Unit 1- Characteristics and classification of living organisms

Question 1

What is nutrition?

Answer 1

Nutrition is the taking in of materials for energy, growth, and development.

Question 2

What is movement?

Answer 2

Movement is an action by an organism or part of an organism causing a change of position or place.

Question 3

What is respiration?

Answer 3

Respiration is the chemical reaction in cells that breaks down nutrient molecules and releases energy for metabolism.

Question 4

What is reproduction?

Answer 4

Reproduction is the process that makes more of the same kind of organism.

Question 5

What is growth?

Answer 5

Growth is a permanent increase in size an dry mass.

Question 6

What is sensitivity?

Answer 6

Sensitivity is the ability to detect and respond to changes in the internal or external environment.

Question 7

What is excretion?

Answer 7

Excretion is the removal of waste products of metabolism and substances over requirements.

Question 8

Explain how living organisms are classified.

Answer 8

Living organisms are mainly classified into eukaryotes and prokaryotes, which are also classified. Eukaryotes are classified into the protist kingdom, fungi kingdom, plant kingdom, and animal kingdom. The animal kingdom is further classified into vertebrates and invertebrates Similarly, vertebrates are classified into fish, amphibians, reptiles, birds, and mammals. Additionally, in-vertebrates are classified into annelids, mollusks, arthropods, arachnids, echinoderms, and protozoa. Arthropods are classified into crustaceans, insects, arachnids, and myriapods. The plant kingdom is classified into ferns, and flowering plants. Prokaryotes are further classified into viruses.

Question 9

What are the main characteristics of the protist kingdom? Include examples.

Answer 9

1 Unicellular or multicellular bodies.
2 Cells with or without cell walls and chloroplasts.
3 Some species are autotrophic, rest are heterotrophic.
4 All species have cells with a nucleus.
Eg: Parameciums
Chlamydomonas
Seaweeds

Question 10

What are the main characteristics of the fungi kingdom? Include examples, and explain the structure of a fungus cell.

Answer 10

1 Multicellular bodies (very few are unicellular)
2 Don’t have chloroplasts (non-photosynthetic)
3 Are heterotrophic ( digest food first and then absorb it into their bodies)
4 Feed by parasitic or saprophytic means on organic dead organic matter.
5 Release digestive enzymes to break down organic material or their or their host, Store food as glycogen.
6 Important decomposers & recyclers of nutrients in the environment.
7 Nonmotile, Lacks true roots, stems, and leaves.
8 Cell walls are made of chitin.
9 Grow as microscopic tubes or filaments called hyphae that contain cytoplasm, and nuclei.
10 Hyphal networks are called mycelium.
11 Reproduce by sexual, and asexual spores.
12 Grow best in warm, moist environments preferring shade.
Eg: Edible mushrooms (the most commonly known)
Athlete’s foot
Ringworms
Panama disease
Yeasts
Molds
Mushrooms
Puffballs
Rusts
Smuts
A fungus cell’s outermost layer is the cell wall, while the second outermost layer is the cell membrane. Inside the cell are the cytoplasm, the nucleus, the contractile vacuole, and the food granules.

Question 11

What are the main characteristics of crustaceans? Include examples.

Answer 11

1 More than 4 pairs of jointed legs.
2 Breathe through the gills.
3 Have compound eyes with light-sensitive cells.
4 Antennae are present (sensitive to chemicals and touch).
5 Mostly marine.
Eg: Crabs
Lobsters

Question 12

What are the main characteristics of insects? Include examples.

Answer 12

1 Show a segmented body with 3 pairs of jointed legs, compound eyes, and typically 2 pairs of wings.
2 The segments are grouped into head, thorax, and abdomen.
3 Breathe through the trachea.
4 Antennae present.
5 Mostly terrestrial.
6 The exoskeleton prevents desiccation even in dry and very hot climates.
Eg: Locusts
Moths
House Flies
Grasshoppers

Question 13

What are the main characteristics of arachnids? Include examples.

Answer 13

1 More than 4 pairs of jointed legs.
2 The body is divided into 2 regions- cephalothoraxes and abdomen.
3 They have 4 pairs of wings on the cephalothoraxes, 2 pedipalps, and 2 chelicerae.
4 The pedipalps are used in reproduction; the chelicerae pierce the prey and paralyze it with a poison secreted by a gland at their base.
5 Breathe through gills and book lungs.
6 Mostly terrestrial.
Eg; Spiders
Scorpions

Question 14

What are the main characteristics if myriapods? Include examples.

Answer 14

1 Body consists of many segments.
2 Each segment has jointed legs.
3 Show antennae and simple eyes.
4 They can be both herbivores and carnivores.
5 Terrestrial.
Eg: Millipedes
Centipedes

Question 15

What are the main characteristics of fish? Include examples.

Answer 15

1 Are cold-blooded.
2 Have streamlined bodies, which offer minimal resistance to the water.
3 Have scales on their bodies.
4 May be herbivores or carnivores.
5 Reproduces sexually, but fertilization takes place externally (the female lays eggs in water and the male sheds the sperms on them).
6 Have fins, which play a part in the movement.
7 Breathe through the gills.
8 Show the presence of 2 chambered hearts.
Eg: Mackerels
Pomfrets
Tunas
Salmons

Question 16

What are the main characteristics of amphibians? Include examples.

Answer 16

1 Give birth to offspring by laying eggs.
2 Are cold-blooded.
3 Have 4 limbs and no scales.
3 Terrestrial and aquatic.
4 Have moist skins with a good supply of capillaries that can exchange oxygen and carbon dioxide with the air or water.
5 Breathe through gills when young; when mature, breathe through the lungs but the diaphragm and ribs are present.
5 Reproduces sexually but fertilization takes place externally.
6 Adult often lives on land.
7 Show the presence of 3 chambered heart.
Eg: Frogs
Salamanders
Toads
Newts

Question 17

What are the main characteristics of reptiles? Include examples.

Answer 17

1 The skin of the reptile is dry and forms patterns of scales, and the dry skin resists water loss.
2 Cold-blooded vertebrates with 4 limbs, each have 5 toes.
3 Terrestrial
4 Reproduces sexually and the fertilization takes place internally.
5 Give birth to offspring by laying eggs.
6 Egg shells are rubbery.
7 3 heart chambers
Eg: Crocodiles
Snakes
Lizards
Turtles
Tortoises

Question 18

What are the main characteristics of birds? Include examples.

Answer 18

1 Don’t have teeth, instead have a beak.
2 Have hollow bones.
3 Warm-blooded vertebrates with 4 limbs and are modified to form wings.
4 Egg shells are hard
5 The feet have 4 toes with claws that help the bird perch, scratch for seeds, or capture prey, according to the species.
6 The upper and lower jaw are extended to form the beak used for feeding.
7 Breathe through the lungs.
8 Fertilization is internal the female lays the hard-shelled eggs in a nest where she incubates them.
8 4 heart chambers
Eg: Flamingo
Eagle
Hawk
Sparrow

Question 19

What are the main characteristics of mammals? Include examples.

Answer 19

1 Are warm-blooded
2 Can maintain a constant body temperature
3 Have different types of teeth
4 Have skin covered by hair
5 Give birth to live young offspring ( eggs are fertilized internally and undergo a period of development in the uterus)
6 Females have mammary (milk-secreting) glands that produce milk to feed young ones.
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