Download Discuss how living things need to adapt to changing

Year 11 Science
DEMONSTRATE UNDERSTANDING OF GENETIC VARIATION
Achievement Standard:
Science 1.9
ACHIEVEMENT OBJECTIVES: Living World
Evolution
 Explore patterns in the inheritance of genetically controlled characteristics.
 Explain the importance of variation within a changing environment.
TEXTS:
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ESA revision Guide (ESA)
New Directions in Science (ND)
Content
Cells and Cell structure (plant and animal).
This only needs the barest coverage as an
introduction. Emphasise that all living things are
made of cells.
 Define a cell and the role of the cell membrane,
cytoplasm, nucleus, mitochondria, cell wall
(plant), vacuole and chloroplast.
 Compare animal and plant cells.
 Emphasise the importance of the nucleus.
 Practical: Lock at onion cells (use iodine to stain)
or cheek cells (use methylene blue to stain).
Chromosome, Gene, DNA
 Show ‘How genes work’ video.
 Define chromosome, gene, DNA, nucleotide,
alleles, DNA and their relationship to each other.
 Structure of DNA, covering phosphate, sugar
(ribose) backbone and base rungs. (Adenine,
Guanine, Cytosine and Thymine)
Human karyotype
 Construct a human karyotype and identify sex
from the karyotype.
Reference
ND p136-137 Ex 7F
‘How genes work’ video.
Hmwk: ESA p67 Ex6A
Karyotype to cut and paste.
4 weeks
Year 11 Science
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 Two copies of every chromosome.
Cell Division: Mitosis
 Purpose is for growth and repair and to produce
identical copies of the original cell.
 Describe effect on chromosome number (names
of stages not required) and define homologous
pairs.
 Discuss role of DNA in carrying instructions to
next generation of cells so that daughter cells
are identical to the parent cell.
 Sequence and label mitosis diagram (mixed up
photos and diagrams in folder).
 Web task:
http://www.biologycorner.com/worksheets/mito
meo.html
Cell Division: Meiosis
 Purpose is to produce sex cells with half the
usual chromosome number.
 Mention the mixing of genes (crossing over), but
there is no need to go into great detail.
 Discuss role of DNA from both parents in
carrying instructions to next generation of
animal/plant and how this results in genetic
variation.
 Comparison between meiosis and mitosis.
 Discuss role that meiosis and sexual
reproduction play in genetic variation in a
population.
ND p138-139 Ex 7G
 Mitosis videos:
http://videos.howstuffworks.com/search.php?terms=mitosis&me
dia=video
 http://www.youtube.com/watch?v=AhgRhXl7w_g


This website lists a number of other sites with good animations
and photographs of cells undergoing cell division. Especially
good are the links "Animal Cell Mitosis", “Mitosis in Onion Root
Tips" and "PBS: How Cells Divide: Mitosis vs.
Meiosis".http://www.emints.org/ethemes/resources/S00000759.
shtml
Hmwk: ESA p71 Ex6B
ND p140-141 Ex 7H
 ACTIVITY: Cut and paste/rearrange meiosis diagram.
Website:
http://www.emints.org/ethemes/resources/S00000759.shtml
 Family patterns’ video
Hmwk: ESA p74
8
Sexual vs Asexual reproduction
ND p126-127
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Continuous vs Discrete Variation
 Define variation, continuous and discrete
variation. Discuss the advantages of variation
ND p128-129 Ex7B
ND Prac56 p16
ESA p79
Year 11 Science
e.g. evolution and natural selection.
ACTIVITY: Measure height (or other continuous
variation) and then graph results.
Measure discrete variations.
ACTIVITY: Variation in a Species worksheets (good)
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Mendelian Genetics
 Background reading on Gregor Mendel’s work
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ND p132-135 Ex 7D, 7E
ND p142-143 Ex 7I
ESA p80-84
Simple monohybrid inheritance
To start punnet squares do Male and Female and
ESA p75
find out why 50:50 ratio in population.
Punnet square problems. Emphasise ratios
Hmwk: ESA p84-89
and % of phenotype and genotype. Also that
these are predicted outcomes, not what will
always happen due to randomness of sex.
Interpret pedigree charts (family trees).
Define: gametes, zygote, complete
dominance, recessive, homozygous,
heterozygous, pure breeding, punnet square,
phenotype, genotype (ratios), back or
testcross and pedigree chart.
(determination of sex)
Mutations
 Define what a mutation is.
 Change to base sequence in DNA.
 Results in change in amino acid sequence.
 Can result in phenotype change.
Genetic problems
 Analyse pedigree chart for conditions such as
haemophilia, colour blindness etc
Year 11 Science
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Adaptations and natural selection
 Discuss how living things need to adapt to
changing environments.
 Survival of the fittest and natural selection.
 Explain how useful characteristics are passed on
to the next generation and how less fit
individuals die before they can pass on their
genes.
 Discuss the role of useful mutations as being
responsible for special adaptations of species.
 Choose an animal and list adaptations and why
those adaptations enable it to survive and
eventually reproduce.
Evolution
 Explain how useful mutations are selected for.
 Show ‘Evolution’ Powerpoint which uses
evolution of elephants as a case study.
Revision
Complete fractured sentences revision exercise
(literacy exercise). Envelope in folder or box in
resource room.
Test
Show Brainbops animation:
 Natural Selection
Life of Mammals – Show an episode and discuss the adaptations
that help the animal survive and reproduce.
‘Evolution’ Powerpoint in K-drive
T&L Literacy: Fractured sentences in folder.
Unit test