Russia 7 класс Biology (advanced)
Chapters: 4
1. Introduction
Cytology and cell theory
- The Cell: Basic Unit of Life – Every living thing is made of cells. Robert Hooke first saw cells in cork in 1665. Cells are prokaryotic (no true nucleus, like bacteria) or eukaryotic (true nucleus). Plant cells have a cell wall, chloroplasts and a big vacuole; animal cells do not. Each organelle has a job. Water enters and leaves cells by osmosis. Cells make new cells by mitosis (growth) and meiosis (sex cells).
2. Bacteria and archaea
Prokaryotes
- Bacteria: Tiny Cells That Run the Planet – Bacteria are single-celled prokaryotes: they have no nucleus and no membrane-bound organelles. Their DNA is one circular loop (the nucleoid), often with small extra rings called plasmids. They have 70S ribosomes, a cell membrane, a cell wall of peptidoglycan, and may have a capsule, pili and flagella. Shapes: coccus, bacillus, spirillum, vibrio. They reproduce by binary fission and can swap genes sideways by conjugation, transformation and transduction. They feed by photosynthesis, chemosynthesis, decomposition, symbiosis or parasitism, and drive the carbon and nitrogen cycles. Archaea look similar but differ in wall and membrane chemistry and often live in extreme places.
3. Unicellular eukaryotes
Protists
- 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.
4. Archaeplastids (plants)
Botany and plant organisation · Algae · Spore plants · Seed plants · Shoot, bud, stem · Leaf · Root and soil · Vegetative propagation · Classification of flowering plants · Plant ecology · Plants and people
- 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.
- Algae – Algae are simple living things that live mostly in water and make food from sunlight. They have no true roots, stems or leaves. They can be one cell or very long. Green, brown and red algae have different pigments. They make oxygen and feed water animals.
- Flowering Plants (Angiosperms) – Angiosperms are plants that make flowers, and their seeds grow inside fruits. They are split into two groups. Dicots have 2 seed leaves, taproot, net-veined leaves and flowers in 4s or 5s. Monocots have 1 seed leaf, fibrous roots, parallel veins and flowers in 3s.
- Life Processes and Photosynthesis – Life processes are the jobs every living body must keep doing to stay alive: nutrition, respiration, transport and excretion. Green plants do nutrition by photosynthesis: using sunlight and chlorophyll, they turn carbon dioxide and water into glucose and give out oxygen.
- 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.
- 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.