A population of birds has many small variation among the individuals in the population. Variation in beak size among these birds would affect their survival most if the

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction

wild parsnip is a perennial plant which reproduces rapidly in areas which have no sign of agricultural activity such roadside or at no tillage open areas. it's considered invasive because it can inhibit the growth of another plant  and its reproduction is fast. there are several harmful effects of this invasive plant although its taproot is edible since it is a member of the carrot family. wild parsnips can cause skin blistering when in contact because of the chemicals it contains, second it inhibits the growth of other plants, it will restrict the growth of animals when eaten and lastly, it drives away natural pollinators like bees.