Answer:
beriberi,scurvy,pellagra,night blindness,pernicious anaemia,lack of blood clothing & etc
The answer is density-independent. Hope this helps!
All evolutionary changes that allow a species to change in response to the environment, are originally a result of beneficial DNA mutations.
Beneficial genetic (DNA) mutations are result in individuals with special characteristics that allow them to survive better in the environment so they pass their genes to the next generation.
Here's a fictional example I made just for you!: Lets say you have an alien species called Hibas. They are jelly blobs that float around, don't move, and open their mouths to capture neon shrimps that happen to swim into their mouths. But one day a certain Hiba developed some muscles through a genetic mutation. It was able to "wiggle" through the water and steer itself instead of floating around. This allowed it to eat more neon shrimp than the other Hibas, so it grew faster and was able to reproduce faster. It's kids also had muscles and had an advantage so they reproduced faster then the other Hibas. Eventually the whole Hiba species started to have muscles because the ones that didn't weren't able to compete and did not survive as well.
The reason that most of the Hibas developed muscles was because one of them had a mutation that allowed it to have muscles. This was a BENEFICIAL mutation that allowed it to SURVIVE BETTER.
Answer:
The phenotypic ratio will be 3:1
Explanation:
As per this question there are two phenotypes for seed color, yellow and green. Both the parents are true breeding that means they are homozygous for this trait. Also, all the F1 plants have yellow seed color which clearly indicates that yellow seed color is a dominant trait while green is recessive trait.
The cross of true breeding plants as mentioned above is depicted as under:
Parents YY x yy
/ \ / \
F1 generation Yy Yy Yy Yy
So, as per the law of dominance because of the presence of Y allele, all these progeny will be yellow in color.
Next, when these F1 plants will be crossed, the result will be as under:
F1 generation Yy x Yy
/ \ / \
F2 generation YY Yy Yy yy
The genotypic ratio of F2 generation is 1:2:1
The phenotypic ratio of F2 generation is 3:1
It simply means that in F2 generation, 3 progeny which have allelic combination YY & Yy will be yellow colored while 1 progeny which has allelic combination yy will have green color.
Cell wall: it controls the movement of substances that come in and out of the cell
cell membrane: it strengthens the cell
similarities: both of the parts are around the circumference of the cell
