Flashcards in Genetics 1, 2, 3, 4 - Human genome, chromosomes and cell division, how genetics cause disease Deck (111)
What 2 factors causes all disease?
Genetics and environment
In what direction is DNA always replicated and read?
5 to 3 direction
Bases in DNA?Bases in RNA?
DNA = ACGTRNA = ACGU
In DNA what bases pair?
Thymine and AdenineGuanine and Cytosine
In the nucleus, what is DNA wound around?
Proteins including histone proteins
What are genes?
Short sections of DNA - code for a specific protein by determining the order in which amino acids should be joined
What are chromosomes?
a thread-like structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
What are the 2 main phases of the ell cycle?
What happens during interphase?
The cell grows, accumulating nutrients needed for mitosis and duplicating DNA
What are the parts of interphase?
G1 - the cell makes new proteins for DNA synthesisG0 - the cell carries out its normal activitiesSynthesis - the cell replicates its DNAG2 - the cell prepares to divide
What happens during the mitotic phase?
The cell splits itself into 2 distinct cells (daughter cells)- genetically identical
What are the checkpoints in the cell cycle and what does each check?
G1 checkpoint = is the cell big enough and the environment suitable (if not, goes to G0)G2 checkpoint = has the DNA replicated, is the cell big enough, and the environment suitable?Mitosis checkpoint = are the chromosomes aligned on the spindle?
How many pairs of chromosomes does the normal human have?
What type of DNA damage can occur during replication? (3)What conditions mean that you cannot repair these damages?
DNA strand breaks (BRCA1/2)Chemical cross linking (Xeroderma pigmentosa)Mismatched base (hereditary colorectal cancer)
What happens during mitosis?
1 diploid parent cell becomes 2 identical diploid daughter cells
What happens during Meiosis?
a diploid cell, ordinarily having two complete sets of chromosomes, gives rise to 4 haploid cells (gametes) each having one set of genetically different chromosomes (germ cell forms either 4 sperm or 4 egg cells)
What are the stages in meiosis?
DNA replicates and recombines (crossing over occurs)Cell division 1Cell division 2
How are the chromosomes produced during meiosis genetically unique?
Due to crossing over
How is RNA different to DNA?
Single strandedRibose is backbone instead of deoxyriboseUracil is used instead of thymine
What parts of DNA are spliced out after transcription?
What is the amount of protein produced determined by? (4)
Rate of transcription (manufacture of pre-mRNA)Rate of splicing to mRNAHalf life of mRNARate of processing of polypeptide
What converts DNA to pre-mRNA?
What converted pre-mRNA to mRNA?
What converts mRNA to protein?
What do 3 bases encode?
1 amino acid or a stop
What is a polymorphism?
The occurrence of a chromosome or a genetic character in more than one form, resulting in existence of more than one morphological type in the same population (population frequency of greater than 1%) - variation in the human genome that does not cause a disease it its own right but may however predispose to a common disease
What is a single nucleotide polymorphism?
a DNA sequence variation occurring when a single nucleotide - A, T, C, or G - in the genome (or other shared sequence) differs between members of a species (or between paired chromosomes in an individual)
What is a mutation?
Disease causing genetic change
What does a mutation in FGFR3 cause?