5.4 From Mendel to DNA Flashcards
What was Mendel the first person to suggest?
The idea of separately inherited factors
Why did it take a long time for Mendel’s idea to be accepted?
Scientists didn’t know about genes and chromosomes until after Mendel had died
What are Mendel’s factors now known as?
Genes
What are genes?
Short sections of DNA, which is a very long molecule with a double helix structure
What is a DNA fingerprint?
A unique DNA pattern used to identify people, except identical twins
What do our chromosomes control?
Our characteristics
What are chromosomes?
Large DNA molecules
What is a gene made up of?
3 pairs of bases that code for a specific amino acid that join together to make proteins
What letters are the bases made of?
C, A, T, G
Name 3 effects of copying errors (mistakes in the bases)
- they could work better
- they could do nothing at all
- they could stop it from working
What do mutations cause?
Different proteins
What is a phenotype?
A physical aspect of the offspring, coded by a pair of chromosomes, one from the mother, one from the father
What do all of your chromosomes make?
A genome
In the inheritance punnet squares, how are the dominant alleles written?
As capital letters, the first letter of the word, eg. B for brown eyes
In the inheritance punnet squares, how are the recessive alleles written?
As little letters, the first letter of the word, eg. b for blue eyes
Define the dominant allele.
The characteristic that will appear in the phenotype of someone even if only one allele for it is inherited
Define the recessive allele
The characteristic that will only appear in the phenotype if both of those alleles are inherited
Define the phenotype of someone
Their physical appearance regarding a particular aspect
Define genotype
The genetic make up regarding a particular aspect
What does homozygous mean in regard to alleles?
Someone with 2 identical alleles for a characteristic
What does heterozygous mean in regard to alleles?
Someone with 2 different alleles for a characteristic, the dominant one will decide the phenotype
How can you predict a certain phenotype of an unborn child?
Compare the genotypes of the parents and calculate the percentage for each child’s genotype using a punnet square
Who was Gregor Mendel?
A monk who discovered how characteristics were inherited
