Plastid Inheritance Flashcards
1
Q
Types of plant plastids
A
Chloroplast Chromoplast Gerontoplast Leucoplast Carotenoid
2
Q
Chromoplast
A
Pigment - orange colour
Via Storage of lots of carotenoids
3
Q
Gerontoplast
A
Controls dismantling photosynthetic apparatus
4
Q
Leucoplast
A
Non pigmented
Monoterpene synthesis
In photosynthetic tissue of plants e.g. roots, bulb, seed
5
Q
Carotenoids
A
Orange/yellow pigment to attract pollinators
6
Q
Describe plastid DNA structure
A
~120,000-170,000bp
Circular
7
Q
How many genes used for different processes in chloroplast dna
A
- 37 genes encoding tRNA molecules
- 4 genes encoding some of the subunits of the RNA polymerase
- A gene encoding the large subunit of the enzyme RUBISCO (RBcl - DNA barcoding gene)
- 9 genes for components of photosystems I and II
- 6 genes encoding parts of the chloroplast ATP synthase
- Genes for 19 of the 60 proteins used to construct the chloroplast ribosome
8
Q
Effects of crumpled leaf (crl) mutation in Arabidposis
A
- Deficiency of a chloroplast protein with developmental defects
- Cell cycle regulation is altered and meristematic cells enter differentiation prematurely
- Reduced plant height and early endoreduplication in the leaves
- Activation of stress-response genes and production of aplastic cells in several organs
9
Q
Describe plastid insertion into the cell
A
- prokaryote grows and develops folding to increase surface area
- folds pinch off creating endomembrane around nucleoid = eukaryote
- aerobic protobacterium enters eukaryote (as prey or parasite) and becomes endosymbiont
- aerobic ability benefits host cell = assimilation of protobacterium
10
Q
How is non-nuclear DNA inherited
A
High copy number = multiple copies of DNA due to many mitochondria and chloroplasts in cell
- often inherited uniparentally e.g. mtDNA from mother
- chloroplasts randomly serrated to daughter cells… separated by cleavage furrow
11
Q
Describe the work of Carl Correns
A
Investigated plastid inheritance w/ 4O’clock plant/marvel of Peru
- 3 colours = pure white, pure green, variegated
- female determinant of offspring
- pure colours produced pure offspring
- variegated could produce all possible outcomes = unpredictable ratios and
