Leaving Cert Biology Genetics Flashcards
Chromosome
A structure made of DNA and protein which can be inherited.
Gene
A section of DNA that contains the instructions for the formation of a protein
Gene Expression
The way in which the genetic information in a gene is decoded in the cell and used to make a protein
Non-coding DNA
DNA that does not cause the production of a protein
Genetic Code
The sequence of bases in DNA that provide the instruction for a cell (using RNA) to form a protein
Codon
A sequence of three bases in DNA or RNA that acts as a code for an amino acid
DNA profile
A metheod of making a unique pattern of bands from the DNA of a person which can then be used to compare with the DNA profile of another person
Genetic Screening
Testing DNA for the presence of the presence or absence of a particular gene
Diploid
Having two sets of chromosomes in the nucleus
Haploid
Having only one set of chromosomes
Homologous Pair
Two chromosomes of similar size with the same sequence of genes
Centromere
The poinat which chromosomes are attached in a double stranded chromosome
Cancer
A group of disorders in which certain cells lose their ability to control both the rate of mitosis and the number of times mitosis takes place
Cell Cycle
The changes that take place in a cell during the period between one cell division and the next
Interphase
The phase in a cell cycle when the cell is not dividing
Mitosis
A form of nuclear division in which on nucleus divides to form two identical nuclei
Meiosis
A form of nuclear division in which on nucleus divides to form four daughter nuclei, each with half the number of chromosomes as the parent nucleus
Allele
different forms of the same gene
Genotype
genetic makeup of an organism, genes which are present
Phenotype
physical make up or appearance of an organism
Law of Segregation
Inherited characteristics are controlled by pairs of factorsThese factors segregate from one another at gamete formation, with only one member of the pair being found in each gamete.We know know these as alleles.
Law of Independent Assortment
When gametes are formed either of a pair of factors is equally likely to combine with either of another pair of factors
Sex linkage
A characteristic is controlled by a gene on an X chromosome. Males suffer more often with sex linked characteristics EG: Duchenne muscular dystrophy, colour blindness
Sickle Cell Anaemia
Inherited blood disorder caused by a mutation in the haemoglobin gene
Down's Syndrome
Example of a chromosome mutation caused by the presence of one extra chromosome. Fault arises in meiosis where the egg has two number 21 chromosomes and then the sperm adds a third
Mutagens
Agents that cause mutation, rate of mutation is speeded up. eg: ionizing radiation in Xrays
Evidence of evolution (3 sources)
fossilscomparative anatomycomparative embyrology
Fossil
remains of, or a product of an ancient organism
Evolution
leads to the formation of a new species.the way in which genetic changes produce different types of organisms over time
Acquired variation
learned during life
Inherited variation
caused by genes