aerobic afterbirth algae alimentary canal amber ameba amino acid

amoeba anaconda anaerobic androgynous antibody antigen antitoxin

appendage arm armour asexual assimilation atrophy aviary

bacteria bacteriology barnacle bile binocular vision bio-

biochemistry biodegradable biodiversity biological clock biology biomass

biome biosphere blind brain breathe breed(v) breed(n) breeding bristle

bulb capsule carbohydrate carbon dioxide carnivore cell cellular

cellulose central nervous system cervical cholesterol chromosome

circulation circulatory class clone cold-blooded conceive conch

connective tissue copulate coral reef cornea coronary corpuscle cortex

cortisone cowrie crab crawfish crayfish creature cross crossbreed

culture decay(v) decay(n) decompose defecate denizen dextrose

diaphragm digest digestion digestive DNA dorsal dry rot duct

dwarf(n) dwarf(a) ecological ecology ecosystem egg ejaculate embryo

embryonic enzyme epidermis evolution evolutionary excrement

excrescence excrete excretion exhale extinction faeces family fang

fat fatty acid fauna feces feed female(a) female(n) ferment(v)

ferment(n) fertile fertility fertilize fission flank flatulence flesh fleshy

flightless flora foetal foetus foliage fossil freak freshwater fructose

gamete ganglion gene gene pool genera genetic genetic code

genetic engineering genetic fingerprinting genetics genome genus

gestation gland glandular glucose gluten gonad grass snake grow

growth habitat haemoglobin hearing heart hemisphere herbivore

hereditary heredity hermaphrodite hibernate histamine homing hormone

host impregnate impulse incubate indigenous infected infertile infest

ingest inhale inseminate insensate insulin integument intercourse

interferon intestine invertebrate involuntary iris jaw jelly kidney krill

lactate lactation lactic acid leech leg lesser lichen life life cycle

life form ligament limb limpet lipid liver living fossil locomotion

lymph lymph node male(a) male(n) mammal mandible mate(n)

mate(v) membrane metabolism metabolize metamorphosis microbe

microbiology microorganism microscopic migrate migratory miscarriage

molar morphology motor mould mouth mucous membrane mucus

muscle muscular mutant mutate mutation natural history natural

selection nature neck nectar nerve nervous nervous system neural

neuro- neurology node nose nostril nucleic acid nucleus nutrient

nutriment oesophagus oestrogen olfactory optic organ organic organic

chemistry organism orifice ossify osteo- outgrowth ovary overwinter

oviduct oviparous ovulate ovum parasite pathogen pedigree pelvic

pelvis penile penis pepsin period perspiration perspire photosynthesis

phylum pigment pigmentation plankton plasma pollinate postnatal

pregnancy pregnant premature prenatal product proliferation propagate

protein protoplasm protozoan puberty pulmonary pulp pulsation putrefy

putrid red blood cell regurgitate renal reproduce reproduction

reproductive respiration respiratory respire retina root rot(v) rot(n) ruff

sac saliva salivary gland salivate saltwater scale scallop scaly

sebaceous secrete secretion semen sense organ sensory serum sex(n)

sex(v) sexless sexual intercourse sheath shell sibling skeletal skeleton

skin skull spasm spasmodic species specimen sperm spiderweb spinal

cord spine spineless starch stem cell stimulate stimulus strain

subject subspecies sucker sucrose sweat(v) sweat(n) sweat gland

symbiosis systemic tail taxonomy teeth testosterone test-tube baby

tissue trachea tube urethra uric urinate urine variety vector vein

venom venomous ventricle vertebra vertebrate vivisection warm-blooded

wean wildlife windpipe yolk