a. Giải thích tại sao động mạch của người không có van nhưng tĩnh mạch lại có van, giải thích tại sao?

Which of the following is a cost of urbanization? a-cities can provide a high standard of living. b-cities are hubs of entertainment and education. c-paving over land changes the environment. d-job opportunities are greater in urban centers.

Agroup of plant cells was exposed to radiation, which damaged the chloroplasts and caused them to lose function. if the mitochondria were unharmed, what would happen to the overall function of the plant cells? a. the cells would not be able to make food, but would be able to release energy from biomolecules. b. the cells would not be able to replicate dna, but would be able to break down waste. c. the cells would not be able to break down waste, but would be able to replicate dna. d. the cells would not be able to release energy from biomolecules, but would be able to make food.

Match the following items 1. rr 2. rr 3. identical alleles 4. unlike alleles 5. rr ()homozygous, recessive ()homozygous definition ()heterozygous, dominant cell ()heterozygous definition () homozygous, dominant cell