UNIT 18: INHERITANCE
Inheritance: transmission of genetic information from generation to generation
Chromosome: a thread-like structure of DNA, carrying genetic information in form
of genes
Gene: a length of DNA that codes for a protein
Allele: a version of a gene
23 pairs of chromosome in human (1 is sex
chromosomes)
These determine the sex of the individual
Males have XY, females have XX -> only the males
can provide Y chromosome -> sex is determined by
father -> 50% female or male
DNA (Deoxyribonucleic acid)
Sequence of bases in a gene is genetic code for putting together amino acids in
correct order to make a specific protein
There are only 4 different types of bases
1. Adenine (A) 2. Cytosine (C)
3. Guanine (G) 4. Thymine (T)
Genetic code is used to make new cells by making proteins
Controls cell function by controlling production of proteins,
antibodies, receptors for neurotransmitters
All body cells contain same genes, but many genes in a
particular cell are not expressed because cell only makes specific proteins it
needs
The process of making a protein molecule:
1. The gene coding for the protein remains in the nucleus
2. mRNA molecules carry a copy of the gene in the cytoplasm
3. The mRNA passes through ribosomes
4. The ribosomes assembles amino acids into protein molecules
5. The specific order of amino acids is determined by the sequence of bases in
the mRNA
Haploid: a nucleus containing a single set of unpaired chromosome e.g. in gametes
Diploid: a nucleus containing 2 sets of chromosome e.g. in body cells
In a diploid cell, there is a pair of each type of chromosome
In a human diploid cell there are 23 pairs
Mitosis: Nuclear division that gives rise to genetically identical cells
Inheritance: transmission of genetic information from generation to generation
Chromosome: a thread-like structure of DNA, carrying genetic information in form
of genes
Gene: a length of DNA that codes for a protein
Allele: a version of a gene
23 pairs of chromosome in human (1 is sex
chromosomes)
These determine the sex of the individual
Males have XY, females have XX -> only the males
can provide Y chromosome -> sex is determined by
father -> 50% female or male
DNA (Deoxyribonucleic acid)
Sequence of bases in a gene is genetic code for putting together amino acids in
correct order to make a specific protein
There are only 4 different types of bases
1. Adenine (A) 2. Cytosine (C)
3. Guanine (G) 4. Thymine (T)
Genetic code is used to make new cells by making proteins
Controls cell function by controlling production of proteins,
antibodies, receptors for neurotransmitters
All body cells contain same genes, but many genes in a
particular cell are not expressed because cell only makes specific proteins it
needs
The process of making a protein molecule:
1. The gene coding for the protein remains in the nucleus
2. mRNA molecules carry a copy of the gene in the cytoplasm
3. The mRNA passes through ribosomes
4. The ribosomes assembles amino acids into protein molecules
5. The specific order of amino acids is determined by the sequence of bases in
the mRNA
Haploid: a nucleus containing a single set of unpaired chromosome e.g. in gametes
Diploid: a nucleus containing 2 sets of chromosome e.g. in body cells
In a diploid cell, there is a pair of each type of chromosome
In a human diploid cell there are 23 pairs
Mitosis: Nuclear division that gives rise to genetically identical cells
