Choose all of the characteristics of a T cell. i. Progeny include memory cells Is directly responsible for attacking foreign cells or virus-infected cells
ii. Forms clones upon stimulation
iii. Produces antibodies that are released to fluids
iv. Bears a cell-surface receptor capable of recognizing a specific antigen
v. Accounts for most of the lymphocytes in the circulation
vi. Progeny are plasma cells
vii. Progeny include regulatory, helper, and cytotoxic cells
viii. Originates in bone marrow from stem cells called hemocytoblasts and matures in thymus

After reading the paragraph below, answer the questions that follow. researchers have created a robot that has a very thin leg that is moved by cardiac (heart) cells contracting in unison. the robot, made of a polymer similar to that used in making contact lenses, is bathed in heart cells with supporting cells, which then attach to the robot and provide movement as they contract. all of the cardiac cells working together can cause the robot leg to move in a way that individual cells could not. this is an example of a. emergent properties of cells. b. energy flow through an ecosystem. c. adaptation. d. internal environment regulation.

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.