All cells are surrounded by a membrane.

Which sentence states a characteristic of a cell membrane?

1) It is rigid.

2) It is semipermeable.

3) It is weak.

4) It is square.

In which parasite do all stages of the life cycle (including the hatching of its eggs) occur on the hide of the host animal? A. heartworm B. roundworm C. lice D. hookworm

The first organisms evolved on Earth around 4 billion years ago. The fossil record indicates that the first organisms were which of the following?

What is atp and what is its role in the cell?

If an individual allele has more than one effect on the phenotype, this is called

How many different species are marsupials?

Which of Mendel's laws BEST explains why genetic variations occur in offspring resulting from sexual reproduction? A law of segregation B law of dominance C law of independent assortment D law of crossing-over

When can a primary succession occur?

Friction between a skateboard wheel and the surface produces?

What are two functions of the cell membrane

Why can eukaryotes carry out more specialized functions than prokaryotes can? A) eukaryotes have more organelles B) Prokaryotes have more organelles C) eukaryotes are bigger D) prokaryotes are bigger