Zusammenfassung der Ressource
Biology-B1
- Variation
- indiviuals of the same
species
- can be caused by...
- genetic factors, e.g. dimples, eye colour
- environmental factors,e.g. scars, hair style
- Genetic Information
- DNA
- genes
- located in the NUCLEUS of every cell
- occur in long strips called CHROMOSOMES
- control the development of different characteristics with instructions to the cells
- alleles
- dominant
- controls the development of a characteristic even if its present on only one chromosome in a pair
- recessive
- controls the development of a characteristic only if the dominant allele is not present
- homozygous: inherit two which are the same
- heterozygous: inherit two which are different
- instructions for...
- how the organism should be constructed
- how each cell should function
- Chromosomes
- made of DNA molecules
- double helix
- come in pairs
- both cromosomes in the pair have the same sequence of genes,
- same genes in the same place
- Humans have 23 pairs, 46 chromosomes in total
- sex cells contain single chromosomes
- protein
- structural
- for cell growth of repair
- functional
- enzymes to speed up chemical reactions
- GENETIC DISORDERS
- HUNTINGTON'S
- one faulty allele, on the fourth pair of chromosomes
- affects the central nevous system
- damages brain cells
- gradual changes=symptoms
- involuntary movement
- clumsiness
- memory loss
- mood changes
- inability to concentrate
- develop in adulthood
- means sufferers have already passed it onto their offspring
- incurable=premature death
- only one parent needs to pass on the gene fora child to inherit it
- allele is dominant
- CYSTIC FIBROSIS
- causes the build up of thick sticky mucus
- lungs,hut and pancreas
- symptoms
- weight loss
- difficulty in breating
- chest infections
- difficulty in digesting food
- if a person has one of the alleles, doesn't have any symptoms=carrier
- they can pass on the allele to offspring
- an example of this=SICKLE CELL
- GENETIC TESTING
- testing for a faulty allele
- implications
- testing individuals for...
- suspectability to certain diseases or conditions
- possible problems with certain prescribed drugs /treatments
- stem cells
- develop into specialised cells neede in an organism
- adult
- taken from areas which are adapted for replacement /repair of tissues
- umbilical cord and bone marrow
- can develop into a range of specialised cells but not all types
- embryonic
- taken from a developing embryo, to make into necessary clone embryos
- develop into any kind of specialised cell
- used to replace damaged tissue, patients with parkinsons disease