What structure gives animal cells a defined structure?

a. cell membrane

b. cell wall

c. proteins

d. cortex

The "ozone hole" that causes concern among scientists and the public is a zone of ozone depletion in the

A man who has had a vasectomy can no longer ejaculate? True or False

If your mother and father both have green fingernails, which is caused by a recessive allele, the odds of your having only one allele for the disorder are a. 3/4. b. 1. c. 1/4. d. 0. e. 1/2.

Which organism is the secondary consumer in the following food chain Plant - Caterpillar - Lizard Snake O A. Lizard B. Plant O C. Snake D. Caterpillar O

Marcus is admitted to the hospital for a bone marrow stem cell transplant from his brother. What will happen after his brother's stem cells are transplanted into Marcus?

An elephant has 56 chromosomes. Which statement about a zygote of an elephant is true?

Why when you rub a balloon on a piece of fabric or carpeting and then hold it against your head, your hair can stand up?

Which of the following statements is not true? Essential nutrients can be synthesized by the body. Vitamins are required in small quantities for bodily function.

Trees have active transport, why?

The question is how many chromosomes are in the sperm cells, and how many chromosomes will it's zygote have.