Chapter 1-Animals : Body Movements
Q1-Snakes have no legs.How do they move on land?
Ans-Snakes are reptiles with no legs. They move by using their muscles to push their scales against the ground or other objects.Snakes have four ways of moving around. Serpentine method, Concertina method, Sidewinding, Rectilinear Method.They are also exothermic.
Q2-What are invertebrates?Give some examples.
Ans-Invertebrates are animals that don’t have a backbone. The vertebral column is another name for the backbone. Over 90% of all species on Earth are invertebrates, and invertebrate species have been found in the fossil record as far back as 600 million
years ago. Molecular biology studies suggest that all invertebrates evolved from a single invertebrate group.
Types of Invertebrates
Eighty-five percent of invertebrates – some 923,000 species – are arthropods. Mollusks have approximately 100,000 distinct
species. Some of the most common types of invertebrates are:
protozoans – single-celled organisms such as amoebas and paramecia
annelids – earthworms, leeches
echinoderms – starfish, sea urchins, sea cucumbers
mollusks – snails, octopi, squid, snails, clams
arthropods – insects, spiders, crustaceans such as shrimp, crabs, lobsters
Quiz
1. An invertebrate is/has ________________________.
A. warm-blooded.
B. a mammal.
C. a soft body.
D. a backbone.
Answer to Question #1
C is correct. Invertebrates have soft bodies because they have no internal skeleton.
2. Which of the following organisms is NOT an echinoderm?
A. spider
B. sea star
C. sea cucumber
D. sea urchin
Answer to Question #2
A is correct. Spiders are arthropods, not echinoderms.
3. What percentage of species on Earth are invertebrates?
A. 50%
B. over 90%
C. 75%
D. All species on Earth are invertebrates.
Answer to Question #3
B is correct. Over 90% of the species on Earth are invertebrates.
Q3-Give two diffrences between frog and a lizard.
Ans-
Examples of Amphibians-Toads, Frogs, Salamanders, etc.
Examples of Reptiles- Snake, Lizards, Crocodile, etc.
Q-What is the difference between a reptile and an amphibian?
Ans-Reptiles have skin covered with scales, breathe air through lungs, and lay hard-shelled eggs on land. Amphibians are
animals that can live on land or in water, and they are characterized by moist glandular skin, gills, and a lack of scales.
Examples of reptiles are: alligators, crocodiles, lizards, snakes, turtles, and tortoises.
Examples of amphibians are: frogs, toads, salamanders, and newts.
Q4-What are vertebrates?
Ans-The Animals with the back bone are called vertebrates which are additional split into smaller groups Insects, Amphibians,
Reptiles, Birds and Mammals.
Q5-How many legs do insect have?What sort of body covering do they have?
Ans-All insects have six legs (three pairs of jointed legs) and usually four wings (two pairs).Insects have exoskeletons (skeletons on the outside). Their skeletons are made out of thin, hard pieces or plates, like armour, made of chitin. All together, these pieces make a hard layer around the insect’s body. The exoskeleton protects the insect.The body of an insect has three main parts: a head, a thorax, and an abdomen. On the head are an insect’s compound eyes, its two antennae (they feel and smell things), and its mouth.On the thorax, insects have wings and legs. All insects have six legs (three
pairs of jointed legs) and usually four wings (two pairs).The abdomen is the back part of the insect. Inside the abdomen is the
stomach, the heart, and the excretory system where body wastes pass out of the insect. Bees also have a stinger at the back of the
abdomen.
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