Revision Powerpoint.pptx

Revision PowerPoint for Science By ThommyG  Ecosystems Ecology, Biomes, Biotic and Abiotic Factors, Population, the Biotic Relationships, Adaptations, Food Chains/Webs, Trophic Levels, Human Impacts, and Biodiversity Ecology Ecology is a branch of biology rel...

Revision PowerPoint for Science By ThommyG  Ecosystems Ecology, Biomes, Biotic and Abiotic Factors, Population, the Biotic Relationships, Adaptations, Food Chains/Webs, Trophic Levels, Human Impacts, and Biodiversity Ecology Ecology is a branch of biology relating to the study of ecosystems The environment consists of all the factors in an organisms surrounding that affect it The habitat is where a species or organism resides within an environment The biosphere entails all life on earth The levels of ecology can be seen in the diagram to the right Biomes A biome is an area classified by its factors (see next slide), including vegetation, temperature, climate Biomes fall into classes, and then further into types The classes of biomes are marine (ocean), and terrestrial (land) The main types of biomes are grassland, forest, shallow ocean, deep ocean, and desert (including most snow areas) Biotic and Abiotic Factors Biotic factors are any living thing in an ecosystem (any species that follows the basic seven life processes, with those being; movement, reproduction, sensitivity, nutrition, excretion, and growth) Abiotic factors are any nonliving factor in an ecosystem (for example, sunlight, temperature, water, rocks, etc.) All living things have a tolerance range, which is the range they can survive biotic and abiotic factors The tolerance range is directly influenced by biotic and abiotic factors The Biotic Relationships There are 5 biotic relationships between communities, and they are: Competition, which is when organisms compete for mates or food Predation, which is when one organism kills another for food Parasitism, which is a relationship between 2 organisms where 1 benefits and the other is harmed Mutualism, which is which is a relationship between 2 organisms where both benefit Commensalism, which is when a relationship between 2 organisms where 1 benefits and the other gets nothing Population A population is a group of organisms of the same species living in the same ecosystem Populations can be measured through size, density, distribution, birth and death rates, and composition These measurements are found through sampling Examples of sampling include quadrats (small areas of habitats), transects (a line on a map that intersects a habitat), and mark and recapture (tracking an animal’s location), among others Adaptations An adaptation is a special characteristic that allows an organism to survive a particular environment Adaptations may be classified through morphology (physical body change), physiology (internal organ change), or behavioral (behavior change) Organisms that live in a variety of different habitats will have more adaptations than organisms that live in one habitat Organisms adapt according to biotic and abiotic factors Food Chains/Webs Energy flows through an ecosystem in one direction from the sun (or inorganic compounds) to autotrophs (producers), and then to heterotrophs (consumers) Food chains simply start with the producer and end with the top carnivore in a line, whereas food webs are complex networks of food chains in an ecosystem Food chains and webs are based off of what eats/consumers others Key species are species in a food chain/web that determine a species composition – other species in the ecosystem depend on the keystone species for survival It is important to note that food chains/webs also include decomposers (which is where wasted energy such as cellular respiration excess and excretion go to) Trophic Levels There are four trophic levels, and they are steps in food chains/webs Trophic Level 1: Producers, such as plants Trophic Level 2: Primary Consumers, usually herbivores Trophic Level 3: Secondary Consumers, usually omnivores but sometimes carnivores Trophic Level 4: Tertiary Consumers, the apex predator, usually the top carnivore Human Impacts Natural impacts are changes due to natural events, such as natural disasters (droughts, floods, etc.) Human impacts are changes due to unnatural events, including habitat destruction (land clearing, mining, logging), introduced species (species brought in from overseas which can kill native species), chemical pesticides (chemicals that kill insects and can have a negative impact on ecosystems), chemical pollution (such as oil), and over – cropping (eating more foods than is suitable for the environment) Biodiversity Biodiversity is the diversity of life in an ecosystem Genetic diversity is the variety of genes within a species Species diversity is the different species and their abundance in an ecosystem In an ecosystem the higher the species diversity the more likely the ecosystem is to be resilient (surviving harsher conditions and changes) Ecosystem diversity is the number of different ecosystems in a biome Biodiversity Continued When measuring biodiversity there are a few key concepts: Species richness is the number of different species in an area (not the number of each species) Species evenness is a measure of the number of individuals of a particular species in relation to the number of all species in the same area When several species evenness and richness increase, the biodiversity of an area increases and vice versa Simpsons Diversity Index (SDI) is a measure of biodiversity that consists of both species' evenness and richness (with high SDI being high biodiversity and low SDI meaning low biodiversity) SDI is used to compare the same community over time or to compare different communities Extra Info Cellular respiration is the process in which living things use oxygen and sugar to get energy. With cellular respiration, carbon dioxide and water and the resultants. Biomagnification is the concentration of heavy metals, pesticides, or organochlorides (chemicals) in organisms. Biomagnification can affect an entire ecosystem. Animals lose heat from the body surfaces that are in contact with the surrounding air/water. Reducing the surface area (contact surface) reduces heat loss and vice versa. Cold climates usually have a small ratio of surface area to volume to preserve heat while warm climates usually have a larger ratio to lose heat. The Nervous System Functions of the Nervous System, the Central and Peripheral Nervous Systems, Autonomic and Somatic Systems, Neurons, Reflex Arcs, and the Brain Functions of the Nervous System The Nervous System has 3 main functions: Collection of sensory input by receptor cells, which identifies changes occurring inside and outside the body Integration, which processes, analyses, and interprets these changes and makes decisions accordingly Motor Output, which effects a response by activating muscles or glands (muscles and glands are called effectors, ) The Central and Peripheral Nervous Systems The Nervous System is split into 2 major groups: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS) The CNS, consisting of the brain and spinal cord, collects sensory input from the PNS and responds appropriately The PNS connects the CNS to the rest of the body and is responsible for collecting sensory input Autonomic and Somatic Systems The PNS can be further broken down into the Autonomic and Somatic systems The autonomic system consists of parasympathetic (rest and digest) and sympathetic (fight or flight) nervous systems The Somatic nervous system consists of the Sensory Nervous System (senses changes) and the Motor Nervous System (the effector which acts out the decision made) Neurons Neurons are specialized cells that transmit information Neurons stop reproducing shortly after birth, meaning that usually when they die, they are not replaced There are 3 types of Neurons which are all connected: Sensory Neurons, which carry sensory impulses from sensory organs to the CNS Interneurons, which transmit information between other neurons Motor Neurons, which carry motor impulses from the CNS to effectors (muscles and glands) A synapse is a neurotransmitter released into the space between neurons Neurons (continued) Neurotransmitters carry the message from the axon terminal of one neuron to the dendrites of another neuron (see diagram) The diagram shows the parts of a neuron, with those being the dendrite, the nucleus, the axon, the myelin sheath, and the axon terminal, with each having a purpose of assisting the transmission of neurons Reflex Arcs Receptor Cells are specialized cells that respond to a stimulus Effector cells are cells in muscles or glands that put messages into action A reflex arc is the reflex action to a stimulus and work through the following steps: The sensory receptor cells detect the stimulus and the sensory neuron carries the information in the form of a nerve impulse to the spinal cord An interneuron in the spinal cord passes the impulse from the sensory neurons to the motor neurons The motor neurons carry the nerve impulse to the muscle The muscle contracts and responds accordingly The Brain The Endocrine System Function and Definitions, Important Parts and their Function, ADH, Blood Sugar, and Diabetes Function and Important Definitions The endocrine system produces hormones which regulate metabolism, growth and development, sexual function, reproduction, sleep, and mood The endocrine system is linked with the nervous system, with some of its parts being a part of both systems The endocrine system is essentially a communication system in the body made up of glands Hormones are chemical substances that act as messengers in the body and are transported through the bloodstream Homeostasis is the process of the body being internally stable constantly In body systems, endothermic means it can stay at 37° Celsius – animals that are endothermic are warm blooded Ectothermic means the body cannot maintain a constant temperature – ectothermic animals are cold blooded Important Parts and their Function (and location) The important parts of the endocrine system are:  The hypothalamus, which is the link between the endocrine and the nervous systems  The pituitary gland, which produces and regulates growth hormones  The pancreas, which produced hormones which manage blood sugar  The thymus, which produces t cells which defend against viruses  The adrenal, which produces adrenaline for a fight or flight response  Ovaries and testis (females and males respectively) which produce sexual hormones A few other glands and important parts of the endocrine system that don’t play as major a role are the pineal gland and the thyroid gland ADH ADH stands for Antidiuretic hormone ADH is produced by the hypothalamus and released by the pituitary gland Different amounts of ADH are released into the bloodstream depending on the concentration of water in the blood plasma The more water in the blood plasma the less ADH is released and vice versa Less ADH results in less water being reabsorbed in the kidney and more urine being excreted Alcohol inhibits the pituitary gland from secreting ADH, hence increasing urine excretion Blood Sugar The Pancreas releases hormones insulin and glucagon Unused glucose (sugar) is stored in the liver as glycogen When blood sugar rises, insulin is released, causing more glucose to be released and the blood sugar to return to normal, and when blood sugar drops too low glucagon is released, causing the liver to release stored glycogen back to glucose The pancreas releases insulin to help the body store and use the sugar and fat from the food you eat Diabetes Diabetes are a problem that result due to issues with the insulin hormone Diabetes occur either when the pancreas doesn’t produce any or enough insulin, or when the body does not respond appropriately to insulin (a condition called insulin resistance) There are 2 types of diabetes: Type 1: Occurs when insulin produced is none or not enough and happens because the immune system destroys insulin producing cells. Those with type 1 require insulin injections. Type 2: Occurs when the insulin secreted by the pancreas is either not enough or the body has the before mention insulin resistance condition  Criteria Ecology Nervous System Define an ecosystem Differentiate between the central -Endocrine System nervous system (CNS) and the -List and describe the functions of the Describe how biotic and abiotic factors interact in peripheral nervous system (PNS) endocrine system an ecosystem -Identify the location of the major Identify the location of the Identify a food chain in a food web following parts of a brain, and glands/organs that make up the endocrine identify two functions of each systems and list the specific hormones that In a food chain or food web, identity producers, Cerebrum (or cerebral they produce consumers and decomposers, and describe the role of each in an ecosystem. cortex) hypothalamus Cerebellum pineal gland Describe how the absence or abundance of certain Brain stem pituitary gland organisms in a food web affects other organisms Corpus callosum thyroid Define biodiversity and explain how biodiversity is Pituitary gland adrenal glands related to the resilience of an ecosystem. Recall the main features of a pancreas Identify adaptations as either physical or neuron (cell body, nucleus, ovaries behavioural dendrites, axon, myelin sheath) testes Recall the direction of travel of -Describe what hormones are Analyse predator -prey relationships message in a neuron and explain their role in our bodies Recall that competition exists in any Recall that there are three different -Explain what homoeostasis is and how the ecosystem because resources are limited types of neurons (sensory, endocrine system helps to maintain it. interneuron or relay and motor -Describe and explain specific ways the Compare the three types of symbiotic relationships (mutualism, commensalism, and parasitism) neuron) endocrine system maintains homoeostasis Explain (in simple terms) what through the following feedback loops: body Analyse (graphically) the three types of symbiotic happens in synapses temperature, water-levels, blood-sugar, relationships Explain stimulus-response stress Describe how energy is transferred through a food pathways using nervous systems chain (including reflex arcs) Explain how matter enters and leaves the food Compare a stimulus response chain pathway and a reflex arc Recall the five primary types of Explain how matter cycles through ecosystems receptors (photoreceptors, Describe some way in which humans impact mechanoreceptors, pain receptors, ecosystems thermoreceptors, photoreceptors) Quiz Link by Shon QUIZ ECOLOGY By Shon and Thomas | Quizizz