Across
- 2. - evidence that shows something to be true or correct
- 3. - parts of an experiment that can change and cause a change in the results
- 5. - electrical signals
- 9. - done automatically, without choice or control
- 12. - the young of an organism
- 17. - chemicals that help transmit nerve impulses
- 19. - the genes and traits that are passed along from parent to child
- 21. - two identical babies born to one mother at the same time; the result of one egg being fertilized and then dividing into two embryos
- 22. - also called atmospheric pressure; the weight of air pressing down on a particular part of Earth’s surface
- 24. - study or find out how different pieces of information relate to one another
- 25. - breeding two different types of plants with one another
- 26. - the qualities that make something different from others; traits
Down
- 1. - the qualities that make something different from others; characteristics
- 4. - human beings in the very early stages of development
- 6. - the long bundle of nerves inside the spinal column; part of the central nervous system
- 7. - the parts of a plant or animal that determine what traits will be passed on to the offspring
- 8. - fertilized; transferred grains of pollen from the male to the female parts of plants
- 10. - decisions reached by using careful thought and reasoning
- 11. - nerve cells
- 13. - special qualities of a substance or substances
- 14. - two non-identical babies born to one mother at the same time; the result of two eggs being fertilized by two sperm cells
- 15. - 0 K, or the temperature at which no heat energy is present; it exists only in theory and has never been reached; it is equal to -459.67°F
- 16. - the amount of heat energy stored inside a substance
- 18. - ways of taking measurements using a series or sequence of equal units
- 20. - brothers or sisters; people who share the same parents
- 23. - facts that can be used for calculating or reasoning