18- inheritance Flashcards
inheritance
The transmission of genetic information from one generation to the next.
chromosomes
Thread like structure of DNA, carrying genetic information in forms of genes.
gene
Length of DNA and codes for a protein
allele
Is a version (form) of gene
nucleotides
the building up component of the DNA
components of nucleotides
base, sugar and phosphate group
shape of DNA
double helix
pairs DNA is found in
Aā-T
Cā-G
how does DNA control cell function
by controlling the production of proteins
how many bases are needed to code for one amino acids
3 (triplet code)
where does protein synthesis occur
in the ribosome in the cytoplasm- it assembles amino acids to protein molecules
job of messenger RNA
carries a copy of gene to the cytoplasm to pass it to the ribosomes.
how is the specific order of amino acids determined
by the sequence of bases in the mRNA
mitosis
nuclear division giving rise to genetically identical cells
role of mitosis
- growth
- repair
- asexual reproduction
stem cells
unspecialized cells that divide by mitosis to produce daughter cells that become specialized for specific functions.
meiosis
Nuclear division in which the chromosome number is halved resulting in genetically different cells, and produce genetic variation.
genotype
genetic make-up of an organism in terms of the alleles present.
phenotypes
observable features of an organism.
heterozygous
having two different alleles of a particular gene.
homozygous
having two identical alleles of a particular gene.
dominant
an allele that is expressed if it is present.
recessive
an allele that is only expressed when there is no dominant allele of the gene present.
ways of showing the phenotype of a particular gene
- pedigree diagrams
- genetic diagrams
- punnett squares
codominance
When neither of a pair of alleles is completely dominant or completely recessive, so both of them have an effect on the phenotype. eg; blood type
alleles of blood types
IA IB- codominant
IO- recessive to both of the above
sex linked characteristic
characteristic in which the gene responsible is located on a sex chromosome making it more common in one sex than in the other.
pure breeding
the breed of two organisms identically homozygous for a particular characteristics, producing offspring with exactly the same genotype and phenotype as the parents
monohybrid inheritance
the inheritance of characteristics controlled by a single gene
how are unknown genotypes identified
test cross
test cross
breeding the unknown individual with an individual showing the recessive phenotype.
