Memorize these and you could recognize 22.5% of all Biology clues.
| # | Answer | Appearances | Sample Clue |
|---|---|---|---|
| 1 | teeth | 8 | Some birds still have the gene that would allow these to grow in their beaks |
| 2 | chlorophyll | 7 | Plants are green because this substance absorbs blue-violet & red light |
| 3 | amino acids | 7 | Types of these, like ornitthine, link up to form proteins |
| 4 | the stomach | 6 | This human organ secretes the enzyme pepsin |
| 5 | DNA | 6 | It's hereditary material in the form of 2 coiled polynucleotide chains that form a double helix |
| 6 | the heart | 5 | In mammals, it's a muscular, pulsatile pump with valves |
| 7 | the epidermis | 5 | Among animals, this outer layer of cells, such as skin, generally insures that the body is waterproof |
| 8 | chromosomes | 5 | Humans typically have a set of 46 in most of their cells |
| 9 | = | 5 | = |
| 10 | cells | 5 | Dendrites are projections from this type of cell |
| 11 | the amoeba | 5 | Facts on File calls this irregular-shaped single-celled organism the best known of the protozoa |
| 12 | viruses | 4 | Of amoebas, bacteria or viruses, the smallest |
| 13 | the shell | 4 | The development of this part of the egg contributed to the evolution of life on land |
| 14 | the esophagus | 4 | Peristaltic waves move down this tube that connects the pharynx & stomach |
| 15 | taxonomy | 4 | It's the branch of biology that classifies & names living organisms |
| 16 | pollination | 4 | Apple production depends on bees for this |
| 17 | oxygen | 4 | An aerobe can live only in an environment where this element is present in free form |
| 18 | melanin | 4 | Discounting Clairol, the color of human hair is mainly due to this dark pigment |
| 19 | cones | 4 | Seed plants are classified as angiosperms, producing fruit & flowers, or gymnosperms, producing these |
| 20 | cellulose | 4 | Protozoans living in a termite's gut break down this substance in the wood the termite eats |
| 21 | capillaries | 4 | They're your smallest blood transport tubes & in some the red cells have to go through single file |
| 22 | bacteria | 4 | The species "rhizobium" of these micro-organisms plays an important role in nitrogen fixation in plants |
| 23 | the yolk | 4 | As opposed to bird eggs, human eggs have very little of this material in which nutrients are stored |
| 24 | the lungs | 4 | Pulmonary is an adjective meaning "of this" organ |
| 25 | the host | 4 | The living organism from which a parasite gets its nourishment is called this |
| 26 | the liver | 3 | The prefix "hepat-", as in hepatitis, refers to this organ |
| 27 | the kidneys | 3 | These organs release an enzyme called renin that helps maintain blood pressure |
| 28 | the kidney | 3 | As its name indicates, an adrenal gland lies on this organ |
| 29 | symbiosis | 3 | It's an association of 2 different organisms living together for the advantage of both |
| 30 | spores | 3 | New molds form from these, not from seeds |
| 31 | regeneration | 3 | Exhibited by lower animals, it's the growth of new body parts to replace lost or broken ones |
| 32 | recessive | 3 | Mendel's laws of heredity deal with dominant traits & this type |
| 33 | plasma | 3 | Fluid that's left when you remove all the corpuscles from the blood |
| 34 | photosynthesis | 3 | In this process 8 photons of light break down 2 H2O molecules to yield an O2 molecule |
| 35 | leaves | 3 | A deciduous tree drops these in the autumn & produces new ones in the spring |
| 36 | insulin | 3 | Type 1 diabetes results when the body can't produce enough of this to process nutrients |
| 37 | green | 3 | Distinguishing color of chlorophyta, 1 of 3 major groups of algae |
| 38 | gills | 3 | They're the respiratory organs of a lobster |
| 39 | fungi | 3 | Mycology is the branch of biology that studies mushrooms, yeasts, molds & other types of these |
| 40 | fraternal twins | 3 | Dizygotic twins are more commonly known by this brotherly name |
| 41 | fat | 3 | People usually refer to adipose tissue as this |
| 42 | enzymes | 3 | Role of these complex proteins in living matter is to control rate at which energy is stored & released |
| 43 | clot | 3 | When blood does this, fibrinogen is converted to fibrin |
| 44 | cloning | 3 | 3 calves created this way made headlines back in 1988 |
| 45 | cilia | 3 | These threadlike projections on protozoans all beat in one direction to move it around |
| 46 | 2 | 3 | Total number of ventricles in a mammal's heart |
| 47 | the skin | 3 | For an adult elephant it can be up to 1 1/2" thick & weigh about a ton yet can be pierced by an insect |
| 48 | the nucleus | 3 | The 1st section of the cell to divide, it does it by mitosis, meiosis, or rarely, amitosis |
| 49 | temperature | 3 | Doctors sometimes induce hypothermia, which is this, to reduce metabolic activity |
| 50 | tail | 3 | A scorpion's stinger is located in this part of its body |