Question

1. Hummingbird can hover because

A. they have the large breast muscles that enable their wings to generate lift in the upstroke and downstroke

B. They burn only sugar and not fat

C. Their wings beat rapidly, often higher than 30 beats per sec.

D. A and C

2. Salmon do not feed during migration, they totally rely on their energy reserves. The advantage of not feeding on route is ______. (1 sentence explanation please)

Answer 1

1)Option A is the correct Answer-they have the large breast muscles that enable their wings to generate lift in the upstroke and downstroke

Reason:Humming bird can remain in one position (Hover) because it have a large breast msucle (pectorslis major) which bind in the underneath and the humerous which help the humming bird to produce a good upstroke force to lift the Wing .

Most of the normal bird doesnot have enough space to accomodate the muscle , so they dont have musch upstroke force.

The wing beat rapidly in humming bird at a rate of 70 per second.

2)The salmon fish doesnot eat feed when they are in fresh water , they depend upon the energy reserves.

they only feed from the ocean when they are going for spawning