Download OB35

Genetics
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1B5 Genetics
inheritable and
non-inheritable
characteristics,
chromosomes
and genes
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1B5 Genetics
OB35
understand that humans have inheritable and noninheritable characteristics, and that inheritable
characteristics are controlled by genes
OB36
recall that genes are located on chromosomes and that in
a human there are 23 pairs of chromosomes, which are
located in the nucleus
OB37
recall that chromosomes are made of DNA
and protein
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OB35
understand that humans have inheritable and non-inheritable
characteristics
some characteristics are
passed on from parents
to children – these are
called inheritable…
these characteristics
may in turn be passed
on to the following
generation(s)…
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other characteristics are
independent of
parentage – these are
called non-inheritable…
these characteristics will
not be passed on to the
following generation(s)…
OB35
understand that humans have inheritable and non-inheritable
characteristics
Inheritable characteristics are received
from parents…
father
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mother
OB35
understand that humans have inheritable and non-inheritable
characteristics
Check out some of your own inheritable
characteristics…
 Arm fold preference
 “Hitchhiker’s thumb”
 Pinkie finger alignment
 Ear lobe attachment
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Check out your own…
Arm fold preference: fold your arms -
?Do you fold right-over-left or left-over-right?
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Check out your own
“Hitchhiker’s thumb”: extend your thumb –
? Is it straight or curved?
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Check out your own …
 Pinkie fingers: place them side by side –
? Are they straight or curved away from each other?
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Check out own …
 Ear lobes: look at your ear in a mirror –
? Is it directly attached or separated ?
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Other inheritable characteristics include:
eye
colour
freckles
blood type
haemophilia
cystic
fibrosis
If you are connected to the internet, some of the images will link you to a source of information
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OB35
understand that humans have inheritable and non-inheritable
characteristics
Some non-inheritable characteristics:
 Athletic ability
 Artistic ability
 Accent
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OB35
understand that inheritable characteristics are controlled by genes
For each inheritable characteristic, a
human has two genes – one passed on
by the father’s sperm cell, the other by
the mother’s egg cell
two genes
for eye
colour
one gene
for eye
colour
one gene
for eye
colour
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OB36
recall that genes are located on chromosomes which are located in
the nucleus
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OB36
recall that genes are located on chromosomes which are located in
the nucleus
image from http://regentsprep.org/Regents/biology/units/heredity/dna.cfm
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OB36
recall that in a human there are 23 pairs of chromosomes, which
are located in the nucleus
©news.bbc.co.uk
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OB37
recall that chromosomes are made of DNA and protein
• DNA stands for deoxyribonucleic acid
• it is a molecule built in a particular code
• the code contains instructions for every
structure and function the body will ever need
• the DNA code for each separate structure or
function is called a gene
• this makes it a very very long molecule…so
how does it fit into a very tiny nucleus?
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OB37
recall that chromosomes are made of DNA and protein
© 2005 Chugoku Rosai Hospital
• the long DNA molecule is so twisted and coiled so that it
takes up tiny little space…
• each twisted coil of DNA, containing many genes, makes
one chromosome…
• small molecules of protein help keep the chromosome in
shape
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OB37
recall that chromosomes are made of DNA and protein
• the code in DNA is different in every
human being…(except for ?????)
• Each individual’s unique code is called
their DNA fingerprint
• because of this, DNA is used in
• crime scene investigation
• parental disputes
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OB37
recall that chromosomes are made of DNA and protein
• the code in DNA is different in every
human being…except for ?????
IDENTICAL TWINS
can you explain why
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OB37
recall that chromosomes are made of DNA and protein
How small is DNA?
If you are connected to the internet, click on the
image below to get an idea
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Genetics
OB35
understand that humans have inheritable and noninheritable characteristics, and that inheritable
characteristics are controlled by genes
OB36
recall that genes are located on chromosomes and that in
a human there are 23 pairs of chromosomes, which are
located in the nucleus
OB37
recall that chromosomes are made of DNA
and protein
www.juniorscience.ie