The placenta 

A. conducts the mother's blood directly to the embryo.
B. is responsible for providing the nutritional needs of the embryo.
C. nourishes the egg while it is yet in the ovary.
D. is discharged from the body and rebuilt approximately every twenty-eight days.


B. is responsible for providing the nutritional needs of the embryo.

Biology & Microbiology

You might also like to view...

Describe the open-ocean planktonic food chain, and elaborate on why its supports few large animals

What will be an ideal response?

Biology & Microbiology

Yeast research with autonomously replicating sequences (ARS), along with digestion of chromatin with DNase I, have led scientists to determine that

A) DNA is not protected inside a nucleosome. B) ARSs are really plasmids. C) ARSs bond irreversibly to replication enzymes. D) origins of replication are accessible regions of DNA devoid of nucleosomes.

Biology & Microbiology

Endocrine and exocrine glands are derived from what type of tissue?

a. muscle b. nerve c. endocrine d. epithelial e. connective

Biology & Microbiology

Why do the same trans-regulatory elements lead to very different morphology in different species of organisms?

A. Different species have genetic codes that use different codons, leading to different amino acid sequences. B. Morphological change depends on sequence mutations in enhancers. C. These regulatory elements have no effect on morphology, only metabolism. D. The transcription factor activates different combinations of enhancers and downstream genes. E. The trans-regulatory elements in different lineages have independently evolved the same sequence, by convergent evolution.

Biology & Microbiology