Summary Year 10 Curriculum Biology Mid Topic Revision

Yr10-Science-Biology Mid Topic
Revision
The Nucleus
Prokaryotic
 Example: bacteria
 Unicellular
 Organelles are not membrane bound
 No true nucleolus… DNA contained in organelle called nucleoid
 Very small
Eukaryotic
 Examples: plants, animal, fundi
 Larger more complex cell
 Containing membrane bound organelles
 True nucleous that contains DNA

What are the functions of the nucleus?
To hold DNA

DNA
What is DNA?
Cell replicating material that is in all living organism.

Molecular structure:
 Nucleotides=phosphate+sugar and base (adenine, thymine, cytosine, guanine)
 double helix=when one side of the repeated nucleotides join to the other and the
bases pair to the corresponding ones (A+T and C+G)
 base pairing= A+T and C+G

DNA, Genes and Chromosomes
Genes
 units of heredity, blueprints for protein production.
 A section of a chromosome

Chromosomes and karyotypes
 made from DNA tightly wrapped around proteins called histones.
 We have 46 chromosomes or 23 pairs
 22= autosomal
 1=sex chromosomes (X and Y)
 A karyotype is an individual's complete set of chromosomes.
 In Plant and animal nucleuses