Birds' feet change slowly over time, depending on their habitat. Ptarmigans live in snowy areas and eat pine needles, twigs, and insects. Roadrunners live in deserts and plains and eat anything they can catch. Peregrine falcons live on high perches and use their talons for grasping their prey. Mallards live near water and swim and dive for food. What is an inherited behavior or physical change that helps an organism survive and reproduce in its environment?

A. adaptation
B. variation
C. evolution
D. species

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic