Aperson with trisomy 21 has an extra copy of chromosome 21. what happened during meiosis that caused the person to get three copies of chromosome 21 instead of two copies? a) nondisjunction b) genetic recombination c) crossing-over d) binary fission

92 sathe best for the question 11. most animals and plants reproduce sexually. this means that dna is passed down to new organisms from two parental organisms. which of the following is a key advantage of sexual reproduction?

What are the seven economic and social goals?

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one