Download Genetics * Learning Outcomes

1
Genetics – Learning Outcomes
 Understand inheritable and non-inheritable
characteristics.
 Know that inheritable characteristics are controlled by
genes.
 HL: Recall where genes are located.
 HL: Recall the number of pairs of chromosomes in
humans.
 HL: Recall the location of chromosomes.
 HL: Recall the composition of chromosomes.
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Understand Inheritable Characteristics
 Some
characteristics of
people are
controlled by
genetics.
 These are called
inheritable
characteristics.
 Some examples
are hair colour,
eye colour, hair
line, toe length,
and knuckle hair.
by LeuschteLampe – public domain
3
Understand Non-Inheritable Characteristics
 Some characteristics are not inherited – they are picked
up over the course of a life.
 These are called non-inheritable characteristics.
 Some examples are learned skills, behaviour, food
preferences, and sport preferences.
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Inheritable or Non-Inheritable?
Characteristic
Ability to speak French
Ability to roll your tongue
Hair colour
How tall you are
Eye colour
How good you are at maths
Whether you will get heart
disease
Whether you like cucumber
How fast you can run
Inheritable Non-Inheritable
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What Controls Characteristics?
 The study of inherited characteristics is called genetics,
because they are controlled by genes.
 Genes are passed from parents to children when
reproduction occurs.
 Everyone gets two copies of each gene – one from their
mother and one from their father.
 Usually, only one of these copies will affect you – this is
called a dominant gene.
 The copy of the gene that does not affect you is called
the recessive gene.
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What Controls Characteristics?
 e.g. Brown hair is dominant, while blond hair is recessive.
Mother’s Gene
Brown
Brown
Blond
Blond
Father’s Gene
Brown
Blond
Brown
Blond
Your hair colour
Brown
Brown
Brown
Blond
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What Controls Characteristics?
 This does not mean that two brown-haired parents can
only have brown-haired children.
 Each parent has two genes also, but only passes one to
their child.
 If they both pass a blond gene to their child, the child
can be blond, even if both parents have brown hair.
Father
Passes
Brown
Mother Passes
Brown
Blond
Brown
Brown
Blond
Brown
Blond
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HL: Locate Chromosomes
 Genes are located on chromosomes.
 Each cell in a given human contains the same 23 pairs
of chromosomes in the nucleus.
 Sperm also have a tail which is used for swimming.
by Earthdirt – CC-BY-SA-3.0
by Henry Gray – public domain