How did mendel make crosses with his plants? a., he planted the seeds of each type together, and they grew into a single plant. b., he cut the peas in half and combined them to grow a single plant. c., he grew plants from seeds and fertilized the ovules of one plant with the pollen from another. d., he allowed the pea plants to intertwine during growth to allow fertilization.

What must happen before meiosis can begin? a. four gametes must be produced b. the four tetrads must be pulled apart c. dna doubles and produces sister chromatids d. the cell membrane pinches together

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

20 point pls brianliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?