Tuesday, 25 August 2015
Tuesday, 30 June 2015
Plants, also called green plants, are multicellular eukaryotes of the kingdom Plantae. They form a clade that includes the flowering plants, conifers and other gymnosperms, ferns, club-mosses, hornworts, liverworts, mosses and the green algae. Plants exclude the red and brown algae, the fungi, archaea, bacteria and animals. There are suspected to be 300 to 315 thousand species of plants, of which the great majority are seed plants. (gymnosperms and angiosperms)
Plants, like other life forms in the Eukaryota domain, have cells with membrane-bound organelles.
Plants are made up of many cells, each serving different specific functions within the plant. All plant cells have cell walls made up of cellulose and a singular large central vacuole. Cell walls provide the cell with structural support, preventing them from bursting from large quantities of water entering the cell.
Plants are able to make their own food due to a process called photosynthesis carried out by the green pigment chlorophyll. Leaves are primary site of this process, where plants use water and carbon dioxide to convert light energy into sugars, releasing oxygen as a by-product. These sugars are used to power many metabolic processes within the plant with another process called respiration. This positions plants at the bottom of the food web, as heterotrophs like animals need to consume plant/animal matter to survive. An exception of this rule are holoparasitic plants, which contain no chlorophyll and thus cannot make their own food. Instead, they rely on other organisms to provide them with energy. (rafflesia, dodder plants)
- Soil Reliance
Most plants rely on a form of soil for support and water. Plants grow roots into soil, anchoring them and absorbing water. The soil also provides the plant with varying amounts of minerals, depending on soil composition. Some plants supplement their water resources with aerial roots that capture moisture from the air (orchids), and nitrogen by capturing and digesting small animals. (venus flytrap, pitcher plant)
Like animals, plants use energy stores (sugars generated from photosynthesis) and oxygen to release energy that powers metabolic functions. This process of respiration releases carbon dioxide as a by-product.
done by Jin Yu, Roy, Wai Yan, Noel, and Sid
Kingdom Animalia is also known as Metazoa. This kingdom does not contain prokaryotes and all the members of this kingdom are multicellular eukaryotes. They are heterotrophs and they depend on other organisms directly or indirectly for food. Most of the animals ingest food and digest in the internal cavity. Most of the organisms are motile which means they can move independently and spontaneously.
There are around 9 to 10 million species of animals, and about 800,000 species are identified.
Characteristics of the kingdom Animalia
- Complex Eukaryotic cells
- Animals are made up of organised eukaryotic cells from the zygote stage. Cells then gradually differentiate into different tissues to provide specialised structure or functions.
- Tissue Specialisations
- Animals are multi-cellular. Various tissue and organ systems are constructed to provide specialised functions for day-to-day survival of the species.
- Animals are Aerobic
- Aerobic metabolism is the means where animals break down food and acquire energy needed for their functions.
- Sexual reproduction
- The survival of most animal species is accomplished through sexual reproduction.
- Most animals are capable of movement – this property of motion is highly dependent upon the development of a stimulable skeletal-muscular system.
- Varies in Size
- The sizes of animals ranges from a few celled organism to animals weighing many tons.
- Respiration is a gaseous exchange of taking in oxygen and giving out carbon dioxide. This process takes place in organs of respiration.
- Animals ingest food, and digestion takes place in the internal cavity like the digestive system in animals, in primitive animals vacuoles are for digestion.
- Nervous system
- Sensory mechanism and the coordination of the organ systems is carried on by the nervous system. In animals the nervous system comprises of nerve ganglions, or brain, spinal cords and nerves.
- Circulatory system
- The distribution of nutrients, exchange of gases and removal of wastes takes place in the circulatory system. This system comprises of the heart, blood vessels and the blood.
- Excretory system
- Removal of wastes from kidneys.
- Skeletal system
- The skeletal system supports the animal, and provides protection.
Activity 2: Key Characteristics of the Organisms in the 5 Kingdoms
Special Characteristics of the Kingdom Animalia - Invertebrates and Vertebrates
done by: nishtha, durwa, wei-san, clement, everi
done by: nishtha, durwa, wei-san, clement, everi
There are around 9 to 10 million species of animals, and about 800,000 species are identified. Fossil records of animals were found in the era of the Cambrian explosion, about 540 million years ago. Animals are divided into various sub-groups, biologists have identified about 36 phyla within the animal kingdom including birds, mammals, reptiles, fish, amphibians etc.
- Animals are eukaryotic (organisms whose cells contain a nucleus and other organelles enclosed within membrane), multicellular and heterotrophic (organisms that cannot manufacture its own food and instead obtains its food and energy by taking in organic substances, usually plant or animal matter).
- Habitat - Most of the animals inhabit seas, fewer are seen in fresh water and even fewer on land.
- Size - The sizes of animals ranges from few-celled organism like the mesozoans to animals weighing many tons like the blue whale.
- Animal bodies - Bodies of animals are made of cells organized into tissues which perform specific functions. In most animals, tissues are organized into complex organs, which form organ systems that aids in performing specific functions and then a whole body.
- Cell structure - The animal cell contains organelles like the nucleus, mitochondria, Golgi complex, ribosomes, endoplasmic reticulum, lysosomes, vacuoles, centrioles, cytoskeleton which all have specific functions to do.
- Body symmetry - Most of the animals are bilaterally symmetrical, while primitive animals are asymmetrical and cnidarians (jellyfish for example) and echinoderms (starfish for example) are radially symmetrical.
- Locomotion - Most animals are motile, they show rapid movement when compared to plants and other organisms.
- Some animal’s skin is also used for respiration.
- Digestion - Animals ingest food, and digestion takes place in the internal cavity like the digestive system in animals. In primitive animals, vacuoles are for digestion.
- Most animals reproduce sexually, by the fusion of haploid cells like the eggs and the sperms.
- Invertebrates do not have a backbone, are the simplest of animals, greatest in number, most are found in water, some have exoskeleton (like starfish) and others have no skeleton (annelids).