Topic M: Inheritence Flashcards
Theoretically what are genes?
Genes are units on inheritance, Organism differ because they have different genes.
When a protein is required…..?
The gene on the DNA is copied (transcribed) to messenger RNA (MRNA)
What does the MRNA do when it has the copy of DNA?
The MRNA leaves the nucleus and goes to a structure called a ribosome. Where the code is transferred into the relevant protein from individual amino acids.
What is a codon?
Each amino acid is coded for by a sequence of 3 bases. This sequence is called a codon.
Does DNA ever leave the nucleus?
No it stays in the nucleus, but proteins are built in the cells cytoplasm.
How many chromosomes does a human cell have?
23 pairs, 23 from each parent, 46 in total.
Genetic information is stored in the?
Nucleus
Each chromosome is made of a very long molecule of?
DNA
How much DNA is there in each human cell?
2m, it has to be very tightly coiled for cell division.
Describe the shape of the DNA?
The DNA molecule is a double Helix, like a twisted rope ladder.
Each rung in the ladder has a pair of…?
bases
What are the four different bases called?
Adenine, Thymine, Guanine and Cytosine
Because of there shape they can only pair with each other in certain ways?
A -> T and G -> C
Definition of a Gene?
A gene is the length of DNA which codes for making one protein molecule.
What is Genetic engineering?
Living things naturally create useful products. Genetic engineering can be used to make living things produce other, more valuable products.
Examples of genetic engineering?
Bacteria and yeasts can be genetically modified (there DNA changed) to mass produce products such as insulin, growth hormone. The insulin produced would be human insulin.
What were the alternatives of genetic engineering?
Getting the insulin out of the pancreas of a pig, a by product of the meet industry. The disadvantages of this were that it could be an allergen and it was not efficient to make it in larger numbers.
The purpose of GM crops?
Crops can be given extra genes for new and useful characteristics.
What characteristic may be needed in Gm crops
- pest resistance
- frost resistant
- disease resistance
- drought resistance
Production of insulin by genetically modifying bacteria?
LOOK IN WORK BOOK PAGE 16-17
What is Mitosis?
This form of cell division produces identical copies of the parent cell. The DNA replicates; the chromosomes from a pair of chromatides. The cell than divides to produce two identical daughter-cells.
When is Mitosis used?
Mitosis is used for the growth and repair of tissues (from the zygote stage on-wards.