How much time does the average human need to sleep per day?

Why is it said that the earthworm has a closed circulatory system?

arrange the following lists in hierarchical order. leaf, molecule, atom, tree, plant cell, trunk system, leaf tissue.

The three-dimensional structure of a protein is determined by its primary, secondary, and tertiary structures. Define the primary, secondary, and tertiary structures. What are some of the common secondary structures?

The upper forelimbs of humans and bats have fairly similar skeletal structures. T/F

Explain a scenario in which primary succession would occur.

All living things are?

What characteristics do mutations have?

Primary succession is most likely caused by what?

Strawberry plants typically reproduce by making runners, which are miniature versions of themselves, that grow off of the roots and stems of the parent. This type of vegetative reproduction is known as A) pollination. B) fragmentation.

Is one body system more important than another system?