DNA

Question 1

Describe the process of cell division

Answer 1

• DNA strands are bound to histones(proteins)
• DNA strands coil around the histones so they can fit into the small space of the nucleus
• in a cell that is not dividing, the coiled DNA forms a tangled network called a chromatin
• when a cell is about to divide, the chromatin becomes more tightly coiled and become known as chromosomes

Question 2

Describe the structure of a DNA molecule

Answer 2

Consist of two strands of alternating sugars and phosphates, with pairs of nitrogen bases linking the sugars and phosphates.

A phosphate group and sugar molecule with a nitrogen base is called a nucleotide.

The bond between nitrogen base pairs are a weak hydrogen bond that can be broken easily for DNA replication

Question 3

What is DNA?

Answer 3

Deoxyribonucleic acid. It is found in the nucleus of a cell. Contains the genetic information that determines the structure of a cell and its functions

Question 4

Mitosis

Answer 4

Interphase- when the cell is not yet dividing

              - chromosomes not yet visible
              - (inter)phase not much happens, like on the (Inter)net 

Prophase- chromosomes condense and appear

            - spindle forms
            - (pro)phase things start to get (pro)ductive

Metaphase- chromosomes move to equator of the cell

               - chromosomes become attached to spindle fibres
               - (m) for middle of the cell

Anaphase- increasing separation of the fibres
- (shaped like a peanut) people can go through (anaph)ylactic shock from peanuts

Telophase- splitting of cell membrane

              - forming of two new cells
             - (telo)phase starts to separate, like when you are on the (telo)phone

Question 5

Meiosis

Answer 5

One the first stages of division(mitosis) take place the second stages begin.

Prophase2- two cells are now haploid(23 chromosomes)

              - each daughter cell undergoes division, however, resulting in four new haploid cells
              - chromosomes in each cell move towards the equator

Metaphase2- chromosomes are arranged on new spindle

Anaphase2- new chromosomes move to the opposite poles of the cell
- nuclear membranes begin to form

Telophase2- cytoplasm starts to divide
- by end of second division, four new cells have formed