Van Valen law- he found a surprising result: rather straight curves, implying that the probability of extinction is roughly constant.

TLS Online TPP Program

#Id: 8395

#XL - Q Biochemistry

Sarcomere

Within each skeletal muscle cell are many myofibrils consisting of a repeating array of a specialized structure

TLS Online TPP Program

#Id: 5515

#XL - T Zoology

Natality means production of new individuals (offspring). 

Maximum or Absolute natality - maximum offspring produced under most suitable environmental conditions. 

Ecological natality - refers to number of offspring produced under prevailing environmental conditions.

TLS Online TPP Program

#Id: 8930

#XL - T Zoology

If the DNA damage is severe, p21 can cause the cells to senesce or p53 can induce apoptosis.

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#Id: 8000

#XL - T Zoology

No two different species can share the same niche but can have similar niches,  this is because of competition for resources like food, space etc

Two species cannot coexist permanently in a community if their niches are  identical

TLS Online TPP Program

#Id: 9389

#XL - T Zoology

Male stickleback fish develop red colour on their ventral side in the breeding season and maintain territories. 

When a conspecific male intruder enters their territory, resident males perform an aggressive display. 

The ethologist Niko Tinbergen presented models of different shapes to territorial male stickleback fish. He found that models of any shape elicited aggressive displays, provided the ventral part of the models was coloured red.