Following statements are regarding to the role of the Disheveled and β-catenin proteins in specifying the cells of the sea urchin embryo.

A. During normal development, β-catenin accumulates predominantly in the micromeres and somewhat less in the veg2 tier cells.

B. In embryos treated with lithium chloride, β-catenin accumulates in the nuclei of all blastula cells and the cells of the animal pole become specified as ectoderm.

C. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are not specified, and the entire embryo develops as a ciliated ectodermal ball.

D. When β-catenin is prevented from entering the nuclei (i.e., it remains in the cytoplasm), the vegetal cell fates are specified, and the entire embryo specified as endoderm and mesoderm .

Which of the following statements are true?

#Question id: 10644

#Unit 10. Ecological Principles

There is a species with following feature Good colonizer, reach sexual maturity rapidly, Short-lived, low investment in care for the young

Which of the following above feature showing growth pattern and survival ship curve

#Question id: 10645

#Unit 10. Ecological Principles

The logistic equation above is used to describe the rate of change of a population, N, with time, t, where r is the intrinsic rate of increase and K is the carrying capacity. dn/dt is isoclines when 

#Question id: 10646

#Unit 10. Ecological Principles

Four sampling unit of Area occupy by species having following number is 00, 20, 10, 20. What is abundance of that species?

#Question id: 10647

#Unit 10. Ecological Principles

Use the graph to answer the following question

In the figure, which of the following survivorship curves implies that an animal may lay many eggs, of which a regular number die each year on a logarithmic scale?

#Question id: 10648

#Unit 10. Ecological Principles

Which statements about K are correct?

I) K varies among populations.

II) K varies in space.

III) K varies in time.

IV) K is constant for any given species.

#Question id: 10649

#Unit 10. Ecological Principles

According to the logistic growth equation

A) the number of individuals added per unit time is greatest when N is one fourth of K

B) the per capita growth rate (r) increases as N approaches K

C) population growth is zero when N equals K

D) the population grows exponentially when N approaches K