Inheritance Flashcards
Gene definition
A section of DNA which codes for a specific protein
Homozygous definition
Two alleles for a characteristic are the same
Dominant definition
Only one copy is needed of this allele to be expressed in the phenotype
Haploid definition
Half the number of chromosomes, 23, sex cells
Heterozygous definition
Two alleles for a characteristic are different
Co-dominant definition
When two different alleles are both expressed in the phenotype
Recessive definition
Two copies of this allele are needed to be expressed in the phenotype
Phenotype definition
Physical expression of the gene
Chromosome definition
Made of DNA, containing thousands of genes
Diploid definition
Chromosome number in normal body cell, 46
Allele definition
A specific version of a gene
Homologous definition
Pair of chromosomes with the same sequence of genes
Genotype definition
Describes the alleles for a specific characteristic
Where are chromosomes found
In the nucleus, on which genes are located
What is a nucleotide made of
- phosphate
- sugar (deoxyribose)
- organic base
- covalent bonds
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
Facts about double helix
- anti-parallel to each other
- fixed together by hydrogen bonds
What is mitosis used for
- to repair
- growth
- cloning
- asexual reproduction
Differences between mitosis and meiosis
Mitosis:
- starts off with 46 chromosomes
- finishes off with two identical cells
Meiosis:
- starts off with 46 chromosomes
- divides twice
- finishes with only 23 chromosomes
- produces 4 daughter cells
- all genetically different haploid gametes
Who is responsible for determining the sex
Dad
Suggest other information the doctor could use to decide if someone has…
Look at a combination of symptoms analyse DNA
look at family history
Explain how examining a family pedigree you would be able to tell if a condition was caused by a recessive allele
If both parents were unaffected but their offspring was affected. This shows that both parents had a recessive allele is but did not possess the disease so they are carriers.
What is a monohybrid cross
It is when all of the offspring have the allele Aa, so one parent is AA and the other is aa
