Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation  and  on  egg-to-adult survival.  From  a  large  source  population, they  randomly  assigned  eggs  to  three experimental  populations  of  size  N,  equal  to  20,  60,  and0100.  For  later  generations,  they  collected  N  eggs  from each  population  and  moved  them  into  identical  vials  that  co0ntained  f2re0sh  me4d0ium.  Th6e0y  coun8te0d  the  number  of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by  scoring  alleles  at  several  polymorphic  loci  and  expressed  as  the  average  number  of  alleles  at  those  loci.  The results are summarized in Figure 1 and Figure 2 below.

The numbers of adult flies that emerged from the three populations in the first generation are closest to which of the following?

#Question id: 11401

#Unit 9. Diversity of Life Forms

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leafʹs nonliving, waxy covering, while inhibiting the growth of

other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, it causes a fatal disease in the plant. Once the plant dies, the bacterium

and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here? Use only those that

apply.

1.  nutrient recycler          2.  mutualist            3.  commensal              4.  parasite          5.  primary producer

#Question id: 11402

#Unit 9. Diversity of Life Forms

How can prokaryotes be considered to be more successful on Earth than humans?

#Question id: 11403

#Unit 10. Ecological Principles

Several categories of risk of species extinction have been defined. A species can be determined as critical endangered if there is considered to be

#Question id: 11404

#Unit 10. Ecological Principles

You were discovered 4 species in forest, their characteristic as following,

A specie eat only bamboo;

B species eat fruits of many tree species;

C species Short life span;

D species low population variability .

Which of the following species characteristics have been proposed as more prone to extinct?

#Question id: 11405

#Unit 10. Ecological Principles

Vulnerability to extinction can be linked to species following characteristics. Which of the following statement are correct?

A. Endemism species are more prone to extinction than fragmented

B. Species that are capable of migrating between fragments of habitat, such as between mainland areas and islands, may be more resistant to extinction

C. Population variability species are less prone to extinct

D. Species with naturally long life spans may be more likely to become extinct

#Question id: 11406

#Unit 10. Ecological Principles

Which of the following is true for a critically endangered species?