Ecology

Question 1

Camouflage

Answer 1

some organisms resemble others so they are concealed, e.g. stick insects resemblewoody stems.

Question 2

Pollination

Answer 2

the transfer of pollen grains from the anthers to the stigmas of flowers

Question 3

Support

Answer 3

some organisms use others for support, e.g. birds build nests in tree

Question 4

Protection

Answer 4

some organisms use others for protection, e.g. grasshoppers live in long grass.

Question 5

Competition

Answer 5

members of the same species and of different species may compete with each other. Animals compete for food, space, a mate and shelter. Plants compete for light, water and minerals.

Question 6

State the ultimate source of energy in a food chain or web.

Answer 6

Sunlight energy
During photosynthesis, primary producers absorb sunlight energy and convert it into chemical energy, which is stored in organic food molecules. Some of this energy is then released during respiration and some is passed on through the organic molecules.

Question 7

Why only 10% of energy is passed down. Limited number of trophic levels

Answer 7

Because there is less energy and biomass at each trophic level in a food chain, fewer organisms can be supported at each level.
Due to the loss of energy and biomass at each level, food chains rarely exceed four or five trophic levels.

Question 8

How energy is lost from one trophic level to another.

Answer 8

At each trophic level in a food chain, energy and biomass (amount of biological matter) are lost. Some organic matter containing energy is lost in FAECES and some is lost in organic EXCRETORY PRODUCTS, e.g. urea. Some is used in RESPIRATION during which the stored energy is RELEASED AND USED, or LOST AS HEAT. The remaining energy containing organic matter is used in GROWTH AND REPAIR, and is then passed on to the next trophic level when organisms are consumed. Organisms not consumed eventually die

Question 9

How energy is gained from one trophic level to another

Answer 9

The organic matter in faeces, excretory products and dead organisms is decomposed by decomposers and they release the energy during respiration. Energy, therefore, flows from producers to consumers to decomposers in one direction through ecosystems, and is not recycled. In general, only 10% of the energy from one level is transferred to the next level.

Question 10

GRIMNER

Answer 10

the seven life processes;
growth,
reproduction,
irritability,
movement,
nutrition,
excretion,
reproduction.

Question 11

Nutrition (feeding):

Answer 11

the process by which living organisms obtain or make food.

Animals take in ready-made food and are called heterotrophs. Plants make their own food and are called autotrophs.

Question 12

Respiration:

Answer 12

the process by which energy is released from food by all living cells.

Aerobic respiration requires oxygen and takes place in most cells. Anaerobic respiration takes place without oxygen in certain cells.

Question 13

Excretion:

Answer 13

the process by which waste and harmful substances, produced by chemical reactions occuring inside body cells
i.e the body’s metabolism, are removed from the body

Question 14

Movement

Answer 14

is a change in the position of a whole organism or of parts of an organism.

Most animals can move their whole bodies from place to place. Plants and some animals can only move parts of their bodies

Question 15

Irritability (sensitivity):

Answer 15

the ability of organisms to detect and respond to changes in their environment or within themselves.

Question 16

Growth

Answer 16

Growth: a permanent increase in the size and complexity of an organism

Question 17

Reproduction:

Answer 17

the process by which living organisms generate new individuals of the same kind as themselves.

Asexual reproduction requires only one parent. Sexual reproduction requires two parents.

Question 18

Types of methods to classify organisms- via DNA

Answer 18

useing the molecular structure of deoxyribonucleic caid (DNA) to assist in grouping organisms

The greater similarity in their DNA structure, the more closely related are the organisms.

Question 19

Another type of methods to classify living organisms

Answer 19

by analyzing visual characteristics i.e number of legs, number of body parts, shape, arrangement of veins in a leaf or an insect wing’s.

Question 20

Another type of methods to classify living organisms-

Species

Answer 20

The basic category of classification is the species. A species is a group of organisms of common ancestry that closely resemble each other and are normally capable of interbreeding to produce fertile offspring.

Question 21

Grouping of organisms

Answer 21

species —-> genera —–> families —–> orders —–> classes —–> phyla —-> kingdoms

Question 22

Ecology

Answer 22

the study of the interrelationships of living organisms with each other and with their environment

Question 23

Environment

Answer 23

the combination of factors that surround and act upon an organism.

Question 24

Biotic factors

Answer 24

all the other living organisms that are present such as predators, prey, competitors, parasites and pathogens

Question 25

Abiotic factors:

Answer 25

all the non-living chemical and physical factors

Question 26

Habitat

Answer 26

the place where a particular organism lives.

For example, the habitat of an earthworm is the upper layers of the soil

Question 27

Population

Answer 27

all the members of a particular species living together in a particular habitat.

For example, all the sea urchins living in a sea grass bed form a population.

Question 28

Community:

Answer 28

all the populations of different species living together in a particular habitat.

For example, a woodland community consists of all the plants, animals and decomposers that inhabit the wood.

Question 28

Ecosystem:

Answer 28

a community of living organisms interacting with each other and with their abiotic environment

Examples of ecosystems include a pond, a coral reef, a mangrove swamp, a grassland and a forest.

Question 29

Niche

Answer 29

the position or role of an organism within an ecosystem.

For example, an earthworm’s niche is to burrow through the soil, improving its aeration, drainage and fertility.

Question 30

The aim of studying an ecosystem

Answer 30

The aim of studying any ecosystem is to identify the different species of plants and animals present, to find out where they live, determine their numbers, and find out about the relationships they have with each other and with the abiotic factors.

Question 31

Herbivores

Answer 31

consume plants, e.g. cows, grasshoppers, snails, slugs, parrotfish, sea urchin

Question 32

Carnivores

Answer 32

consume animals, e.g. lizards, toads, spiders, centipedes, eagles, octopuses, sharks.

Question 33

Omnivores

Answer 33

consume both plants and animals, e.g. hummingbirds, crickets, humans, crayfish.