Endocasts of Homo erectus (left) and Homo sapiens (right) illustrate rapid increase in brain size. As early humans faced new environmental challenges and evolved bigger bodies, they evolved larger and more complex brains. Large, complex brains can process and store a lot of information.
Dad: TtBb
Mom: ttbb
You have to use distribution for dihybrid crosses. Meaning, the first allele of each trait has a equal chance of being paired with the other allele of the other trait. So for example with Dad, I will number the traits:
T(1)t(2)B(3)b(4)
To set up the possibilities from Dad, it would be 13, 14, 23, 24: TB, Tb, tB, tb. Same idea goes for Mom, except since all alleles are the same, you only need to make one column for Mom, since if you did all 4, the other 3 would just be repeats of the 1.
Cross:
tb
TB TtBb
Tb Ttbb
tB ttBb
tb ttbb
The phenotypic ratio is 1 Tall Brown: 1 Tall Blue: 1 Short Brown: 1 Short Blue
Answer:
The Laura tried to grow micro-organisms in culture broth medium in Petri-plates but the microbial growth was not observed even on the fourth day of culture which could be due to:
1. Laura could have not provided the correct broth medium maintaining the with pH and salt concentrations.
2. Microorganisms did not get optimal growth conditions.
3. The bacterial source could have died after the collection which could have lysed after their death and thus no longer visible.
Thin coat , becaus eit protects from temperature
