The answer would be D. variation
Answer:
B. Directional selection
Explanation:
When natural selection starts to choose one phenotypes that is an extreme (as in, a really small neck or a really long neck), this is an example of <u>directional selection.</u> It makes sense for giraffes to have evolved this way, because the longer the neck, the more ably they can eat food from high branches. The more food they could get, the more chance of reproduction, the more "evolutionarily fit" they are.
Stabilizing selection is when national selection picks average phenotypes (like a medium-sized neck). Disruptive selection is when the extremes are both picked (like all the medium-sized neck giraffes die, and two different species start to emerge). Sexual selection is picking a mate based on traits. Clearly, those answers don't work here.
Chorionic Villus Sampling. Definition: CVS is a test where the doctor collects a tiny piece of the placenta, called chorionic villus, which is then tested to check for chromosomal or genetic disorders in the baby.
1 Blue and yellow: 1 yellow
Let us assign the allele for Blue dragon color as B and that of Yellow dragon color as Y and create the punnet square below;
The phenotypic ratio will, therefore, be;
1 Yellow/Blue : 1 Yellow
Answer: 3. gravitropism
The movement of plants in response to stimuli is called as tropism. Plants respond to different stimuli like light (phototropism), water present in the soil (hydrotropism), gravity (gravitropism) and touch (thigmotropism).
Gravitropism refers the growth and movement of plant parts with respect to the force of gravity exerted by earth. The roots shows positive gravitational tropism because they are growing towards earth gravity. The shoots or stems shows negative gravitational tropism because they are moving or growing against the gravity.