Genetics Flashcards
Genome
All the genetic material of an organism
Chromosome
Made up of DNA. Sections of a chromosomes are called genes
Gene
Section of chromosome that codes for a characteristic
Allele
Different forms of the same gene e.g. Gene for eye colour - alleles may be brown, blue, green
DNA
Made up of nucelotides - which contain a deoxyribose sugar, phosphate group and a base
Bases found in DNA
A (adenine)
T (Thymine)
C (Cytosine)
G (Guanine)
Which bases form base pairs with each other
A with T
C with G
Name of the shape of a DNA molecule
Double Helix
Antiparallel strands
The two strands of DNA run in opposite direction to each other
What does DNA code for
A protein
What is the triplet code
The order of 3 bases that code for a particular amino acid
If a gene is made up of 60 bases on the coding strand, how many amino acids is this protein made up of
3 bases = 1 amino acid
60 bases = 20 amino acids
the protein that this gene codes for is made up of 20 amino acids
If a protein is made up of 15 amino acids. What is the minimum number of bases required in the gene that codes for this protein
3 bases = 1 amino acid
This protein has 15 amino acid so
15 x 3 bases = 45 bases required
What are the 2 types of cell division
Mitosis and Meiosis
Which cell division produces cells that are genetically identical
Mitosis
Which cell division produces cells that are genetically different
Meiosis
What is mitosis used for
Growth
Replace worn out cells
Repair damaged tissues
Asexual reproduction
What is meiosis used for
Producing sex cells - gametes
Before cell division occurs what happens to the number of chromosomes
The number doubles - the chromosomes make a copy of themselves before division
In mitosis describe what happens
The chromosomes duplicate themselves (e.g. go from 46 chromosomes to 92 chromosomes)
The cell divides in 1 division
Produces 2 diploid daughter cells (each containing 46 chromosomes)
All genetically identical to parent cell and each other
Describe what happens during meiosis
The chromosomes duplicate themselves (e.g. go from 46 chromosomes to 92 chromosomes)
The cell divides twice - 2 divisions
Produces 4 haploid daughter cells (each containing 23 chromosomes)
All genetically different