CHROMOSOME STRUCTURE Flashcards
WHAT METHOD CAN BE USED TO SHOW THAT CHROMOSOMES CAN BE EASILY DISTINGUISHED AT METAPHASE OF MITOSIS.
CHROMOSOME PAINTING
WHAT IS A CHROMOSOME
A HIGHLY COILED FIBRE OF CHROMATIN
WHAT IS EUCHROMATIN
CHROMATIN IN ITS 10NM FIBRE FORM WRAPS AROUND HISTONE PROTEINS LIKE A BEAD ON A STRING
WHAT IS HETEROCHROMATIN
CHROMATIN IN ITS 30NM FIBRE FORM WRAP INTO NUCLEOSOME ARRAYS IN THEIR MOST COMPACT FORM
WHAT DOES HIGHER LEVEL DNA SUPERCOILING OF THE 30NM FIBRE PRODUCE
THE METAPHASE CHROMOSOME
WHAT IS A NUCLEOSOME MADE UP OF
- A SET OF PROTEINS CALLED A HISTONE OCTAMER (H2A,H2B,H3,H4)X2
- A LITTLE LESS THAN TWO TURNS OF DNA
WHAT IS THE FUNCTION OF THE NUCLEOSOME
CAN BE OPENED UP SO THE MACHINER FOR TRANSCRIPTION/REPAIR ETC CAN ACCESS DNA
HOW IS THE CHROMATIN STRUCTURE AND FUNCTION REGULATED BY THE NUCLEOSOME
THE N TERMINUS TAILS OF THE HISTONE PROTEINS INTERACT WITH OTHER PROTEINS FACILITATING REGULATION
THE HISTONE CAN BE ROLLED UP AND DOWN TO HIDE AND EXPOSE DNA FOR TRANSCRIPTION.
WHAT IS A LINKER HISTONE
LINKER HISTONES SUCH AS H1 STRAP TO DNA ON HISTONE OCTAMERS LIKE A CLIP TO LIMIT MOVEMENT OF DNA
(THIS IS A FEATURE OF HETEROCHROMATIN - TRANSCRIPTIONALLY SILENT CHROMATIN)
WHAT IS A FRACTAL GLOBULE
IN INTERPHASE CHROMATIN COMPRISES OF FRACTAL GLOBULES THAT CAN CONDENSE AND DECONDENSE WITHOUT BECOMING KNOTTED AND THEY ARE MOVED FROM ONE PART OF THE NUCLEUS TO ANOTHER
WHAT ACCOMPANIES TRANSCRIPTIONAL ACTIVATION OF A GENE
EUCHROMATIN IS PUSHED IN THE GLOBULAR DOMAINS TO THE CENTRE OF THE NUCLEUS
WHAT IS A TELOMERE
DNA SEQUENCE IN LINEAR CHROMOSOMES AT THE END TO MAINTAIN CHROMOSOMAL INTEGRITY
TTAAGGG COPIES
WHAT IS A REPLICATION ORIGIN
A DNA SEQUENCE WHERE REPLICATION IS INITIATED
WHAT IS A CENTROMERE
DNA SEQUENCES TO WHICH KINETOCHORE ASSEMBLE TO HELP CHROMOSOME SEPARATION
CONTAIN ALPHA SATELLITE REPEATS THAT REPEAT THEMSELVES
WHAT IS A KINETOCHORE
A PROTEIN COMPLEX THAT BINDS MICROTUBULES ON THE MITOTIC SPINDLE
WHAT IS CENPA
CENTROMERIC PROTEIN A
MAKES CONTACT BETWEEN THE CENTROMERE AND THE INNER PLANE
WHAT IS THE SHAPE OF THE KINETOCHORE IN YEAST
BASKET SHAPE LINKS A SINGLE NUCLEOSOME OF CENTROMERIC CHROMATIN TO A SINGLE MICROTUBULE
HOW MUCH OF THE EUKARYOTIC GENOME CODES FOR CELLULAR PROTEINS
APPROX 1.5%
WHAT IS INCLUDED WITHIN THE 50% OF DNA WITH UNIQUE CODING SEQUENCES
- PROTEIN CODING REGIONS
- INTRONS
- NON REPITITVE DNA THAT IS NEITHER CODONS OR INTRONS
WHAT IS THE FUNCTION OF NON REPITITVE DNA THAT IS NEITHER CODONS OR INTRONS
CIS REGULATORY IN FUNCTION IE ACTS ON THE GENES IT SITS WITH TO REGULATION TRANSCIPTION
THE MORE PROTEIN CODING GENES - THE MORE NON CODING REGULATORY DNA
50% OF THE GENOME IS MADE UP OF REPEATED SEQUENCES - WHAT DO THESE INCLUDE
- SIMPLE SEQUENCE REPEATS
- SEGMENTAL DUPLICATIONS
- TRANSPOSONS
WHAT ARE TRANSPOSONS
MOBILE GENETIC ELEMENTS THAT JUMP AROUND THE GENOME
WHAT ARE THE 3 TYPES OF TRANSPOSONS
- DNA TRANSPOSONS
- RETROVIRAL TRANSPOSONS
- NON RETROVIRAL POLYA TRASPOSONS
WHAT IS THE METHOD OF DNA TRANSPOSONS
- MOVE BY CUT AND PASTE MECHANISM
- USE OF TRANSPOSASE TO CUT FROM THE STRAND
- THE STRAND SELF REPAIRS
- THE CUT TRANSPOSOSOME INSERTS RANDOMLY ELSEWHERE
