Question

1- The best time to collect plant specimens to analyze the biodiversity of an area is

a.   any time
b.   once, at the beginning of the growing season
c.   at two or three times during the entire growing season
d.   once, at the end of the growing season

2-Vascular tissue is composed of cells

a.   specialized in transporting water and other substances throughout the plant
b.   that pump fluids from one area to another
c.   responsible for ensuring water does not cross cell membranes
d.   both a and b

3-

A cell type in the phloem that lacks nuclei, mitochondria, or vacuoles, and has large pores through the cells walls at either end, is called a

a.   xylem   c.   sieve-tube element
b.   sieve tube   d.   companion cell

Answer 1

1- The best time to collect plant specimens to analyze the biodiversity of an area is

ans- c.   at two or three times during the entire growing season

I think this option is correct because the biodiversity of an area can't be examined at a single time. Plants vary in their growth & germination according tot he season and time. So one can determine the biodiversity by collecting the specimens 2 or 3 times in a season for precise results.

2-Vascular tissue is composed of cells

ans- both a & b

a.   specialized in transporting water and other substances throughout the plant
b.   that pump fluids from one area to another

Xylem and Phloem are the vascular tissues which provide the water and other important substance to the plant body as well as the phloem cells helps in the transfer of food material in the form of fluid from one part of the plant to other.

3- A cell type in the phloem that lacks nuclei, mitochondria, or vacuoles, and has large pores through the cells walls at either end, is called a

ans- c.   sieve-tube element

Sieve Tube cells of phloem lack nucleus, mitochondria, or vacuoles, and has large pores through the cells walls at either end, is called a. They are the conduits of food (mostly sugar) transport. Seive tube is a series of sieve tube elements placed end to end to form a continuous tube.