5.2, 5.3 and 5.4 Definitions

Question 1

Distribution

Answer 1

The area inhabited by a plant or animal species.

Question 2

Density

Answer 2

The number of a species living within an area.

Question 3

Ecosystem

Answer 3

Communities of organisms that interact with each other and their environment.

Question 4

Biotic factors

Answer 4

The living things (organisms) in an ecosystem.

Question 5

Abiotic factors

Answer 5

The non-living features in an ecosystem.

Question 6

Tolerance range

Answer 6

Range of an abiotic factor in the environment in which an organism can survive.

Question 7

Optimum range

Answer 7

The range, within a tolerance range for a particular abiotic factor, in which an organism functions best.

Question 8

Biodiversity

Answer 8

The variety of species of biological organisms, often in relation to a particular area.

Question 9

Sampling methods

Answer 9

Techniques used to determine the density and distribution of various populations and communities within an ecosystem.

Question 10

Transects

Answer 10

A sampling area along a straight line in which the number of organisms in that area is counted and recorded.

Question 11

Quadrats

Answer 11

A sampling area, often one square metre, in which the number of organisms in that area is counted and recorded.

Question 12

mark, release and recapture

Answer 12

A sampling method used to determine the abundance of mobile species.

Question 13

Root hairs

Answer 13

Tube-like outgrowths of cells on the surface of roots. They have thin walls, which allow water and dissolved substances to move into the root.

Question 14

Phloem

Answer 14

Long, narrow, living cells that are joined together to form long tubes in a plant. The tubes move the food made in the leaves to other parts of the plant, such as the roots and storage areas.

Question 15

Xylem vessels

Answer 15

Long narrow cells that are joined together to form long tubes in a plant. The tubes, made from xylem cells, move water and dissolved minerals up from the roots to the stem and leaves. The wood in a tree trunk consists mostly of dead xylem cells.

Question 16

Vascular bundles

Answer 16

Group of xylem and phloem vessels within a plant stem.

Question 17

Translocation

Answer 17

Transport of materials, such as water and glucose, in plants.

Question 18

Transpiration stream

Answer 18

Movement of water through a plant as a result of loss of water from the leaves.

Question 19

Transpiration

Answer 19

Loss of water from plant leaves through their stomata.

Question 20

Organelles

Answer 20

Small structure in a cell with a special function.

Question 21

Chloroplasts

Answer 21

Oval-shaped organelle found only in plant cells. Chloroplasts contain the pigment chlorophyll. They are the ‘factories’ in which carbon dioxide and water are changed by sunlight and water into food by the process of photosynthesis.

Question 22

Chlorophyll

Answer 22

The green-coloured chemical in plants that absorbs the light energy used in photosynthesis, which makes food from carbon dioxide and water.

Question 23

Light energy

Answer 23

Energy from the light of the sun, absorbed by plants and used in photosynthesis.

Question 24

Glucose

Answer 24

A simple carbohydrate and the simplest form of sugar.

Question 25

Flaccid

Answer 25

Limp, not firm.

Question 26

Turgid

Answer 26

Firm, distended.

Question 27

Stomata

Answer 27

Pores that exchange gases found on the surface of leaves. They are bordered by guard cells that change the size of the opening of the stomata.

Question 28

Guard cells

Answer 28

Cells surrounding each stoma in a leaf enabling it to open or close depending on the availability of water.

Question 29

Stoma

Answer 29

Small openings through which water transfer occurs, located mainly on the lower surface of leaves. These pores are opened and closed by guard cells. Plural = stomata

Question 30

Flowers

Answer 30

The sexually reproductive structure of some plants.

Question 31

Gametes

Answer 31

Sex cells.

Question 32

Anthers

Answer 32

The part of a flower that produces pollen (the male gametes).

Question 33

Pollen grains

Answer 33

The male gametes of a flower.

Question 34

Ova

Answer 34

Female gametes (eggs) or sex cells.

Question 35

Ovary

Answer 35

In plants, the hollow, lower end of the carpel containing the ovules (the female egg cells); in animals, the female organ that produces ova and reproductive hormones.

Question 36

Fertilisation

Answer 36

Penetration of the ovum by a sperm.

Question 37

Pollination

Answer 37

Transfer of pollen from the stamen (the male part) of a flower to the stigma (the female part) of a flower.

Question 38

Stigma

Answer 38

The female part of a flower, at the top of the carpel, that catches the pollen during pollination.

Question 39

Self-pollination

Answer 39

Transfer of pollen from the flower’s own stamen to its stigma.

Question 40

Cross-pollination

Answer 40

Transfer of pollen from stamens of one flower to the stigma of a flower of another plant of the same type.

Question 41

Wind pollination

Answer 41

Transfer of pollen from one flower to another by the wind.

Question 42

Insect pollination

Answer 42

Transfer of pollen from one flower to another by insects.

Question 43

Vectors

Answer 43

An organism that carries a pathogen between other organisms without being affected by the disease the pathogen causes; an organism that carries and disperses reproductive structures (e.g. pollen) of a different species.

Question 44

Pollinators

Answer 44

Something that transfers pollen from one flower to another.

Question 45

Autotrophs

Answer 45

See producer.

Question 46

Producer

Answer 46

Organism at the base of the food chain that does not need to feed on other organisms; also known as an autotroph.

Question 47

Photosynthesis

Answer 47

The food-making process in plants that takes place in chloroplasts within cells. The process uses carbon dioxide, water and energy from the sun.