The graph illustrates the activity level of three common digestive enzymes, across a range of pH values. Which enzyme is likely to be the most active in the acidic environment of the stomach?

A) pepsin
B) trypsin
C) amylase
D) pepsin and trypsin

In animals, stem cells are specific types of cells which are able to differentiate into many different types of cells due to the expression of certain genes. What is the name of the type of cells in higher plants which have the same type of function as stem cells?
A) vascular cells
B) sporophyte cells
C) gametophyte cells
D) meristematic cells

Following the nuclear reactor accidents in Japan in April, 2011, some people were exposed to high levels of radiation. Children born to these people in the future could have mutations if these mutations occurred in the parents’
A) sex cells.
B) skin cells.
C) brain cells.
D) internal organs.

Suppose a mother carries two recessive genes for freckles (rr) and a father carries one recessive gene for freckles and one dominant gene for clear facial skin (Rr). What is the likelihood that their first child will have freckles?
A) 1/2

B) 1/4

C) 3/4

D) 4/4

The cell membrane is selectively permeable. O2 diffuses across the phospholipid bilayer. K+ must cross the cell membrane using a membrane protein. Which property of the cell membrane prevents the diffusion of K+?
A) The membrane proteins are attracted to the charged ions.
B) Only very small particles are able to diffuse across the cell membrane.
C) The lipid tails are hydrophobic, repelling charged ions such as K+.
D) The phosphate heads are hydrophobic and prevent the passage of polar substances.

There's about 34ish question's and I just want to make sure I have the right answer's. Thank you! :)

2 answers

So what are your answers to each question then?
1.A
2.C
3.A
4.A
5.D