How have conditions for life on Earth changed over time?

a.

separation of continents

c.

both a and b

b.

ice age

d.

neither a nor b

Which is produced when an egg and a sperm unite during a plant's life cycle?

Lisa is a healthy young woman whose energy requirement is 2250 kcal/day. based on this information, what would be her daily energy requirement during her first trimester of pregnancy

Largest to smallest structure Cell, Organ, organ system, tissue

When one air mass meets a different air mass, this meeting place between air masses is called a what?

Which organ is part of both the respiratory and digestive systems?

Which sentence correctly uses a pronoun in the nominative case as a subject? a. Stefani and me stretch for thirty minutes prior to our vaulting competition. b. Prior to our vaulting competition, Stefani and I stretch for thirty minutes. c.

Why can the same earthquake have different ratings on the Richter Scale and the Moment Magnitude Scale?

Which of the statements best describes the process of crossing over during meiosis? Haploid daughter cells trade chromosomes in pairs. Homologous chromosomes pair up and exchange segments of DNA.

A marine clam is mistakenly added to a freshwater aquarium. What will happen to the clam and why? Popcorn sold at movie theaters is very salty, causing people to become thirsty and to buy so drinks. Explain why salty popcorn causes this thirst.

What is the function of reproductive system?