Class X Science

1
Class XScience
2
I.MEASUREMENTS VERNIER CALIPER AND SCREW GAUGE

• PLAY THE VIDEO no. 1.

3
SCREW GAUGEPlay the video no. 2
4
measurement of length
micrometer screw gauge
Micrometers measure small diameters or
thicknesses.
accuracy 0.01 mm / 0.001 cm
5
measurement of length
micrometer screw gauge
reading on sleeve 4.5 mm reading on thimble
0.12 mm actual reading of object 4.5
0.12 4.62 mm
6
measurement of length
micrometer screw gauge
When the anvil and spindle of the micrometer
touch each other, the scales should read zero.
If not, there is a zero error in the
micrometer.
7
measurement of length
micrometer screw gauge
If the anvil and spindle touch each other, but
the scales do not read zero as shown below, the
zero error is positive.
supposing observed reading is 2.37 mm, then
corrected reading observed reading zero
error 2.37 (0.02)
2.35 mm
8
measurement of length
micrometer screw gauge
If the anvil and spindle touch each other, but
the scales do not read zero as shown below, the
zero error is negative.
3 divisions
supposing observed reading is 2.87 mm, then
corrected reading observed reading zero
error 2.87 (-0.03)
2.90 mm
9
measurement of time
time
Time can be measured by using the following

• clocks

• analogue stopwatch

• digital stopwatch

All timing devices make use of some regular
process.
10
measurement of time
the period of a simple pendulum
Time can also be measured by using the following
simple pendulum.
pendulum bob tied to one end of a thread

• oscillations are regularly repeating motions
• the period is time in which 1 oscillation occurs

B
A
O
11
measurement of time
watch
wrist watch
12
II.Newtons Laws of Motion

• I. Law of Inertia
• II. Fma
• III. Action-Reaction

13
2nd Law
F m x a
14
2nd Law

• The net force of an object is equal to the
  product of its mass and acceleration, or Fma.

15
2nd Law

• When mass is in kilograms and acceleration is in
  m/s/s, the unit of force is in newtons (N).
• One newton is equal to the force required to
  accelerate one kilogram of mass at one
  meter/second/second.

16
(No Transcript)
17
(No Transcript)
18
3rd Law

• For every action, there is an equal and opposite
  reaction.

19
3rd Law
Flying gracefully through the air, birds depend
on Newtons third law of motion. As the birds
push down on the air with their wings, the air
pushes their wings up and gives them lift.
20
III.Temperature is a measure of

• The total amount of energy in an object
• The total amount of thermal energy in an object
• How much heat something gives off
• How fast the molecules in an object are moving

21
Heat is

• Energy given off or absorbed by an object
• A measure of the motion of the molecules in an
  object
• The total amount of molecular energy in an object

22
How do we measure temperature?

• Think about using a thermometer

23
How does the thermometer know how hot the
substance is?
24
Temperature is a measure of

• The total amount of energy in an object
• The total amount of thermal energy in an object
• How much heat something gives off
• How fast the molecules in an object are moving

25
Heat is

• Energy given off or absorbed by an object
• A measure of the motion of the molecules in an
  object
• The total amount of molecular energy in an object

26
Put this bottle with the coin on top in the
freezer for a half hour.
What happens when you take it out and put it on a
table at room temperature?
27
Gases do not necessarily expand when you heat them
Gases do not necessarily contract when you cool
them
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
The heat balance of the Earth
33
IV. Sound
34
The Ear

• Sound is carried to our ears through vibrating
  air molecules.
• Our ears take in sound waves turn them into
  signals that go to our brains.
• Sound waves move through 3 parts of the ear
  outer ear, middle ear, inner ear.

Middle Ear
35
Sonar

• An instrument that uses reflected sound waves to
  find underwater objects
• For example,

Humans use sonar to locate or map objects
Animals use sonar or echo location to find their
prey these sounds have such a high pitch or
frequency that the human ear cannot hear
36
Sound and Instruments

• Instruments can be played at different pitches by
  changing lengths of different parts.
• For example,
• Another way to make different pitches is to
  change the thickness of the material that
  vibrates.
• For example,

A trombones mute absorbs some of the sound waves
produced, thus producing a softer note when
played.
37
Play the video No.3
38
V.Optics

• Mirrors and Lenses

39
Curved mirrors

• What if the mirror isnt flat?
• light still follows the same rules, with local
  surface normal
• Parabolic mirrors have exact focus
• used in telescopes, backyard satellite dishes,
  etc.
• also forms virtual image

40
For a real object between f and the mirror, a
virtual image is formed behind the mirror. The
image is upright and larger than the object.
For a real object between f and the mirror, a
virtual image is formed behind the mirror. The
position of the image is found by tracing the
reflected rays back behind the mirror to where
they meet. The image is upright and larger than
the object.
41

For a real object between f and the mirror, a
virtual image is formed behind the mirror. The
position of the image is found by tracing the
reflected rays back behind the mirror to where
they meet. The image is upright and larger than
the object.
For a real object close to the mirror but outside
of the center of curvature, the real image is
formed between C and f. The image is inverted and
smaller than the object.
For a real object between C and f, a real image
is formed outside of C. The image is inverted and
larger than the object.
For a real object between C and f, a real image
is formed outside of C. The image is inverted and
larger than the object.
42

For a real object between f and the mirror, a
virtual image is formed behind the mirror. The
position of the image is found by tracing the
reflected rays back behind the mirror to where
they meet. The image is upright and larger than
the object.
For a real object close to the mirror but outside
of the center of curvature, the real image is
formed between C and f. The image is inverted and
smaller than the object.
For a real object between C and f, a real image
is formed outside of C. The image is inverted and
larger than the object.
For a real object at C, the real image is formed
at C. The image is inverted and the same size as
the object.

For a real object at C, the real image is formed
at C. The image is inverted and the same size as
the object.
43

For a real object between f and the mirror, a
virtual image is formed behind the mirror. The
position of the image is found by tracing the
reflected rays back behind the mirror to where
they meet. The image is upright and larger than
the object.
For a real object close to the mirror but outside
of the center of curvature, the real image is
formed between C and f. The image is inverted and
smaller than the object.
For a real object close to the mirror but outside
of the center of curvature, the real image is
formed between C and f. The image is inverted and
smaller than the object.
44

For a real object at f, no image is formed. The
reflected rays are parallel and never
converge.
What size image is formed if the real object is
placed at the focal point f?
For a real object at f, no image is formed. The
reflected rays are parallel and never converge.
45
Convex Mirrors

• Curves outward
• Reduces images
• Virtual images
• Use Rear view mirrors, store security

CAUTION! Objects are closer than they appear!
46
Refraction

• Light also goes through some things
• glass, water, eyeball, air

47
Convex Lenses

• Thicker in the center than edges.
• Lens that converges (brings together) light rays.
  
• Forms real images and virtual images depending on
  position of the object

The Magnifier
48
Concave Lenses

• Lenses that are thicker at the edges and thinner
  in the center.
• Diverges light rays
• All images areerect and reduced.

The De-Magnifier
49
How You See

• Near Sighted Eyeball is too long and image
  focuses in front of the retina
• Near Sightedness Concave lenses expand focal
  length
• Far Sighted Eyeball is too short so image is
  focused behind the retina.
• Far Sightedness Convex lense shortens the focal
  length.

50
VI. CHEMICAL BONDSPLAY THE VIDEO NO. 5
51
VII.CHEMICAL BONDSPLAY THE VIDEO NO. 6
52
VIII. Basic Mendelian Principles

• Mendels big ideas
• --Particulate inheritance the determinants
  of inherited traits are discrete units that are
  passed between generations unaltered, not blended
  together.

53
Experimental Organism

• Mendel worked with peas.
• --The male gametepollen grain.
• --The female gameteovule.
• Pea plants have both sexes on the same plant, and
  they can be self-pollinated pollen from one
  plant is used to fertilize ovules from the same
  plant.

54
Mendel's Traits
55
Monohybrid Cross

• when plants with different traits are crossed.
• Purple flowers vs. white flowers. The original
  parental lines are pure-breeding.

56
First Cross

• True-breeding purple x true-breeding white. All
  offspring are purple. The parent lines are the P
  generation the offspring are the F1 (first
  filial) generation.
• All the F1's are purple regardless of which
  parent (father or mother) was purple and which
  was white.

57
Selfing the F1

• Self-pollinate the F1 plants to get the F2
  (second filial) generation.
• The F2 appear in a ratio of 3/4 purple to 1/4
  white.

58
Selfing the F2

• Each F2 plant is selfed to produce a group of F3
  offspring.
• The F3 offspring of the white F2's are all
  white-true-breeding.
• Some of the F2 purples have all purple F3 -true
  breeding.
• Other F2 purples give purple and white F3's in a
  ratio of 3/4 purple to 1/4 white. This is the
  same behavior as the F1's had.

59
F2 Behavior

• The purple F2 plants come in 2 types some are
  true breeding and only give purple offspring.
  Others are hybrids and give 3/4 purple 1/4
  white offspring. They can be distinguished by
  the offspring they produce, but not by their
  physical appearance.

60
F2

• In summary, 1/4 of the F2 genotypes are PP, 1/2
  are Pp, and 1/4 are pp.
• Since P (purple) is dominant, both PP and Pp
  plants are purple. Thus, 3/4 of the phenotypes
  are purple, and 1/4 are white.
• Mendel found that this rule worked for all 7 of
  his traits, to within what he considered
  reasonable accuracy.

61
Mendel Monohybrid Results
62
Law of Segregation

• Mendel's first law of genetics
• The two members of a gene pair segregate randomly
  and equally into the gametes, which then combine
  at random to form the next generation.

63
Dihybrid Cross

• A dihybrid cross examines 2 different genes. We
  will use yellow vs. green pods, and round vs.
  wrinkled seeds.
• Yellow (Y) is dominant to green (y).
• Round (R) is dominant to wrinkled (r).
• Initial cross YY rr x yy RR (yellow wrinkled x
  green round). The YY rr plant makes Yr gametes (
  one copy of each gene) and the yy RR plant makes
  yR gametes.
• These combine to make F1 plants that are Yy Rr,
  yellow round. Note that neither parent has this
  phenotype.

64
F1 -gt F2 Dihybrid

• When the Yy Rr plant is mated, it makes 4 kinds
  of gamete. Each gamete gets 1 copy of each gene,
  so 1/2 are Y and 1/2 are y. Independently, 1/2
  are R and 1/2 are r. Thus, 1/4 of the gametes
  are YR, 1/4 are Yr, 1/4 are yR, and 1/4 are yr.
  This happens for both male and female gametes.
• The gametes combine randomly. The combinations
  are shown in a 16 cell Punnett square.

65
F2 dihybrid results are the combination of 2
monohybrid crosses

• If you just look at the individual genes
  separately, you find the same 3/4 1/4 ratio
  seen in the monohybrid cross.
• Thus, 9/16 are yellow round and 3/16 are yellow
  wrinkled. This adds up to 12/16 3/4 yellow.
  And, 3/16 are green round and 1/16 are green
  wrinkled, which adds up to 4/16 1/4 green.
• Same is true for round vs. wrinkled.

66
Law of Independent Assortment

• Mendel's second law.
• For unlinked genes, the alleles from each gene
  segregate into the gametes independently of one
  another.
• Some genes are linked, which means that they
  don't segregate independently of each other and
  thus don't give the 9331 ratio of F2 offspring.

67
REAL TIME(videos click from video file 1, 2)

• CELL DIVISION OCCURS IN VERY FEW SECONDS AS YOU
  SEE IN THE VISUAL. DONT MISS THE DIFFERENT
  STAGES OF MITOSIS THAT OCCURS IN ROOT TIP OF
  ONION, VERY FASTLY.

68
XI. MEIOSIS

• Meiosis reduces the number of chromosomes by
  half.
• Daughter cells differ from parent, and each
  other.
• Meiosis involves two divisions, Mitosis only one.
• Meiosis I involves
• Synapsis homologous chromosomes pair up.
  Chiasmata form (crossing over of non-sister
  chromatids).
• In Metaphase I, homologous pairs line up at
  metaphase plate.
• In Anaphase I, sister chromatids do NOT separate.
• Overall, separation of homologous pairs of
  chromosomes, rather than sister chromatids of
  individual chromosome.

69
(No Transcript)
70
(No Transcript)
71
(No Transcript)
72
(No Transcript)
73
Meiosis 1

• First division of meiosis
• Prophase 1 Each chromosome duplicates and
  remains closely associated. These are called
  sister chromatids. Crossing-over can occur during
  the latter part of this stage.
• Metaphase 1 Homologous chromosomes align at the
  equatorial plate.
• Anaphase 1 Homologous pairs separate with sister
  chromatids remaining together.
• Telophase 1 Two daughter cells are formed with
  each daughter containing only one chromosome of
  the homologous pair.

74
Meiosis II

• Second division of meiosis Gamete formation
• Prophase 2 DNA does not replicate.
• Metaphase 2 Chromosomes align at the equatorial
  plate.
• Anaphase 2 Centromeres divide and sister
  chromatids migrate separately to each pole.
• Telophase 2 Cell division is complete. Four
  haploid daughter cells are obtained.