What is a blastocyst

A. a sperm fused with an egg

B. a structure that nourishes the fetus

C. a ball of about 100 cells

D. an unfertilized egg

What three particles make up atoms?

Imogene comes in contact with a specific pathogen. Her lymphocytes recognize the pathogen and start producing antibodies. What type of immunity is being described? acquired immunity innate immunity inflammation complement system

When does resperation take place

In a survivably cold environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm

How can farmers keep topsoil on their land? check all that apply. a. close their gates b. keep plants growing c. plant trees to shield fields from the wind d. do not plow when extremely heavy rains are expected?

What are the rocks in the rock cycle?

What's the most common type of mutation, and what impact does it have on natural selection?

How does convergent evolution works

Jim, who was 60, couldn't understand why he kept slowly gaining weight. he wasn't eating any more than usual, and he maintained his regular exercise routine. what explains his weight gain?

Who was the first to attempt scientific classification of the organisms on earth