1. Dolphins are highly intelligent marine mammals and are part of the family of toothed whales that include
Orcas and pilot whales. They are found worldwide, mostly in shallow seas of the continental shelves, and
are carnivores, mostly eating fish and squid. Dolphin coloration varies, but they are generally grey in color
with darker backs than the rest of their bodies. Dolphins consume a variety of prey including fish, squid
and crustaceans.It is difficult to estimate population numbers since there are many different species spanning a large
geographic area.
2. Like bats, dolphins use echolocation to navigate and hunt, bouncing high pitched sounds off objects,
and listening for the echoes. Most species live in shallow areas of tropical and temperate oceans
throughout the world. Five species live in the world’s rivers.
3. Dolphins are well-known for their agility and playful behaviour, making them a favourite of wildlife
watchers. Many species will leap out of the water, spy-hop (rise vertically out of the water to view their
surroundings) and follow ships, often synchronizing their movements with one another. Scientists believe
that dolphins conserve energy by swimming alongside ships, a practice known as bow-riding.
4. Dolphins live in social groups of five to several hundred. They use echolocation to find prey and often
hunt together by surrounding a school of fish, trapping them and taking turns swimming through the
school and catching fish. Dolphins will also follow seabirds, other whales and fishing boats to feed
opportunistically on the fish they scare up or discard.
5. To prevent drowning while sleeping only half of the dolphin’s brain goes to sleep while the other half
remains awake so they can continue to breathe.
6. Dolphins reproduce their kin throughout the year, although in some areas there is a peak in spring and
fall. The gestation period is 9 to 17 months depending on the species. When it is time to give birth, the
female will distance herself from the pod, often going near the surface of the water. The number of
offspring is usually one; twins are rare. As soon as the offspring is born, the mother must quickly take it to
the surface so that it can take its first breath.
The baby dolphin will nurse from 11 months to 2 years, and after it is done nursing, it will still stay with its
mother until it is between 3 and 8 years old.
(i) What kind of food do dolphins consume?
a) Fish b) Squid c) Crustaceans d) All of the these
(ii)Dolphins use _______ to find prey:
a) Echolocation b) Isolation c) Navigation d) Attraction
(iii) Dolphins are mostly found in
(a) deep seas (b) shallow seas
(c) all kinds of seas (d) deep rivers
(iv)Dolphins swim alongside ships
(a) to conserve energy (b) to help ships sail faster
(c) in search of their prey (d) to attack their prey
(v) They use echolocation to
(a) find ships in the sea (b) be with their group
(c) enjoy themselves (d) find prey for themselves
(vi)The dolphin’s brain remains half active while sleeping to:
(a) look at its surroundings (b) save itself from ships
(c) prevent drowning (d) find its prey
(vii) The word ‘agility’ used in paragraph 3 means the same as
(a) slow moving (b) perfection
(c) quickness (d) gracefulness
(viii) The word ‘distance’ used in paragraph 6 means the same as:
(a) near (b) withdraw (c) interval (d) aloofness
(ix) Dolphins are well known for their—
(a)Agility (b) playful behavior (c) laziness (d) both a & b
Answers
Answer:
1. Dolphins are highly intelligent marine mammals and are part of the family of toothed whales that include
Orcas and pilot whales. They are found worldwide, mostly in shallow seas of the continental shelves, and
are carnivores, mostly eating fish and squid. Dolphin coloration varies, but they are generally grey in color
with darker backs than the rest of their bodies. Dolphins consume a variety of prey including fish, squid
and crustaceans.It is difficult to estimate population numbers since there are many different species spanning a large
geographic area.
2. Like bats, dolphins use echolocation to navigate and hunt, bouncing high pitched sounds off objects,
and listening for the echoes. Most species live in shallow areas of tropical and temperate oceans
throughout the world. Five species live in the world’s rivers.
3. Dolphins are well-known for their agility and playful behaviour, making them a favourite of wildlife
watchers. Many species will leap out of the water, spy-hop (rise vertically out of the water to view their
surroundings) and follow ships, often synchronizing their movements with one another. Scientists believe
that dolphins conserve energy by swimming alongside ships, a practice known as bow-riding.
4. Dolphins live in social groups of five to several hundred. They use echolocation to find prey and often
hunt together by surrounding a school of fish, trapping them and taking turns swimming through the
school and catching fish. Dolphins will also follow seabirds, other whales and fishing boats to feed
opportunistically on the fish they scare up or discard.
5. To prevent drowning while sleeping only half of the dolphin’s brain goes to sleep while the other half
remains awake so they can continue to breathe.
6. Dolphins reproduce their kin throughout the year, although in some areas there is a peak in spring and
fall. The gestation period is 9 to 17 months depending on the species. When it is time to give birth, the
female will distance herself from the pod, often going near the surface of the water. The number of
offspring is usually one; twins are rare. As soon as the offspring is born, the mother must quickly take it to
the surface so that it can take its first breath.
The baby dolphin will nurse from 11 months to 2 years, and after it is done nursing, it will still stay with its
mother until it is between 3 and 8 years old.
(i) What kind of food do dolphins consume?
a) Fish b) Squid c) Crustaceans d) All of the these
(ii)Dolphins use _______ to find prey:
a) Echolocation b) Isolation c) Navigation d) Attraction
(iii) Dolphins are mostly found in
(a) deep seas (b) shallow seas
(c) all kinds of seas (d) deep rivers
(iv)Dolphins swim alongside ships
(a) to conserve energy (b) to help ships sail faster
(c) in search of their prey (d) to attack their prey
(v) They use echolocation to
(a) find ships in the sea (b) be with their group
(c) enjoy themselves (d) find prey for themselves
(vi)The dolphin’s brain remains half active while sleeping to:
(a) look at its surroundings (b) save itself from ships
(c) prevent drowning (d) find its prey
(vii) The word ‘agility’ used in paragraph 3 means the same as
(a) slow moving (b) perfection
(c) quickness (d) gracefulness
(viii) The word ‘distance’ used in paragraph 6 means the same as:
(a) near (b) withdraw (c) interval (d) aloofness
(ix) Dolphins are well known for their—
(a)Agility (b) playful behavior (c) laziness (d) both a & b
Answer:
The correct answers are- i.- d, ii.-a, iii.- b, iv- a, v-d, vi-c, vii.- c, viii.- b,ix.- d
Explanation:
i. Dolphins are carnivores, thus they prefer eating squid and fish. Apart from that they also eat Crustaceans. So the correct answer is d. all of these.
ii. a. Dolphins use Echolocation for hunting prey. It basically bounces high-pitched sounds through the preys.
iii. b. Dolphins prefer living in Shallow seas (most of them prefer).
iv. a. Dolphins swim alongside the ships to conserve energy. It is commonly known as bow-riding.
v. d. to find the prey they use Echolocation that uses high pitched sound.
vi. c. to prevent from drowning their half brain is active, it helps them breathe.
vii. c. quickness
viii. b. withdraw
ix. d. both a and b
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