3 eso urbanisation, melbourne de I.E.S Velázquez. by Nadia Elkin
UNIT 1: SCIENTIFIC NOTATION:Maths and Science.
HOW BIG IS A HUMAN CELL?
How big is a human cell?
A human is an assortment of 1013-1014
cells, plus an enormous complement of 1014 allied microbes. The
identities of these 1013 cells are shared among more than 200
different cell types which perform an amazing variety of different functions.
One of the ways we can recognize these diverse cell types is on the basis of
their very different shapes. For example, the leukocytes of the immune system
are approximately spherical in shape while adherent tissue cells on a
microscope look like a fried egg with the nucleus analogous to the yolk. By way
of contrast, the neurons connecting our brains to our legs can reach lengths of
over a meter but with a width of only about 10 µm.
- How many cells
constitute the human body? Write the number in scientific and decimal notation.
-
What is the size of a neuron? Express its width in meters
New
vocabulary:
Assortment:
conjunto
Allied:
aliado
Share:
compartir
Among:
entre
Staggering:
sorprendente
Yolk:
yema
Some cells are visible to the unaided
eye
The
smallest objects that the unaided human eye can see are about 0.1 mm long. That
means that under the right conditions, you might be able to see an
ameobaproteus, a human egg, and a paramecium without using magnification. A
magnifying glass can help you to see them more clearly, but they will still
look tiny.
Smaller
cells are easily visible under a light microscope. It's even possible to make
out structures within the cell, such as the nucleus, mitochondria and
chloroplasts. Light microscopes use a system of lenses to magnify an image. The
most powerful light microscopes can resolve bacteria but not viruses.
To
see anything smaller than 500 nm, you will need an electron microscope.
Look at the following list:
- 0,1 nm diameter of a hydrogen atom
- 7 nm thickness cell membranes
- 20 nm ribosome
- 50 nm Nuclear pore
- 200 nm Centriole
- 200 nm Lysosomes
- 3 µm Mitochondrion
- 5 µm length of chloroplast
- 6 µm the Nucleus
- 9 µm human red blood cell
1. Which is the smallest organelle? Write its size in
meters using scientific and decimal notation.
2. Which is the biggest organelle in human cells? Write its size in meters using scientific and decimal notation.
3. What information is shown about the membrane? Express the information in meters using both notations.
New vocabulary:
unaided: sin ayuda
thickness: grosor
Watch the following video:
A mag created with Madmagz.
UNIT 3:GEOMETRY IN THE ALCÁZAR OF SEVILLE. Maths and English
3º ESO students learnt Geometry in the Alcázar. They also were excellent tour guides.
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