What causes the expression of a recessive trait?

A. two dominant factors

B. one dominant and one recessive factor

C. two recessive factors

D. one dominant gene

As far as Alzheimer's researchers know, the primary cause of Alzheimer's disease is: a. deterioration of neurons that produce the neurotransmitter acetylcholine. b. pruning or deterioration of unused neurons over the life span. c.

The fungus responsible for causing the disease called St. Anthony's fire is Histoplasma. ergot of rye. blight. Aspergillus.

During a trip to the Galapagos Islands, which observation led Charles Darwin to suspect that organisms change over time? Island finches were able to breed with mainland species.

How is phagocytosis related to endocytosis?

What is the effect of a mutation? no change to the DNA of the organism positive change to the organism negative change to the organism

Coal is used to produce energy. The harmful gases produced by coal are cleaned up by a method which needs a large amount of limestone. Predict and explain the long term effect on the environment of obtaining and using limestone.

True or false two genes may not segregate independently if they are on the same chromosmoe

Blood pressure rises and falls in a pattern corresponding to the phases of the

Immune system cells enter a resting phase after undergoing mitosis. when activated-for example, by an infection-they can reenter the sequence of events in the cell cycle that leads to cell division.

How does a muti-celluar organisms organise