Cells and Neurons

Across

2. allows for quick focusing by moving the objective lens or stage up and down. It is used for initial focusing
3. neurons are motor neurons that carry neural impulses away from the central nervous system and towards muscles to cause movement
5. where the specimen is placed for observation
9. a level of organization in multicellular organisms that consists of a group of similar cells
10. release the neurotransmitters of the presynaptic cell into a gap called the synaptic cleft to be taken up by the dendrites of the next neuron
18. a thousandth of a metre 1/1000
19. usually the lens that is closest to the eye when someone looks through the device
20. a group of organs that work together to perform one or more functions
22. has different sized holes and is used to vary the intensity and size of the cone of light that is projected upward into the slide
24. an automatic response controlled solely by neural circuits in the spinal cord, often relating to posture or locomotion
25. the cell body is the neuron's core. It carries genetic information, maintains the neuron's structure, and provides energy to drive activities
26. are membrane-bound cell organelles that generate most of the chemical energy needed to power the cell's biochemical reactions
28. have many, smaller vacuoles and simply have a cell membrane, but no cell wall
29. a typically unicellular organism that lacks a nuclear membrane-enclosed nucleus
30. used to bring the specimen into sharp focus under low power
32. provides stability and support for the microscope when it is upright
35. the transportation system of the eukaryotic cell, and has many other important functions such as protein folding
37. the gaps in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses

Down

1. the highest level of organisation defined as a living thing that has an organized structure, can react to stimuli, reproduce, grow, adapt, and maintain homeostasis
4. is a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body
6. also called nerve fibre, portion of a neuron that carries nerve impulses away from the cell body. A neuron typically has one that connects it with other neurons or with muscle or gland cells
7. is a membrane-bound organelle that contains the cell's chromosomes
8. magnifies 40x, with total magnification 400x if the eyepiece lens is 10x power
11. a collection of tissues that specialized to perform a particular function
12. is a cellular particle made of RNA and protein that serves as the site for protein synthesis in the cell
13. a millionth of a metre 1/1000,000
14. contains a large, singular vacuole that is used for storage and maintaining the shape of the cell
15. are building blocks that make up all living things
16. processes and packages proteins and lipid molecules, especially proteins destined to be exported from the cell
17. a membrane-bound cell organelle that contains digestive enzymes
21. extend out-ward from the cell body and are specialized to receive chemical signals from the axon termini of other neurons
23. separates the interior of all cells from the outside environment (the extracellular space) which protects the cell from its environment
26. to be made up of many cells
27. neurons are sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain
31. an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances
33. to be made up of only one cell
34. a billionth of a metre 1/1000,000,000
36. designed to transmit light through a translucent object for viewing
38. organisms whose cells have a nucleus enclosed within a nuclear envelope