Genome Size evolution

Question 1

genome size variation

Answer 1

vertebrates= larger genome size

• large variation in flowering plants
• mammals, short variation larger genome size than birds etc
• birds, very sort variation size–flight?
• reptiles, more variation than birds and mammals but still small
• teleost fish, medium/short range, size smaller than others
• protozoa, very large range due to very diverse group

Question 2

how can genome size change during evolution of single genus

Answer 2

large variation within species– correlation between number of retrotransposons and gene size

Question 3

Factors that increase genome size

Answer 3

1. Amplification of transposons
   - especially retrotransposons
2. polyploidy (recent)
   - if paleopolyploidy can also have decrease due to gene loss
3. expansion of non-coding regions
4. large segmental duplications

Question 4

factors that decrease genome size

Answer 4

1. recombination processes that eliminate DNA
   - btw repeats
   - btw transposons
2. more deletions relative to insertions

Question 5

Effects of genome size

Answer 5

variation in distance btw genes and gene density

• due to TEs
• can vary in regions of chromosome and btw species

Question 6

cellular effects of genome size increases

Answer 6

nucleus size
cell size
duration of cell cycle
cell differentiation rate

Question 7

DRAW intra/interelement unequal recombination

Answer 7

DRAW