In mammals, The placenta is essential to the embryo for:

A. Nutrition, reproduction, and growth
B. Nutrition, respiration, and excretion
C. Locomotion, respiration, and excretion
D. Nutrition, reproduction, and excretion

Which of the following statements is true? a. there are more chromosomes in an organism than there are genes. b. there are more genes in an organism that there are chemical bases. c. dna is made of sugar, phosphate, and carbon. d. genes are found in specific locations on a chromosome.

If assuming tasting ptc as a simple gene trait, what other genotype would you select to put in this missing genotype box that could result in this phenotype

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?