Only 22 tRNAs are required for mitochondrial protein synthesis. The normal codon–anticodon pairing rules are relaxed in mitochondria, so that many tRNA molecules recognize any one of the four nucleotides in the third (wobble) position, allowing four codons to be recognized by a single tRNA.

TLS Online TPP Program

#Id: 7899

#XL - Q Biochemistry

Only 22 tRNAs are required for mitochondrial protein synthesis. The normal codon–anticodon pairing rules are relaxed in mitochondria, so that many tRNA molecules recognize any one of the four nucleotides in the third (wobble) position, allowing four codons to be recognized by a single tRNA.

TLS Online TPP Program

#Id: 8435

#XL - T Zoology

r-selected species

High rate of per capita population growth

poor  competitive ability

Grows quickly 

age early, 

devoting much energy to producing  large number of progeny 

Small in size, and individuals do not live long. 

Random matting

TLS Online TPP Program

#Id: 8436

#XL - T Zoology

Grime’s triangle

TLS Online TPP Program

#Id: 8437

#XL - T Zoology

TLS Online TPP Program

#Id: 8438

#XL - T Zoology

Where conditions for plant growth are less stressful, plants can evolve life history traits that fall along a continuum from competitors to ruderals.

TLS Online TPP Program

#Id: 8439

#XL - T Zoology

Without the abiotic stressors and without frequent disturbances, plants can grow rapidly for long periods of time, and this creates more competition among plants for soil nutrients and light.

Competitors also tend to grow to larger sizes and exhibit long life spans.

TLS Online TPP Program

#Id: 8440

#XL - T Zoology

Source–sink metapopulation model - A population model that builds on the basic metapopulation model and accounts for the fact that not all patches of suitable habitat are of equal quality.