy smoothfeathers SPEED I.at shPEdsFEIB1oYIIEnE pawn's Nectar gr 8147 SHORT TOUGH beak LONG POINTY beak i d stronger fitsintosmaller 3 of 16 9A Aspden 2021/22 ❖ A species can be classified as specialist or generalist based on its niche: ↳ specialists have “narrow” niches: they survive on a very specific food source or in a very specific habitat. ↳ generalists have “broad” niches: they survive on a wide variety of food sources and in a wide variety of habitats. ❖ Generalist species are less affected by changes to their environment than specialist species. ERAtSTs Population ea.nu GOOD Environmentadditions ❖ When the niches of two or more species overlap, it results in interspecies competition. ❖ When two closely related species divide the resources/habitat in their environment and do not compete with each other, this is called resource partitioning. I.EEE.s NTEEIE.fi on resource PARTITIONING p swansen dfiiaafdhdooqage.ie www.netflix Eddison dafdfqgghffffdd iiffargftaaa breasted Black throated io.ir Bay SPELEE ÉÉÉ 4 of 16 9A Aspden 2021/22 ❖ The species in an ecosystem coevolved together and depend on one another to survive. ↳ Examples of this interdependence include food webs, predator-prey relationships, and symbiotic relationships. ❖ A symbiosis is a close relationship between two different species where at least one of the species depends on the other for survival. SYMBIOSIS SPECIES 1 SPECIES EXAMPLES mutualism faithffoilmann intimas BBBnests thanks COMMENSALISM jfii.it jf mosquitoes tick PARASITISM of me mpeps ❖ When a predator species relies primarily on one prey species for its food, their populations can cycle up and down together in a feedback loop. PREY peaks popgolation www AE Ei nifii peep peaks Time ❖ In a food web, where there are many interconnected food relationships between different species, changes to the population of one species can cause changes to the populations of many other species. 5 of 16 9A Aspden 2021/22 3 What is DNA, and what is genetics? ❖ Genetics is the study of heredity. ❖ Heredity (or biological inheritance) is the passing on of traits from parents to their offspring through DNA/genes. ↳ Offspring ( or “children”) are the copies an organism makes of itself through reproduction. ❖ Traits are the characteristics of an organism, such as hair colour, blood type, or susceptibility to certain behaviours or illnesses. ❖ Traits can either be heritable or acquired: ↳ Heritable traits are passed from parents to their offspring through DNA. ↳ Acquired traits are learned or caused by the environment in which an organism lives. instincts Fazenda Emma Fgears MAME strength A hairdos skillsand III she bloody memories ❖ DNA (deoxyribonucleic acid) is the genetic material found in the nucleus of the cell. It contains the set of instructions for creating a particular organism, and it also directs the activities of the cell. a t ↳ DNA is a very long double helix (“twisted ladder”) molecule made up of two strands 9 stuck together. t a ❖ Each strand of DNA is made of repeating units É called nucleotides. ↳ There are four nucleotides: adenine (A), thymine (T), cytosine (C), and guanine (G). so an c ❖ Pairs of nucleotides stuck together are called I base pairs. ↳ A and T are always paired together c ↳ C and G are always paired together BASEPAIR ❖ DNA encodes information as sequences of base pairs, which can be read and acted on by special 1 NUCLEOTIDE SUGAR proteins in the cell. PHOSPHATE BASE 6 of 16 9A Aspden 2021/22 ❖ A gene is a basic unit of heredity: it is a specific section of DNA that contains the instructions for making a specific protein or directing a specific activity in the cell. In essence, genes encode traits. ↳ A genome is all the genes of a particular species. The human genome contains ~30,000 genes. ❖ Chromosomes are long strands of DNA containing many genes. CHROMOSOME DNA GENE Ego zjg hair colour gene Mennenga ❖ Human DNA is organized into 23 pairs of chromosomes (46 in total). ↳ One chromosome from each pair comes from your biological mother, and the other comes from your biological father. ↳ Different species have different numbers of chromosomes. ❖ One pair of chromosomes is called the sex chromosomes. The genes on these chromosomes encode the sex characteristics of a species (e.g. testosterone/estrogen levels, genitals, etc.) ↳ Females have two X chromosomes (XX). ↳ Males have one X and one Y chromosome (XY). XX FEMALE XY MALE 7 of 16 9A Aspden 2021/22 4 How do living things grow and reproduce? ❖ There are two types of reproduction: asexual and sexual. ↳ Asexual reproduction requires only one parent, is generally fast and efficient, and produces offspring that are genetically identical to the parent (“clones”). ↳ Sexual reproduction requires two parents, is generally slow, and results in offspring that are genetically different from both parents. IF t I aÉl ASEXUAL y SEXUAL ❖ There are four types of asexual reproduction: Binary Fission Vegetative Reproduction i runners yYgjjs gg bacteria only plantsonly Spores Budding 0.8 tafia i bud plants's fungi plants animals i fungi 8 of 16 9A Aspden 2021/22 ❖ Sexual reproduction involves the creation of gametes (sex cells). ↳ The ovum (egg cell) is the female gamete. ↳ The sperm is the male gamete. ❖ Living things are mostly made of somatic cells (body cells), but all species that reproduce sexually also produce gametes. GAMETES ÉÉ Piotr CELLS Ei CELLS M ❖ Cell division is when a parent cell splits to make daughter cells. ↳ DNA replication is when a cell makes a copy of its DNA. It is the first step in any cell division. ❖ There are two types of cell division: ↳ Mitosis refers to cell division used for growth and repair. Mitosis produces two daughter cells, each with the same number of chromosomes as the parent cell. ↳ Meiosis is cell division used for creating gametes. Meiosis produces four daughter cells, each with half the number of chromosomes as the parent cell. BODYSELLS PARENTYELLDNFeplication Mitosis xxxx d Kx it t PARENTCELL GAMETES DNFeptato Meiosis K MEIOSIS 2 it Y 111 till xxx x E is it ❖ Fertilization refers to the process of a sperm combining with an ovum to produce a zygote. ❖ A zygote is the first cell of a new organism. A zygote repeats mitosis to become an embryo. ❖ An embryo refers to an early developing multicellular organism. ❖ In mammals, sperm are produced in the testicle and ova are produced in the ovary. EM if MALE I GAMETE MEIOSIS FERTILIZATION CEIL 0 raw EMBRYO FEMALE 9 of 16 ovum 9A Aspden 2021/22 ❖ In plants, sperm are found in pollen grains and ova are found in ovules. ↳ Sperm and ova are usually made by the same plant, although some plant species also have separate male and female organisms. ❖ Cross-pollination is the spread of pollen from one plant to a different plant. ↳ In flowering plants, pollen is released from the stamen (male part of the flower) and lands on the sticky top of the pistil (female part of the flower). ↳ Conifers (cone-producing trees) produce male and female cones instead of flowers. ❖ A plant can also self-pollinate if a pollen grain lands on one of its own flowers. ↳ Self-pollination results in a genetically identical plant and produces offspring with little variation. fats cross pollination food self pollination f ftp.agg Phrase ff pnomination ifin g affair less variation ❖ Some species can reproduce either asexually or sexually, depending on environmental conditions. ↳ Sexual reproduction is always preferred over asexual reproduction due to the variation it produces. However, harsh environmental conditions or a lack of mating partners can make sexual reproduction difficult. ↳ In nature, it is more useful for an organism to reproduce asexually and produce little to no variation than to not reproduce at all! iiIifiiiEen I if A Qff.it 1K 10 of 16  9A Aspden 2021/22 5 What are patterns of inheritance? ❖ Alleles are variations of the same gene. Different alleles produce slightly different traits. ❖ Dominant alleles/traits are always expressed when they are present in an organism’s DNA. ❖ Recessive alleles/traits are only expressed when an organism’s DNA contains two of them. ❖ A genotype refers to the pair of alleles an organism’s DNA contains. ↳ Dominant alleles/traits are always represented using capital letters. ↳ Recessive alleles/traits are always represented using lowercase letters. ❖ A phenotype refers to the specific trait that is expressed in an organism as a result of its genotype. GENOTYPE allelepair PUREEF p.grfE INKALLELE 8 00360 ORANGE ALLELEargon 2 A REDALEEoffer pHÉÉTypÉ appEEnÉ ❖ If you know the genotype of both parents for a particular trait, you can determine the probability of observing those traits in their offspring using a Punnett square. P P p P OPP P PINKALLELE 83m00 g P P 100 pink 100 pink DOMINANT P Kapitalletter ORANGEALLELE 003000 RECESSIVE P Iwan P p p p P P p p atge iss.io ridge 11 of 16 9A Aspden 2021/22 ❖ If an organism’s DNA contains two dominant alleles, they will sometimes both be expressed. ❖ Incomplete dominance refers to when the phenotypes of two parents blend together to create a new “blended” phenotype in their offspring. ❖ Codominance refers to when both alleles are expressed separately without mixing. INCOMPLETE f dominance blend 9 a CODOMINANCE combo 12 of 16 9A Aspden 2021/22 6 What is natural selection? What is artificial selection? ❖ Evolution is the change in the characteristics of a species over several generations. ↳ Over long periods of time, evolution produces new species. ❖ Evolution is the natural result of three things: ↳ Reproduction ↳ Variation ↳ Natural selection ❖ Mutations are changes to a DNA sequence caused by errors during DNA replication or by environmental causes (eg. UV damage, chemical reactions). ↳ Mutations are a natural, random source of variation. Mutations can give an organism an advantage, be harmful, or can have no effect. MUTATION Wrx Amn ❖ Natural selection refers to the way that nature “chooses” which organisms get to reproduce and pass on their traits to the next generation. ↳ The phrase “survival of the fittest” can be paraphrased as “the organisms that are best adapted to their environment are more likely to survive and reproduce.” ❖ “Selection” most often results from competition over limited resources, especially food and mating partners. ↳ For example, if a bird is born with a mutation to its beak that allows it to produce a strong bite, then it might be able to eat nuts or seeds that members of its species cannot. This will give the bird a greater chance of surviving, reproducing, and passing on its “strong beak” trait to the next generation! ❖ Selection can also result from changes to an environment, such as the spread of a new disease or a sharp change in climate. Reproduction with NATURAL 1 for as VARIATION SELECTION limitedresources 00I 0o 13 of 16 9A Aspden 2021/22 ❖ Artificial selection (or selective breeding) refers to the process by which humans select organisms with desirable traits to reproduce in order to increase the presence of a trait in a population. ❖ Humans have developed many techniques throughout history that allow us to control the reproductive process and the spread of traits within a population: ↳ Artificial pollination/insemination is the controlled fertilization of a female plant or animal with the pollen/sperm from a selected male organism. POLLE t.it ittftffi.in ever ii ↳ In vitro (“in a test tube”) fertilization – often used to assist couples who have difficulty having a child – is when an egg is fertilized with sperm outside the body of a female. The zygote is then implanted back into the uterus of the female to develop. ↳ Artificial cloning is the process of making an identical copy of an organism. In animals, this essentially requires the transfer of DNA from a parent cell into a zygote. df Thefirstmammalian done atlyB mmzg.m.gl 1994003 ↳ Genetic engineering refers to the direct editing of an organism’s DNA, often through the transfer of a gene or specific segment of DNA from one organism to another. A transgenic organism is one that has had the genes of another organism inserted into its DNA. gensplicing iiioriawo.ia.fi i 14 of 16 9A Aspden 2021/22 7 Why should we care about biological diversity? ❖ In many ways, biological diversity can be thought of as a nonrenewable resource. ↳ Biological diversity is beneficial to human survival, but cannot be easily renewed when it is destroyed. After all, a species typically takes thousands or millions of years to evolve! ❖ Extinction is the dying-off of a species from the entire earth. ↳ Extirpation is the dying-off of a species from one particular region. ↳ When a species is endangered, it means that it is at a high risk of extinction. EXTINCTION Éf Extirpation w fffFfIf ffyff.fi digged ❖ Over the last 600 million years, there have been five major extinction events (major declines in Earth's biodiversity.) These have been caused by disasters (e.g. dinosaur-killing asteroids, supervolcano eruptions) or by changes to Earth’s living conditions (e.g. atmosphere, temperature). ❖ Historically, the rate of extinction has typically been about 1 extinction per year. ↳ Today, species are going extinct at a rate of approximately 3 extinctions per hour!!! In other words, we are currently in the midst of Earth's sixth major extinction event, and this event is being caused by humans! ❖ The leading cause of extinction is habitat loss. ↳ Humans are destroying habitats all around the world in order to make more room for farms, communities, and infrastructure (roads and pipelines). ❖ The destruction of habitats, and therefore habitat diversity, is directly related to the extinction of species. Preserving habitats goes hand-in-hand with preserving biological diversity. ❖ Two other common causes of extinction are: ↳ Invasive/introduced species, which can outcompete the native species in an ecosystem. ↳ Over-hunting/over-fishing 2 1 i a aifff.FI IEI iiiiiii ae.ii.it.in Loss 15 of 16 on 9A Aspden 2021/22 ❖ Conservation refers to the protection of biodiversity. ❖ Zoos are more than just places to display plants and animals. Many zoos play dual roles as both educational and research institutions. ↳ Many zoos are part of a global network of institutions that is trying to protect and preserve endangered animals, and protect biological diversity as a whole. ↳ Zoos are a form of ex-situ conservation, where conservation occurs outside of an organism's natural habitat. ❖ In-situ conservation focuses on preserving and protecting species within their natural habitats. ↳ Protected areas like national and provincial parks, nature preserves, and nature refuges are common examples of in-situ conservation. Fiigiiiiii.fi EISITU ❖ Seed banks are places where seeds from all around the world are stored in carefully controlled conditions so that they can remain viable long into the future. ↳ Seed banks run by governments and universities play an important role in preserving and studying plant diversity. ↳ In the future, seeds from these banks may be useful in replenishing lost diversity in the wild. ❖ Global treaties are agreements between nations. Several agreements have been made between Canada and other countries in order to protect biodiversity: ↳ The 1975 Convention on International Trade of Endangered Species (CITES) is aimed at preventing endangered plants, animals, or parts of these organisms from being imported or exported from their native countries. This law makes it illegal to buy or sell endangered animals such as rare birds, reptiles, or amphibians. It also makes it illegal to buy or sell animal parts such as rhino horns or elephant tusks, which are used to make jewellery, sculptures, or folk remedies. ↳ 180 countries have also signed the 1992 Convention on Biodiversity and have agreed to set up protected areas for threatened and endangered species. ❖ National and global organizations such as the Canadian Wildlife Federation and the Canadian Nature Federation bring issues about biodiversity to our governments’ attention. ↳ Some organizations also support conservation efforts financially or through active participation in conservation efforts. 16 of 16