3) Plants have developed many methods of seed dispersal. The table below shows seeds of two different plants
Plant Mass of Seed (9) Seed Shape
Milkweed
0.00588
Dandelion
0.0026
How has the seed dispersal method developed by these plants given them a reproductive advantage?
A. The method ensures that offspring will be dispersed and reduces competition for resources.
B. The method reduces the chance that herbivores will consume the seeds.
C. The method lengthens the life cycle of each of these plants.
D. The method reduces the plants' need for water and other nutrients.
7D (S)
39

Astructure that is found in a plant cell and not in an animal cell is a ? central vacuole mitochondrion nucleus ribosome

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i. e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

What controls activities within a eukaryotic cell?