Life Sciences Gr. 12 2014 – Term 1 NOTES
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starting on 1st left hand page. Complete questions after pages are pasted flat.
Strand 1: Life at Molecular, Cellular & Tissue level
Date: ____________
DNA: The code of Life
First of all, some revision:
Regard the labelled diagram below, and complete the functions of the indicated
labelled parts. Use your textbook and prior knowledge to do this.
Remember to focus on how these parts apply to what you will be studying in this
section = DNA and how it carries information to form every part of all organisms on
the planet.
Smooth ER
Nucleopore
Nucleomembrane
Chromatin network (DNA)
Nucleolus
Nucleoplasm
Rough ER
Ribosomes
ER
Nucleopore
Ribosomes
Nucleolus
Chromatin Network
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Life Sciences Gr. 12 2014 – Term 1 NOTES
Cut out along provided dashed border, paste in,
starting on 1st left hand page. Complete questions after pages are pasted flat.
Location of DNA:
Nucleus
DNA contained within a nucleus of
eukaryotic organisms.
Nuclear DNA encodes for the majority of
the genome in eukaryotes. Nuclear DNA
adheres to Mendelian inheritance, with
information coming from two parents,
one male, and one female. One parent
will possess a dominant genome and the
other a recessive genome. When
combined during fertilization, the child
has the dominant characteristic visible,
but the recessive characteristic is carried
and possibly passed to the following
generation.
Mitochondrion
DNA located in mitochondria and plastids
coding for the rest of the remaining
genome not coded for in nuclear DNA.
Is inherited directly from the mother
through the egg cell during fertilization.
Remains unchanged through countless
generations, is one of the points of
evidence for the ‘Out-of-Africa’ theory
when evolution is discussed.
Genome: the haploid set of chromosomes in a gamete or microorganism, or in each
cell of a multi-cellular organism.
Mendelian: Austrian monk who first experimented with dominant and recessive
inheritance. You will learn more about this when we do the ‘Genetics’ section.
Haploid: meaning half of the complete set of genetic information inherited from the
parents. Humans have 46 chromosomes, 23 from mother and 23 from father. The 46
full set is referred to as Diploid, the 23 half set is referred to as the haploid
chromosome / genome number.
Gamete: the non-specific name for a reproductive cell, either male (sperm) or female
(egg cell).
Gene: a unit of heredity which is transferred from a parent to offspring and is held to
determine some characteristic of the offspring. Humans have numerous genes that
are all located on different places on a chromosome. These gene locations are
called a Locus.
Heredity: the passing on of physical or mental characteristics genetically from one
generation to another.
There is still a lot of debate regarding the ‘mental’ characteristics being passed from
parent to child. Yes there has been evidence presented that certain conditions such as
Schizophrenia, Bipolarism etc. are passed from parent to child, but there has been an
almost equal amount of evidence that indicates that experiences through childhood or
life can trigger these conditions also. So the jury is still out on that one .
Numerous studies focus on early childhood stimulation as evidence for higher IQ, not
really genetics. But if the parents don’t know better (education, IQ etc.) how will they
know how to properly stimulate their child’s development? It can become a nice
circular argument if you wish.
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Life Sciences Gr. 12 2014 – Term 1 NOTES
Cut out along provided dashed border, paste in,
starting on 1st left hand page. Complete questions after pages are pasted flat.
QUESTIONS:
1) Study the data below and complete the family tree. Disregard all other factors
except dominance and recessiveness of traits / characteristics.
DOMINANT TRAITS
RECESSIVE TRAITS
eye colouring
brown eyes
grey, green, hazel, blue eyes
vision
farsightedness
normal vision
normal vision
normal vision
normal vision
nearsightedness
night blindness
colour blindness
hair
dark hair
non-red hair
curly hair
full head of hair
widow's peak
blonde, light, red hair
red hair
straight hair
baldness
normal hairline
PETER
Brown eyes
PAUL
MARY
Blue eyes
JOHN
MARK
SARAH
Brown eyes
JOHN Jnr
JESSICA
Green eyes
2) Do you think it is at all possible for Mark and John Jnr to have anything
besides Brown eye colour? Explain your answer (shortly! This is not an essay
question!)
3) What do you think would be the consequences of the nuclear membrane NOT
having nucleopores?
4) Why is the relatively close location of ribosomes to the nucleus of biological
importance?
HOW MUCH DO YOU REMEMBER?
5) What is the chromosome difference between males and females?
6) What are the monomers of proteins?
7) Name 3 bodily structures that are formed by proteins.
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