Directional selection favours:

(1) Both extremes of a trait

(2) Intermediate form of a trait

(3) Environmental differences

(4) One extreme form over the other extreme form and over intermediate forms of the trait

 

Given below is the representative evolutionary history of vertebrates through geological periods. A,B,C and D respectively are :

1. Dinosaurs, Thecodonts, Therapsids and Pelycosaurs

2. Dinosaurs, Therapsids, Thecodonts and Pelycosaurs

3. Pelycosaurs, Therapsids, Thecodonts and Dinosaurs

4. Therapsids, Dinosaurs, Pelycosaurs and Thecodonts

Karn & Penrose showed that birth weight follows a normal distribution, that mortality for newborns is greater for those either under-or over-weight, and that the mean birth weight (7 lbs) coincides with that showing minimum mortality. The type of natural selection operating here is shown by the graph :

1. (a)

2. (b)

3. (c)

4. Both (a) and (b)

The following two plants exhibit :

1. Analogous organs

2. Vestigial organs

3. Rudimentary organs

4. Homologous organs

In the apparatus of Urey and Miller experiment the gases [G] contained in the flask are :

1. Methane, Carbon dioxide, Ammonia and Water vapour

2. Methane, Hydrogen cyanide, Ammonia and Water vapour

3. Methane, Ammonia, Hydrogen and Water vapour

4. Carbon dioxide, Oxygen, hydrogen and ammonia 

Why is it said that looking at stars on a clear night sky means looking back in time?
A. What we are seeing at that time is actually what started its journey millions of years back
B. What we are seeing at that time is actually what started its journey trillions of days back
C. What we are seeing at that time is actually what started its journey thousands of days back
D. What we are seeing at that time is actually what started its journey thousands of kilometres away

Which of the following statements are not true?

Big Bang theory attempts to explain

Which of the following is not true about Big Bang theory?

Which of the following is true regarding early earth?

1. Earth was supposed to have been formed about 4.5 billion years back.

2. The atmosphere of early earth was full of water vapour.

3. The surface of earth was covered by water vapour, methane and carbondioxide, the three compounds, formed from molten mass.

4. The UV rays from the sun broke up water into hydrogen and oxygen and lighter oxygen escaped.