When plants of a particular species are growing too close to each other, crowding may eventually lead to mortality, known as self-thinning. this type of mortality is density-dependent. oscillating. exponential. density-independent. random?

It should be planted from each other. So that plants can get more water s,sunlight and the needs to grow .

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)