Inheritance and Genetic Diseases Flashcards
What is a chromosome
Long thread like structures of DNA
What’s a gene
A short section of DNA, coding for a particular protein
What is RNA
Copy of DNA which leaves the nucleus to go to the ribosome.
What is an allele
Different versions of the same gene
Genome =…………………..
The entire DNA of an organism
In DNA what forms the rungs between the two backbones
Complementary base pairs
Which base pairs pair with which
A-T
C-G
When is a U used instead of a T
In RNA
Is RNA single or double stranded
Single
What is transcription
The process of making a copy of genetic information in the form of mRNA.
What is mRNA
Single stranded, moves out of the nucleus to the ribosome
What is translation
The process by which the code on the mRNA is used to make protiens
Describe the process of Transcription (5)
The DNA unzips
RNA Polymerase binds to the DNA
mRNA bases from complementary base pairs with DNA
RNA Polymerase joins the mRNA bases together
The finished mRNA strand leaves the nucleus through it’s pores
How does translation work (6)
The ribosome binds to the mRNA
The mRNA is read 3 bases at a time. 3 bases = 1 codon
tRNA has a specific amino acid attached + a anticodon
The tRNA anticodon is complementary to the codon
The order of amino acids brought to the ribosome is determined by the order of codons
The ribosome moves along the mRNA, reading it one codon at a time and binding amino acids together to form a protein
Define asexual reproduction
Does not require a mate. Can reproduce by mitosis.
What is mitosis used for
Growth
Repair
Replacement
Outline the process of mitosis
In the cells the DNA is replicated. The chromosomes each make a replica of themselves so there are two sets of each.
The chromosomes are then pulled to either side of the cell, with one from each pair one each side. Two genetically identical daughter cells are produced.
Dominant always…….recessive
Beats
For the recessive trait to be expressed, you need…………………………………..
Two copies of the recessive alleles
What is a phenotype
Physical characteristic
Heterozygous = …………………
Two different allele present (B,b)
Homozygous = …………………….
Only one type of alley present (B,B)
How would you lay out a possible outcome question
Parent phenotype
Parent genotype
Gamete genotype
Punnet square
Offspring phenotype
give the 3 pedigree rules
Dominant disorders can’t jump generations but recessive ones can
It is impossible for two people with a recessive disorder to have a child without the disorder
It is possible for two people with a dominant disorder to have a child without the disorder. 25% chance. (H,h x H,h
What letters do we give to sex chromosomes
X and Y
What two chromosomes are needed for a male
XY
What two chromosomes are needed for a female
XX
