Answer:
25%
Explanation:
We have 2 independent genes with 2 alleles each: L/l and W/w
- W_: whiskers
- ww: no whiskers
- L_: long whiskers
- ll: short wiskers
Individuals with short whiskers will have the genotype <em>WWll </em>or <em>Wwll</em>.
<u>A cross between a rat heterozygous for both genes and a homozygous recessive rat is done:</u>
<h3>WwLl x wwll</h3>
-The homozygous rat will produce only <em>wl </em>gametes.
-The heterozygous rat will produce the following gametes: <em>WL</em>, <em>Wl</em>, <em>wL</em>, <em>wl</em>.
If you do a Punnett Square, you'll get that 25% of the offspring will be WwLl and will have short whiskers.
Genes and the environment can affect an organisms traits
A, plant growth would decrease. Decomposers break down organic materials into nutrients and return these nutrients to the soil. The nutrients are vital to plant growth. If decomposers went extinct, then eventually plants would use up all the existing nutrients and start to die.
after the evolution of the first living cells, fermentation wasn't needed, because aerobic respiration was now doable, since there was more oxygen in the air now. also, as the temperature increases, it becomes more energy consuming to conduct fermentation over aerobic respiration.
Hope this helps :)