pages 24-29 theory v law Flashcards
(24 cards)
Do prokaryotic cells have a nucleus?
no
Are prokariotic or Eukariotic cells multicellular?
Eukaryotic
Where whould you find the DNA in Prokaryotic and Eukayotic cells
Prokaryotic- in cytoplasm
Eukaryotic- in nucleus
Do both cells have ribosomes?
yes
How do prokariotic and eukariotic cells reproduce
prokariotic- Asexual
Eukariotic- sexual
Which type of cell has membrane bound organelles?
Eukariotic
Do both cell types have ribosomes?
Yes
Are prokariotic cells unicellular
yes
Are eukariotic cells unicellular
no multicellular
Do both cells contain DNA
yes
What is mitosis
a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
What is meiosis
Meiosis is a special type of cell division of germ cells in sexually-reproducing organisms used to produce the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome.
What is a Theory
explains why something happens
logical and supported by empirical evidence
do not become laws
can be adjusted
an educated guess
What is a law
answers what happens
predicted outcomes supported by large amounts of empirical evidence
discribes a single pattern or event in nature
can be rivised
What are the 3 parts of the cell theory
all organisms are made of cells
all cells are produced by other living cells
the cell is the most basic unit of life
how did robert hooke contribute to the cell theory
used compound microscope to observe corks
discovered cells in 1665
small hollow compartments that looked like “cells”
named cells
What did Anton Van Leewenhoek contributr to the cell theory
became first scientist to reffer to living cells
observed an abundant number of single-celled organisms which he called animacules swimming in a drop of pond water
What did matthias schleiden contribute to the cell theory
From investigating and experimenting with plants, projected plant parts are made of cells!
Theodor schwann
From investigating and experimenting with plant & animal cells, Schwann was able to determine that all animals are made of cells!
rudolf virchow
Based on his investigations and experiments, he stated that all cells come from preexisting cells, which is the 2nd part of the cell theory: all existing cells are produced by other living cells!
Disecting Microscope
used to get a close image when examining or disecting biological specimines
living and nonliving
light illumination
low magnification
3d image
Compound microscope
gets down to cellular leval
living and nonliving
40 to 1000 mag
light illumination
2d image
- The first lens, Objective Lens, is located just above the specimen
- This lens enlarges the image of the specimen
- The second lens, Ocular Lens, magnifies this image further
most living cells are nearly transparent
•Chemical stains or dyes are used to help make cells and their parts visible
Scanning electron microscope
scanned computer generated images
black and white
high detail and resolution images
500000 mag
nonliving specimines
3d image
high mad
electron illumination
- Pencil like beam of electrons is scanned over the surface of a specimen
- Image is formed at the specimen’s surface
- Samples do not have to be cut into thin slices to be seen
transmission electron microscope
black and white
transfers to computer
high mag and resolution
10 mill mag
dead objects
- Transmission means “the process of sending”
- Explore cell structures and large protein molecules
- Beam of electrons can only pass-through thin samples
- Cells and tissues must be cut into extremely thin slices before examination
- Why images often appear flat and two dimensional
