SUMMARY
CHAPTER 1
1. Living things can undergo nutrition, growth, excretion, respiration, movement, irritability,
and reproduction, while non-living things such as a car may only perform some of them.
2. All organisms are given a specific and generic name for identification, written in italics.
3. Organisms are classified into the main groups, viruses, bacteria, algae, protozoa, and fungi,
that are mainly microorganisms and then the larger plants and animals.
4. A human is an animal, a vertebrate (having a backbone) and a mammal named Homo
sapiens.
5. Mammals have mammary glands, hair, a diaphragm and sweat glands and bring young alive.
6. Humans’ special features are their large brain, providing high intelligence and conscious
thought vocal cords for speech being bipedal to free the hands and an opposable thumb for
gasping and tool making.
CHAPTER 2
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The basic units of organisms are cells, only visible through a microscope.
Protoplasm has two main parts: the cytoplasm and the nucleus.
The cell organelles are the mitochondria for respiration, endoplasmic reticulum for transport,
ribosomes for protein synthesis, not in animal cells.
Diffusion is the movement of molecules or ions, from a higher concentration to a lower
concentration.
Osmosis is the passage of water through a partially permeable membrane from a weaker to
a more concentrated solution.
Active transport is the movement of substances across cell membranes using energy from
cell respiration.
Cell homeostasis means the cell contents remain the same. Selective passage by active
transport keeps the contents the same.
Substances enter and leave the cell by diffusion, osmosis, and active transport.
Metabolism is all the chemical reactions occurring in the cell.
A group of cells form a tissue, tissues together form organs, that together make up the
systems of the body.
The body cavity has the thorax containing the digestive, urinary, and reproductive systems.
CHAPTER 3
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The food for all organisms is first made by photosynthesis.
A food chain links the organisms through which food is passed in a community. Each link
feeds on the one before it and is in turn eaten by the one following it.
Food chains start with plants (primary producers), then herbivores, then carnivores.
A trophic level contains all organisms that feed on the same type of food.
Pyramids of numbers, biomass and energy show the content and flow between trophic levels
in a habitat.
The loss of energy between trophic levels makes animal protein food expensive.
Photosynthesis is the manufacture of sugar, from carbon dioxide and water, in the
chlorophyll of plants, using the energy from sunlight, with the release of oxygen.
The sugar produced forms carbohydrates that may combine to make fats or combine with
nitrates to make protein.
Photosynthesis summary equation:
𝑙𝑖𝑔ℎ𝑡 𝑎𝑛𝑑 𝑐ℎ𝑙𝑜𝑟𝑜𝑝ℎ𝑦𝑙𝑙
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6𝐻2 𝑂 + 6𝐶𝑂2 →
𝐶6 𝐻12 𝑂6 + 6𝑂2
The carbon cycle – the circulation of the element carbon:
1. Carbon dioxide in the air forms compounds in the plants by photosynthesis.
2. Carbon compounds enter animals when they eat plants.
3. Plant and animal respiration, and combustion, returns carbon dioxide in the air.
The nitrogen cycle – the circulation of the element nitrogen:
1. Nitrates absorbed from soil form protein in green plants.
2. Animals make plant protein from animal protein eaten.
3. Animal protein is broken down to urea (released as urine).
4. Bacteria convert urea, dead plants and animals to ammonium compounds, then to
nitrites then to nitrates in the soil.
5. Soil also receives nitrates from atmospheric nitrogen by nitrogen fixing bacteria.