Tundra:   Tundra is found at high latitudes, adjacent to ice margins, where insolation is low.  Tundra is the youngest of all biomes as it was formed after the retreat of glaciers 10000 years ago.  Lack of light and rainfall mean (25 cm per year) that rates of photosynthesis and productivity are low. Large part of the year, water can be locked away in permafrost, a layer of permanently frozen soil below 0.5–1 m.

TLS Online TPP Program

#Id: 1618

#Unit 4. Cell Communication and Cell Signaling

Chronic inflammation causes by IL-6, TNFα, IL-1β, IL-18.

TLS Online TPP Program

#Id: 6892

#Unit 3. Fundamental Processes

To modify DNA at a new position requires the action of a de novo methyltransferase, which recognizes DNA by virtue of a specific sequence. It acts only on unmethylated DNA to add a methyl group to one strand.

TLS Online TPP Program

#Id: 8950

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 1041

#Unit 5. Developmental Biology

The cells that make up the limb bud are derived from the 

1. posterior lateral plate mesoderm

2. adjacent somites

3. bud’s overlying ectoderm

TLS Online TPP Program

#Id: 7786

#Unit 2. Cellular Organization

NLSs were first discovered through the analysis of mutations of the gene for large T-antigen encoded by simian virus 40 (SV40).