1. What is the beginning phase of meiosis?
1. Please have these
Items on your desk.
Agenda
Science Starters
Sheet
What is the beginning phase of meiosis?
What occurs during this phase?
Friday January 27, Day 2

2. Table Of Contents 1/27 (Blue) Mitosis/Meiosis Station Work pg 15
1/27 (Purple) DNA Notes pg 16-17

3. 1
DNA
The illustration is a ‘model’ of the double helix forming part of a DNA molecule
(Slide 14)

4. DNA stands for deoxyribose nucleic acid2
DNA stands for deoxyribose nucleic acid
This chemical substance is present in the nucleus
of all cells in all living organisms
DNA controls all the chemical changes which
take place in cells
The kind of cell which is formed and The kind of organism which is produced , (muscle, blood,
nerve etc) is controlled by DNA

5. DNA is a very large molecule made up of a long chain of sub-units
DNA molecule 3
DNA is a very large molecule made up of a long
chain of sub-units
The sub-units are called nucleotides
DNA molecule
a sugar called deoxyribose
a phosphate group -PO4 and
an organic base

6. Deoxyribose is almost the same as sugar but lacks one oxygen atom4
Deoxyribose is almost the same as sugar but lacks
one oxygen atom
represented by the symbol

7. The most common organic bases are
The bases 5
The most common organic bases are
Adenine
(A)
Thymine
(T)
Cytosine
(C)
Guanine
(G)

8. Combine to form a nucleotide
Nucleotides 6
The deoxyribose,
the phosphate
and one of the bases
Combine to form a nucleotide
adenine
deoxyribose
PO4
It is the phosphate group which gives DNA its acidic properties

9. Joined nucleotides 7
PO4
sugar-phosphate
backbone
+ bases
A molecule of DNA is formed by millions of nucleotides joined together in a long chain

10. DNA Structure In fact, the DNA usually consists of a double8
DNA Structure
In fact, the DNA usually consists of a double
strand of nucleotides
The sugar-phosphate chains are on the outside
and the strands are held together by chemical
bonds between the bases

11. 2-stranded DNA 9
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4