Russia 8 класс Biology (basic)
Chapters: 6
1. Animal organism
Zoology and features of animals · Animal cell and tissues
- Tissues: Plant and Animal Tissues – A tissue is a group of similar cells that do one job together. Cells form tissues, tissues form organs, organs form organ systems and systems form an organism. Plants have dividing meristematic tissue and non-dividing permanent tissue, including xylem (water up) and phloem (food both ways). Animals have epithelial, connective, muscular and nervous tissue. Bones, muscles and joints need good posture, exercise and food rich in calcium.
2. Structure and life processes of animals
Support and movement · Nutrition and digestion · Respiration · Transport of substances · Excretion · Body coverings · Coordination and regulation · Behaviour · Reproduction and development
- The Skeletal System – The skeleton is the body's frame of 206 bones (adult). It has five main jobs: support and shape, protection, movement (with muscles), making blood cells in red marrow, and storing minerals like calcium. Bones meet at joints; hinge joints (elbow, knee) bend one way, ball-and-socket joints (shoulder, hip) move in all directions. Ligaments join bone to bone, tendons join muscle to bone, cartilage cushions the ends. Muscles only pull, so they work in antagonistic pairs such as biceps and triceps.
- Transportation in Humans: Heart, Blood Vessels, Blood and Lymph – The heart is a four-chambered muscular pump. Blood passes through it twice in one full round: once to the lungs to pick up oxygen, and once to the rest of the body. This is double circulation. Arteries carry blood away from the heart, veins bring it back and capillaries do the exchange. Blood (plasma, RBCs, WBCs, platelets) and lymph together carry food, gases, hormones and wastes.
- Nervous System, Reflex Action and the Human Brain – Nerve cells (neurons) carry messages as electric impulses and pass them to the next cell with chemicals across a gap called a synapse. Quick safety responses (reflexes) are handled by the spinal cord; thinking and control come from the brain, which is guarded by the skull and a fluid cushion.
- Animal Behaviour: Why Animals Do What They Do – Behaviour is everything an animal does in reply to a stimulus from outside (a predator, light, a sound) or inside (hunger, hormones). Some behaviour is innate (instinct, born with it); some is learned (habituation, conditioning, imprinting, insight). Behaviour has a function: it helps the animal survive and reproduce, often by living in groups. Many animals are sentient: they can feel pain, fear and pleasure.
- Reproduction in Human Beings and Reproductive Health – At puberty, hormones from the brain make the testes and ovaries start working. The male system makes and carries sperm; the female system makes eggs and provides a place (uterus) where a baby develops. Fertilisation happens in the oviduct, and the embryo is fed through the placenta. Reproductive health includes safe choices, contraception, avoiding female foeticide, and preventing sexually transmitted diseases such as HIV/AIDS.
- How Do Organisms Reproduce? DNA Copying and Asexual Reproduction – Reproduction makes new individuals by copying DNA. The copies are never perfect, and these small changes (variations) help a species survive when its surroundings change. In asexual reproduction a single parent makes offspring by fission, fragmentation, regeneration, budding, vegetative propagation or spores.
- Sexual Reproduction in Flowering Plants – Sexual reproduction joins a male and a female gamete, mixing DNA from two parents and creating more variation. In a flower, pollen from the anther reaches the stigma (pollination), grows a pollen tube to the ovule, and the male gamete fuses with the egg (fertilisation). The zygote becomes the embryo, the ovule becomes the seed and the ovary becomes the fruit.
3. Systematic groups of animals
Animal classification · Protists · Cnidarians · Worms · Arthropods · Molluscs · Chordates · Fish · Amphibians · Reptiles · Birds · Mammals
- Diversity and Classification of Living Organisms – Earth has millions of kinds of living things, and India is one of the richest places. To study them, we sort them into groups by asking simple questions about their bodies: Is there a nucleus? One cell or many? Can it make its own food? This gives five kingdoms: Monera, Protista, Fungi, Plantae and Animalia. Animals split into invertebrates and vertebrates. Every species gets a two-part scientific name. Viruses are not cells, so they fit in no kingdom.
- Protists: Living Things Made of One Cell With a Nucleus – Protists are mostly single-celled living things whose cell has a true nucleus (they are eukaryotes). Animal-like protists (protozoa) such as amoeba and paramecium hunt food; plant-like ones such as euglena and diatoms make food in light; fungus-like ones such as slime moulds absorb food. They move with pseudopods, cilia or flagella, keep water out with contractile vacuoles, multiply by splitting and survive bad times as cysts. Some cause disease: malaria, giardiasis, toxoplasmosis, trichomoniasis.
- Arthropods: Insects, Spiders and Crabs – Arthropods are animals with jointed legs, a hard outer skeleton and a body in segments. They must moult to grow. Insects have 6 legs and 3 body parts, arachnids (spiders, ticks, scorpions) have 8 legs and 2 parts, and crustaceans (crabs, shrimps) usually have 10 legs and 4 antennae.
- Molluscs: Snails, Clams and Squids – Molluscs are soft-bodied animals with a muscular foot and a cloak called the mantle. Most make a hard shell. The three big groups are gastropods (snails, one shell), bivalves (clams, two shells) and cephalopods (squid and octopus, shell inside or none).
4. Evolution of the animal world
Evolution of animals
- Evolution: How New Kinds of Living Things Arise – Variations arise during reproduction. Nature selects those that help survival, so over many generations populations change: this is evolution. Only inherited (DNA) changes pass on; acquired changes do not. Separated populations can become new species. Homologous organs, analogous organs and fossils help us trace who is related to whom, and complex organs evolved step by step.
5. Animals in communities
Animals and environment · Animals of natural zones
- Ecosystem, Food Chains and Energy Flow – An ecosystem is all the living things in a place plus the non-living things around them, working together. Energy enters as sunlight, passes one way up a food chain, and only about 10% moves to each next level.
- Biomes and Forests: Life on Earth – A biome is a large region with a similar climate, plants and animals, like tundra, taiga, grassland, desert, savanna and tropical rainforest. Rain and temperature decide which biome forms. India protects special areas as biosphere reserves, which have a core, buffer and transition zone. Forest dwellers depend on forests and know how to use them without harming them; ecotourism can give them income. We conserve forests and wildlife through national parks, sanctuaries, laws and people's movements like Chipko, and we must prevent forest fires.
6. Animals and people
Human impact on animals
- Animals, People and Conservation – People have changed animal life for thousands of years: we hunt and fish, we tamed wild animals and bred them into many breeds, we fight pests and share cities with urban animals. When we take more than nature can replace, species decline and may go extinct. Conservation means using animals wisely and protecting them: Red Books list species in danger, national parks protect land, and marine protected areas and fishing rules protect the ocean.