What are CD4 cells? A. HIV treatment cells B. T cell helpers that are destroyed by HIV C. experimental AIDS vaccine D. Opportunistic cells that destroy the immune system

Which describes how weathering and erosion are different? weathering is caused by water. erosion is caused by wind and ice. erosion transports sediments. weathering is a natural process.

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy

What are the possible blood types among the children of parents that are ab and ii? oa) types a and b ob) types a, b, and ab c) types a, b, and o od) types a, b, ab, and o