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生物学 · 概念课

从第一原理掌握 生物学

细胞、遗传学、生态学、进化和身体系统。覆盖TEKS §112.34。

1

Cell Structure & Organelles: A Tour Inside the Cell

Every Texas Biology CBE has at least one organelle-identification question. Master the eight structures every cell biology question is built around — what each one looks like, what it does, and how plant cells differ from animal cells.

9 分钟 TEKS 4A,4B,5D 81
2

Cell Membrane & Transport: How Things Get In and Out

The cell membrane is the boundary that decides what enters and leaves. Master the phospholipid bilayer, transport proteins, osmosis, diffusion, and active transport in one focused lesson.

8 分钟 TEKS 4B,5D 55
3

Cell Cycle & Mitosis: How One Cell Becomes Two

The CBE tests both the cell cycle macro-phases (G1/S/G2/M) and the mitosis substages (Prophase, Metaphase, Anaphase, Telophase). Master both levels and how they connect.

9 分钟 TEKS 5B,5C 57
4

Mitosis vs Meiosis: Two Divisions, Two Outcomes

Mitosis and meiosis sound similar but serve completely different purposes. Master the four key differences (cell count, ploidy, purpose, genetic identity) and you'll never miss a comparison question.

8 分钟 TEKS 6A,6B 53
5

DNA Structure & Replication: The Code of Life and How It Copies Itself

Three things every CBE asks: the four bases (A, T, G, C) and how they pair, the double helix structure, and semi-conservative replication. Plus the four enzymes that make replication work.

9 分钟 TEKS 6B,6C,6D 60
6

Genetics & Punnett Squares: Predicting Inheritance with a 2×2 Grid

The Punnett square is the single most-tested tool on the Biology CBE. Master monohybrid crosses, dihybrid crosses, and the four key terms — homozygous, heterozygous, dominant, recessive.

10 分钟 TEKS 6E,6F,6G 64
7

Evolution & Natural Selection: How Populations Change Over Time

Natural selection isn't 'survival of the strongest' — it's differential reproduction based on heritable variation. Master Darwin's mechanism, the evidence for evolution, and the famous Galápagos finches.

9 分钟 TEKS 7A,7B,7C,7D,7E 54
8

Ecology: Food Webs, Trophic Levels & Energy Flow

Producers, primary consumers, secondary consumers, tertiary consumers, decomposers — and the 10% rule that connects them. Master food chains, food webs, and energy pyramids in one focused lesson.

10 分钟 TEKS 11A,11B,12A,12C,12F 64
9

Biogeochemical Cycles: Carbon, Water & Nitrogen

Atoms cycle through ecosystems endlessly. Master the carbon cycle (photosynthesis ↔ respiration), the water cycle (evaporation/precipitation), and the nitrogen cycle (fixation + denitrification).

8 分钟 TEKS 12B,12C 49
10

Classification & Human Body Systems

Two big topics in one lesson: the taxonomic hierarchy (Domain → Species), the three domains of life, and the human body systems most-tested on the CBE — respiratory and circulatory.

9 分钟 TEKS 8A,8B,8C,9A,9B,10A,10B 53