You are on a research expedition to China and discover a previously unknown organism bearing closest
resemblance to amspecies of deer known as the Indian muntjac.
3 chromosome pairs 23 Chromosome pairs
Indian muntja Your organism
You tentatively think you have identified a close relative to the Indian muntjac. However, when you
karyotype each organism, you find the Indian muntjac has 3 chromosme pairs and your organism has
A. Your organism is likely to have more genes
B. Your organism is likely to have more complex phenotypes
C. All of the above
D. None of the above
3 chromosome pairs 23 chromosome pairs
Indian muntjac Your organism
You can make no firm predictions about gene content of the genomes from the karyotype
Does a larger genome mean more genes?
- no: human genome has 3.4 billion base pairs
- worm: 100 million base pairs
- BUT number of genes in human and worm: both ~20thousand genes
Does a more “complex” organism have more genes?
- more complex than worm, still have about same genes
- drosphila fly: only has 14 thousand genes vs worm w/ 20thousand genes
- would think fly more complex but has less genes
- however one gene in drosophila that can be alternatively spliced into 35 thousand different Mitosis in Mitosis in Meiosis
diploid cell haploid cell
Meiosis: makes haploid cells, don't need to do meiosis in haploid (can't reduce 1N) What is going on at the molecular level during the formation of sister chromatids?
DNAmolecules replicate to form identical chromatids