Multicellular Diversity Sections 3.4 – 3.5

3.4 - The Animal Kingdom

Complete the K/W/L Chart on the Animal Kingdom What I know What I Want to Know What I Learned

What is an Animal Animals have several characteristics that make them different from other organisms What do you think some of them are?

What is an Animal ? In general, all animals share the following characteristics: They are Eukaryotic, multicellular organisms. Their cells DO NOT have cell walls They are heterotrophs, that ingest and digest their food They are mobile in at least one phase of their life They reproduce sexually and produce an embryo that undergoes stages of development

Classifying Animals One way to classify an animal is whether or not it has a backbone With and internal skeleton = vertebrates (5%) WITHOUT = invertebrates (95% of animals) Other characteristics include: Levels of organization # of body layers Symmetry and body plans Body cavity Movement Reproduction / DNA segmentation

Invertebrate Animals Take up almost all terrestrial and aquatic ecosystems on earth Sponges Cnidarians Worms Molluscs Echinoderms Found in marine / freshwater environment Their bodies are made up of 2 layers of cells As adults they feed by trapping food particles in water as it passes through internal channels of their body Contain corals, jellyfish, and freshwater hydras Only have 2 layers of cells, but HAVE muscle tissues and a nervous system Able to swim and capture prey by using stinging tentacles Food is digested in their body cavity Flatworms – 3 layers of cells, with a simple nervous system Segmented – more complex, with long tube bodies and many organ systems within Have bilateral symmetry, 3 layers of cells and two body openings Have a soft body protected by hard exterior shells Include clams, mussels, oysters, and scallops Include star fish, sea urchins, sea cucumbers, and sand dollars Marine animals with radial symmetry and tube feet Have an endoskeleton made up of calcium carbonate

Arthropods Make up the majority of the animal phylum Include things like spiders, scorpions, crustaceans, and insects Have a large exoskeleton that helps protect the animal

Vertebrates There are roughly 50 000 species of vertebrates that are divided into 5 major classes Fish Amphibians Reptiles Birds Mammals Found in salt and fresh water Further divided whether or not they have jaws and fins or NOT Found with 2 pairs of limbs (hands / feet) The diversity of these limbs have ↑over time Tied to wet ecosystems Changes to ecosystems due to human activity ↓ their habitat and increase presence of disease Dated back 300 million years ago to early dinosaurs Include lizards, snakes, turtles & crocodiles Have body scales that create a waterproof barrier that prevents them from being dehydrated in HOT climates Fertilization occurs internally after an egg and sperm join, many layers of membrane develop around the egg This egg is later deposited in heat generated area Have 4 chamber hearts like mammals Have high body temperatures Most can fly, with weight saving adaptations for flight i.e. light bones, toothless skull and low body weight – making it easier to fly MOST distinctive feature = mammary glands that secrete milk Have hair: useful for warmth, camouflage, waterproofing, communication have highly developed brains Grouped – monotremes, marsupials, placental mammals,

The biodiversity crisis Section 3.5 The biodiversity crisis

Terminology Mass extinction – a large scale dying out of a large percentage of all living organisms within an area over a short time Biodiversity crisis – the current decline in genetic, species, and ecosystem diversity that may represent a mass extinction http://www.biologicaldiversity.org/programs/biodiversity/elements_of_biodiversity/extinction_crisis/

Threat of Climate Change Species can have threats to their: habitat, competition for food availability, hunting / trade by humans, destruction via pollution & climate change Climate change – looks at change in patterns of precipitation and temperature; which can affect many species in an area Atmospheric Scientist study the trends of climate change over time, where they are able to make predictions for an ecosystem through a modeling system

Climate Change & Food Sources Changes in climate (global warming) can lead to changes in ecosystems, where prey / vegetation are no long available to animals (predators) to feed on This can cause predators to migrate from such environments to somewhere else that food is available, or they can die in the longing for such food sources (if unsuccessful) Ex. The Caribou population in Canada

Climate Change & Habitat Global warming has contributed to changes in altitude and vegetation zones in mountainous regions The warmer it gets … the upper zones become smaller and risk being eliminated

Climate Change & Reproduction In many reptile species, the temperature at which the eggs are incubated determines the sex of the off spring Where: the eggs of several species (not all!) produce females when temperatures are relatively warm and males when temperatures are cooler. Thus, with global warming = production of more female eggs Question .. How does the production of more females affect a species’ population?

Climate Change, Plants & Animals Part of the success of the relationship between a plant and its pollinator depends on timing The pollinator must be at the right stage of its life cycle to be at the right place and pollinate plant flowers Unfortunately, with global warming, this natural cycle can cause a plant to flower earlier or for a pollinator to become active earlier than “normal” timelines

Climate Change & Aquatic Ecosystems Increasing temperatures associated with climate change also affect freshwater organisms For example – looking at Rainbow Trout in Lake Ontario over the last few years, we see how warmer summer waters and warmer winter waters resulted in a reduced growth rate of fish and their consumption of oxygen increased

Review https://www.youtube.com/watch?v=g9AQbkQgVeU

Remaining Time Complete your Chapter 3 Assignment Study for Unit 1: Diversity of Living Things TEST!