Download new zealand`s most comprehensive and up

NEW ZEALAND’S MOST COMPREHENSIVE AND UP-TO-DATE
LEVEL 2
BIOLOGY
REVISION GUIDE
ONLY
$12
INCLUDING GST
CONDITIONS APPLY
KEY NOTES WALK-THROUGHS HINTS TIPS 4 YEARS OF NCEA EXAMS 108 PAGES A4 FORMAT
2015 EDITIONS OUT NOW!
CHLOROPLASTS
•
Chloroplasts are found inside the cells of green plants and algae.
•
They are abundant in cells located near the top of the leaves in plants.
•
They contain the molecule chlorophyll that absorbs sunlight for photosynthesis.
•
Their structure maximises the rate at which photosynthesis can occur:
- Thin semi-permeable membrane allows light to penetrate.
- Thylakoids are flat and disc-shaped to increase the surface area for the
absorption of light.
- Grana are flat, compact piles of thylakoids.
- Grana are connected to each other by tubes called lamellae.
- Lamellae are suspended in a watery, transparent matrix, called the stroma.
Chloroplasts are located near the plasma membrane in cells so that the
distance raw materials (CO2 and H2O) have to diffuse is short.
PHOTOSYNTHESIS
The process of photosynthesis can be written as a simplified equation:
Carbon dioxide + Water
Sunlight
Chlorophyll
Glucose +
Oxygen
Every topic a student is expected to know
The actual process is complex and involves a number of reactions. These reactions can be divided into two main
is summarised,
helpful hints
included
steps - the light dependent
phase are
and the
light independent phase.
and key concepts
are reinforced. Worked
LIGHT-DEPENDENT PHASE
LIGHT-INDEPENDENT PHASE
examples
guide
and provide exemplars
• Occurs
in thylakoids.
• Occurs in stroma.
• Chlorophyll
for your
students.uses energy from light to split water • Enzymes join CO to a 5-carbon molecule to
2
(H2O).
•
Hydrogen (H) from this splitting is transferred
to NADP+ to make NADPH and an enzyme
produces ATP. Oxygen (O2) produced by the
splitting of water is released as a waste product.
LIGHT
produce a 6-carbon molecule with the aid of
NADPH and ATP.
•
Glucose is used to provide energy, changed
into other chemicals (cellulose, etc), or stored as
starch.
OXYGEN
CARBON DIOXIDE
ATP
rrier carrying hy
a
c
n
dro
ge
ge
dro
n
Hy
PHASE 1 - Photolysis
2H2O
O2 + 4H
PHASE 2 - Carbon fixation
Carbon dioxide and
hydrogen are used to
produce glucose
Energy from light is
used to split water.
ATP is also produced.
Hy
en
dro
rog
gen c
arrier with no hyd
ADP + P
STARCH, CELLULOSE
AND OTHER SUGARS
WATER
8
GLUCOSE
PHOTOCOPYING PROHIBITED
MUTATIONS
•
The sequence of bases on a strand of DNA contains the genetic code (genes and their alleles) for the
production of the proteins that, when assembled, make you.
•
In order to create a new gene or allele the base sequence on a section of DNA needs to change. When a
permanent change occurs in the base sequence of DNA, scientists call it a mutation.
G
A
G
C
T
G
T
G
A
G
G
G
A
G
C
G
G
T
G
A
G
G
C
T
C
G
A
C
A
C
T
C
C
C
T
C
G
C
C
A
C
T
C
C
The normal base sequence for a gene results in a protein
that causes a rat to be dark-coloured.
A point mutation in the gene for coat colour has resulted
in a different protein being produced. This has resulted in a
white-coloured rat.
•
Mutations can occur naturally during DNA replication or as a result of exposure to mutagens (substances that
cause mutations) such as some chemicals (e.g.those found in cigarettes and fatty foods), ultraviolet light
(from the sun), and radiation (from x-rays or radioactive materials, etc.).
•
Neutral or silent mutations have no observable effect on an organism.
•
Harmful mutations may affect the survival of the organism.
•
Beneficial mutations may give the organism a survival advantage over other members of its species, and it
may live on in conditions where others die (e.g. there are insects that, due to a mutation, are resistant to most
common insecticides).
•
If a mutation occurs in a body cell (somatic cell) it cannot be passed on to the next generation. Only when
a mutation occurs in reproductive cells (gametic cells) can it be passed on to offspring.
QUESTION ONE: MUTATION
NZPQA
New Zealand Pretend Qualifications Authority
Discuss how mutation can lead to changes of alleles in the offspring of an organism, and the effect this can
have over time.
In your response you should include:
• Why only some mutations are inherited.
• The significance of changes over time.
A mutation is a permanent change in the base sequence of DNA. Somatic mutations
are alterations in DNA that occur after conception and occur in any of the cells of
the body except the gametes (sperm and egg). Therefore, somatic mutations are not
passed on to the offspring.
Gametic mutations are a heritable change in the DNA that occurred in a gamete – a
cell destined to become an egg or sperm. When transmitted to the offspring, a gametic
mutation is incorporated into every cell of their body.
Gametic mutations can lead to the formation of new alleles, changes in the allele
frequency and therefore, produce variation.
Changes in allele frequency over time may be of benefit if environmental factors
change making the allele more favourable increasing its frequency or less favourable
decreasing its frequency. Neutral mutations may become positive or negative as the
conditions of the environment change over time.
PHOTOCOPYING PROHIBITED
43
Walk-through - Cell Structures
QUESTION ONE: MITOCHONDRIA AND CHLOROPLASTS
(a)
Walk-through
Mitochondria and chloroplasts are both found in plant cells.
•
Describe the main structural features of mitochondria AND chloroplasts.
•
Outline the function of both organelles.
•
You may use labelled diagrams in your answer.
Describe the features
of
mitochondria.
Include terms such as
folded membrane,
matrix,
chemical
reactions,
surface
area and cristae.
Describe the function
of
mitochondria.
Use terms such as
respiration,
break
down, energy (ATP)
and transport.
NCEA-style questions are included, with
walk-throughs, hints and tips designed
to help students write complete and
extended answers.
Describe the features
of
chloroplasts.
Include terms such
as
chlorophyll,
inner
and
outer
membrane,
grana
(or
granum)
thylakoids, stroma).
Discuss the function
of
chloroplasts.
Include terms such
as
chemicals,
photosynthesis,
sunlight.
Draw
a
labelled
diagram of both a
mitochondrion and
chloroplast in the
space provided.
12
PHOTOCOPYING PROHIBITED
NCEA Exam Questions - Variation
QUESTION ONE: NEW ALLELES (2014)
Pumpkins can grow in the wild. Wild pumpkins are usually round and have seeds in the centre. With the seeds
being in the centre, when animals take a bite there is a high chance of seeds being eaten and then distributed.
Mutations can occasionally cause pear-shaped pumpkins to form. Pear-shaped pumpkins have seeds at only
one end.
(a)
Definetheterm‘mutation’.
(b)
Gametic mutation leads to pear-shaped pumpkins.
Explain the process of gametic mutation including what it is, and where it occurs.
Four years of previous NCEA exam questions
are provided. A separate answers section
allows students to improve and gauge their
chances of success.
QUESTION TWO: VARIATION (2013)
Sources of variation in a gene pool result from the biological processes such as independent assortment and
mutation.
Discuss how independent assortment and mutation lead to variation within a gene pool.
In your answer:
•
Describe independent assortment and mutation.
•
Explain why mutations are the major source of new alleles in a population AND why independent assortment
does not introduce new alleles into a population.
•
Compare and contrast how independent assortment and mutation produce variation within an
organism.
48
PHOTOCOPYING PROHIBITED
THE SCIPAD RANGE
JUNIOR SCIENCE
LEVEL 1 SCIENCE
LEVEL 1 SCIENCE MICRO
LEVEL 1 REVISION
256 Pages - $18.00
256 Pages - $20.00
88 - 96 Pages - $8.50
108 Pages - $12.00
LEVEL 1 CHEMISTRY
LEVEL 1 PHYSICS
LEVEL 1 BIOLOGY
88 - 96 Pages - $8.50
72 - 96 Pages - $8.50
88 - 96 Pages - $8.50
LEVEL 2 CHEMISTRY
LEVEL 2 BIOLOGY
LEVEL 2 PHYSICS
External Standards 304 Pages - $20.00
Internal Standards 104 Pages - $5.00
Revision Guide 108 Pages
- $12.00
External Standards 240 Pages - $20.00
Internal Standards 96 Pages - $5.00
Revision Guide 108 Pages - $12.00
External Standards 352 Pages - $20.00
Internal Standards 96 Pages - $5.00
Revision Guide 108 Pages - $12.00
VIEW EVERY PAGE ONLINE