How do the physical and chemical properties of the element change?

A. within a group

B. across each period

C. within a family

D. across each group

A scientist tries to mate the two similar-looking fruit flies Drosophila melanogaster and Drosophila simulans. He finds that they are unable to produce viable offspring. What kind of evolutionary barrier could this be? A. Chromosomal B.

Select the correct answer from each drop-down menu. This map shows the level of water stress in different regions of United States. Region is most prone to water scarcity caused by rises in population.

Parthenogenesis is a type of reproduction that does not require a mate. It's rarely seen in birds and higher vertebrates. Parthenogenesis involves the formation of a zygote. But this zygote is formed without fertilization.

Which of the following groups includes members of both the plant and animal kingdom? A Viruses B Fungi C Bacteria D Parasite

Explain why cellular respiration is more efficient when oxygen is present in cells.

When a protein is denatured, why does it lose its functionality?

This is a rotating machine that converts the kinetic energy of the wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a grinding stone, the machine is usually called a windmill.

In what way are slime molds similar to kelp?

What does not exist in a supersaturated solution

When dust and ash particles from a volcanic eruption block out sunlight and reduce solar radiation, earth experiences the. This results in temporary climate cooling