Zusammenfassung der Ressource
B1 Variation and
inheritance
- Inherited characteristics
- Some human characteristics such as facial
features can be inherited. They can be
dominant or recessive
- Alleles are different versions of
the same gene
- Chromosomes
- Most body have the same number of
chromosomes. The number depends on
the species of organism. Humans have
23 paris
- Sex chromosomes determine sex in mammals.
Females have identical sex chromosome called
XX, males have different sex chromosomes
called XY
- A sperm will carry either
and X or a Y
chromosomes. All eggs
will carry and X
chromosome
- Genetic Variation
- Genetic variation is caused by mutations
which are random changes in genes or
chromosomes
- A monohybrid cross
- A monohybrid cross involves only one pair of
characteristics controlled by a single gene, one allele
being dominant and one recessive
- Homeozygous means having identical alleles,
heterozygous mean having different alleles
- A persons genotype is their genetic make-up,
heterozygous means having different alleles
- Inherited disorders
- They are caused by faulty genes
- Many person and ethical issues are raised;
in deciding to have a genetic test, by
knowing the risks of passing on and
inherited disorder
- Inherited disorders are caused
by faulty alleles