Explanation:
Metabolism in eukaryotic cells depends on the endoplasmic reticulum because it transports materials between membrane-bounded organelles within the cell.
Answer: The brainstem controls autonomic functions through cranial nerves arising from it, along with the medulla oblongata, therefore an injury to the area can cause loss of these functions.
Explanation:
The brainstem comprises of the midbrain, and the pons and medulla of the hindbrain. It is in direct continuation with the spinal cord. Ten cranial nerves arise from this part, and a number of tracts pass through this region. The medulla of the brainstem are particularly involved in maintaining heart rate, breathing and blood pressure. In case of a brainstem injury, the cranial nerves responsible for autonomic functions could get damaged leading to dysfunction and/or the areas of medulla consisting of centres controlling heart rate, blood pressure or other autonomic functions, if damaged could cause difficulties.
The brain is protected by the bones of the skull and by a covering of three thin membranes called meninges. The brain is also cushioned and protected by cerebrospinal fluid.
The question is about a test cross. Definition of a test cross: Generally a cross involving a homozygous recessive individual. When a single trait is being studies, a test cross is a cross between an individual with the dominant phenotype but of unknown genotype (homozygous or heterozygous) with a homozygous recessive individual. If the unknown is heterozygous, then approximately 50% of the offspring should display the recessive phenotype. If the individual is homozygous all the progeny will have the dominant phenotype. James' suggestion to use show the result of the two possible crosses with a Punnet square is a great suggestion.
