Transcript Test Prep Middle Grades

38. Spectrometer
A spectrometer is an optical instrument used to measure properties of
light over a specific portion of the electromagnetic spectrum. In
astronomy, spectrometers have been used in star spectral classification.
39. Doppler Shift
A spectrometer can tell us if a star is moving toward or away
from the Earth by indicating a changes in spectral
wavelength.
Shorter wavelengths indicate a star is moving toward us.
Longer wavelengths indicate a star is moving away from us.
40. Space Rocks
Asteroid - a diverse group of small
celestial bodies that drift in the solar
system in orbit around the Sun
Comet - a small body in the solar
system that orbits the Sun exhibits a
coma and/or a tail — both primarily
from the effects of solar radiation
upon the comet's nucleus
Meteor / Meteorite - a meteor is the
visible path of a meteoroid that enters
the atmosphere; meteorites are
meteoroids that make it to the
Earth’s surface without burning up
41. More on Space
Galaxy - a huge gravitationally bound
system of stars, interstellar gas and
dust, plasma, and (possibly) unseen
dark matter The Milky Way
Constellation - a group of stars visibly
related to each other in a particular
configuration or pattern
The Big Dipper
Nebula - a cloud of interstellar gas
and dust that, in theory, may
condense to form a planetary system
The Horsehead Nebula
41. Even More on Space
Asteroid Belt - An asteroid is a chunk
of rock and metal floating in space.
It is leftover from when the Sun and
planets formed. The asteroid belt is
located between the planet Mars and
Jupiter. There is where most of the
asteroids are in the solar system.
Kuiper Belt - The Kuiper belt is made
up of objects that are composed
largely of frozen methane, ammonia,
and water. Pluto is found in the
Kuiper belt along with thousands of
other Kuiper belt objects.
42. Hypertonic v. Hypotonic
A hypertonic solution has a higher
concentration of solutes than that in a
cell. This solution has more solute
particles and, therefore, relatively less
water so water flows out.
A hypotonic solution has a lower
concentration compared to the cell so
water flows in. Cells can burst.
An isotonic solution has equal
concentration of solutes so water moves
equally into and out of cells.
43. Prokaryotes
44. Cell Organelles (Page 1 of 2)
Lysosomes: contain enzymes necessary for
intracellular digestion; in white blood cells that
destroy bacteria, lysosome contents kill and
digest the bacteria
Endoplasmic reticula: a structure that is
responsible for protein translation, folding, and
transport of proteins
Nuclei: organelles that communicate with the
rest of the cell via numerous nuclear pores; within
the nucleus is the DNA responsible for providing
each cell with its unique characteristics
Mitochondria: provide the energy a cell needs to
move, divide, produce secretory products, and
contract; they are the power centers of a cell
44. Cell Organelles (Page 2 of 2)
Ribosome: an organelle
that assembles proteins
Centriole: organelles
that aid in cell division
Golgi apparatus: a structure that is mainly
responsible for packaging macromolecules
for transport elsewhere in the cell
Vesicle: stores, transports,
or digests cellular products
and wastes
Vacuole: removes unwanted debris;
isolates materials that might be harmful
to the cell; maintains internal turgor
pressure and pH
45. Nondisjunction
Nondisjunction is the failure of
chromosome pairs to separate
properly. The result of this error is
a cell with an imbalance of
chromosomes.
When a chromosome is lost, it is
called a monosomy.
When a chromosome is gained, it
is called a trisomy.
Trisomy 21 is the cause of
approximately 95% of observed
Down syndromes, with 88%
coming from nondisjunction in the
maternal gamete and 8% coming
from nondisjunction in the
paternal gamete.
46. Inheritance Ratios (Page 1 of 2)
Genotype: the "internally coded, inheritable information"
carried by all living organisms
Phenotype: the "outward, physical manifestation" of an
organism
Complete Dominance:
- characteristics of some genes
completely dominate others
Ex. tall (Tt) plants with tall (T) and
short (t) genes producing tall (TT, Tt)
and short (tt)
Incomplete Dominance:
- no dominance of one gene
type over another
Ex. pink (wr) flowers with white (w)
and red (r) genes producing white
(ww), red (rr), and pink (wr)
Punnett Squares
T
t
T
TT
Tt
t
Tt
tt
w
r
w
r
ww wr
wr rr
Genotype Ratio:
1TT:2Tt:1tt
Or 1:2:1
Phenotype Ratio:
3T:1t
Or 3:1
Genotype Ratio:
1ww:2wr:1rr
Or 1:2:1
Phenotype Ratio:
1ww:2wr:1rr
Or 1:2:1
46. Inheritance Ratios (Page 2 of 2)
Monohybrid Cross: a cross of an organism dealing with
only one characteristic
Dihybrid Cross: a cross of an organism dealing with two
characteristics
TR
Tr
tR
tr
TR
TTRR
TTRr
TtRR
TtRr
Tr
TTRr
TTrr
TtRr
Ttrr
tR
TtRR
TtRr
ttRR
ttRr
tr
TtRr
Ttrr
ttRr
ttrr
Phenotype Ratio:
9TR:3Tr:3tR:1tr
Or 9:3:3:1
Genotype Ratio:
1TTRR:1TTRr:2TtRr:2TtRR:4TtRr:2Ttrr:2ttRr:1ttRR:1ttrr
Or 1:1:2:2:4:2:2:1:1
47. Sickle-Cell Disease
Sickle-Cell Disease: a genetic disease in which people inherit
two copies of the sickle cell gene, one from each parent
Note: In the sample above, “S” is equivalent
to “a” in the Test Prep Guide.
48. Protein Synthesis
Protein Synthesis: the process in which cells build proteins
(a) DNA info is transcribed to RNA.
(b) This RNA is then subject to posttranscription, resulting in a mature mRNA
that is then transported out of the nucleus
and into the cytoplasm.
(c) Here mRNA goes through translation into
a protein by ribosomes that match the threebase codons of the mRNA to the three-base
anti-codons of the appropriate transfer RNA
(tRNA).
(d) Newly synthesized proteins (black) often
go through post-translation, such as by
binding to an effector molecule (orange), to
become fully active.
49. Determining Phylum
Porifera: sponges
Annelida: segmented worms
Platyhelminthes: flatworms
Nematoda: roundworms
50. Protozoan Classification
Protozoans are unicellular organisms which are classified
into five phylums according to differences in movement
Five phylums of Protozoans:
1. Ciliata - the phylum in which creatures are
covered with short hair-like structures called cilia
2. Mastigophora - the phylum having
characteristic whiplike structures called flagella
3. Sarcodina - free-living protozoans having
pseudopods
4. Cnidospora - the phylum characterized by
walled spores, which have hollow polar filaments
5. Sporozoa - parasites that move passively and
anchor themselves firmly inside the organism they
invade
51. Plant v. Animal Cells
Plant Cell
Animal Cell
52. Root Endodermis
Endodermis: In plants, it is a thin
layer of cells found in roots, just
outside the vascular cylinder. It
regulates the flow of water and
minerals. Endodermis is tightly
packed together and contains a
waxy substance which prevents
water from flowing back into the
soil. Water is forced toward the
center of the root, into the xylem,
where it is then transported into
the rest of the plant.