Russia 8 класс Biology (advanced)

Chapters: 5

1. Fungi and fungus-like organisms

Fungi

Fungi: Mushrooms, Moulds, Yeast and Lichens – Fungi are living things with cells that have a nucleus and a cell wall made of chitin. They have no chlorophyll, so they cannot make food. Most are made of thin threads called hyphae; a net of hyphae is a mycelium. Fungi pour digestive juices onto food and absorb what dissolves. They spread by tiny spores. Mushrooms, moulds and yeast are fungi. A lichen is a fungus living together with an alga.

Zoology · Animal cell and tissues · Nutrition, transport, respiration · Excretion and osmosis · Support and movement · Regulation

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.
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.
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.

Two- and three-layered animals · Flatworms, roundworms, annelids · Molluscs · Arthropods

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).
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.

Chordate features and lancelet · Vertebrates

Coming soon

Evolution of animals · Habitats and adaptations · Animals and people

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.
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.
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.