Chapter 1 - Characteristics and Classification of Living Organisms

Question 1

what is an organism?

Answer 1

a living thing

Question 2

what are the seven characteristics of living organisms? (MRS GREN)

Answer 2

movement, respiration, sensitivity, growth, reproduction, excretion, nutrition

Question 3

growth

Answer 3

all organisms begin small and get larger by the growth of their cells and by adding adding new cells to their body (permanent increase in size and dry mass)

Question 4

movement

Answer 4

all organisms are able to move to some extent, most animals can move their whole body from place to place and plants can slowly move parts of themselves (change of position or place)

Question 5

sensitivity

Answer 5

all organisms pick up information about changes in their environment and react to these changes (internal or external environment)

Question 6

excretion

Answer 6

the removal of waste products produced by metabolic reactions in excess of requeiments from the body

Question 7

reproduction

Answer 7

organisms are able to make new organisms of the same species as themselves

Question 8

nutrition

Answer 8

organisms take substances from their environment and use them to provide energy or materials to make new cells

Question 9

respiration

Answer 9

all organisms break down glucose and other substances inside their cells to release energy that they can use (chemical reaction that breaks down nutrient molecules and release energy for metabolism)

Question 10

metabolism

Answer 10

the chemical reaction that takes place in living organisms

Question 11

species

Answer 11

a group of organisms that can reproduce to produce fertile offsprings

Question 12

are donkeys and horses able to mate with one another? and if so is the offspring fertile?

Answer 12

even though they belong to two different species, they are able to reproduce with one another as they share the same genus, their offspring will be strong and healthy but infertile

Question 13

binomial naming system

Answer 13

a system of naming species that is internationally agreed in which the scientific name is made up of two parts showing the genus and the species

Question 14

genus

Answer 14

a group of species that are related to one another, share similar features and share a common ancestor

Question 15

how is the binomial name written?

Answer 15

the genus comes first and is always written with a capital letter, the second name is the species it belongs to and is written with a small letter

Question 16

dichotomous key

Answer 16

a way of identifying an organisms by working through pairs of statements (about its features) that lead you to its name

Question 17

what is one piece of evidence that tigers and lions are related?

Answer 17

they share the same genus

Question 18

what are two pieces of evidence that lions and tigers belong to different species?

Answer 18

they have different binomial names: panthera tigris and panthera leo as well as together they produce an infertile offspring

Question 19

kingdom

Answer 19

one of the major groups into which all organisms are classified

Question 20

what are the characteristic features of plants?

Answer 20

*their cells have a nucleus and cell walls made of cellulose and often contain chloroplasts
*they feed by photosynthesis
*they may have roots, stems, and leaves (some don’t have these organs)

Question 21

what are the characteristic features of animals?

Answer 21

*their cells have a nucleus but no cell walls or chloroplasts
*they feed on organic substances made by other living organism
*they are multicellular

Question 22

what are the characteristic features of fungi?

Answer 22

*they are usually multicellular but some such as yeast are unicellular
*they have nuclei and cell walls but the walls are not made of cellulose
*they don’t have chlorophyll
*they feed by digesting waste organic material and absorbing it into their cells
*spread or reproduce by spreading spores
*most have hyphae

Question 23

what are the characteristic features of protoctists?

Answer 23

*they are multicellular or unicellular
*their cells have a nucleus and may or may not have a cell wall and chloroplast
*some feed by photosynthesis and others feed on organic substances made by other organisms

Question 24

what are the main characteristic features of prokaryotes:

Answer 24

*they are usually unicellular
*they have no nucleus or mitochondria
*they have cell walls not made of cellulose
*they have a circular loop of DNA which is free in the cytoplasm
*they often have plasmid

Question 25

what is a vertebrate?

Answer 25

animals that have a backbone

Question 26

what are the characteristic features of fish?

Answer 26

*they have scaly skin *they have gills throughout their life so they can breathe *they have fins *their eggs have no shell and are laid in water

Question 27

what is metamorphosis?

Answer 27

changing from a larva with one body form to an adult with a different body form

Question 28

what are the characteristic features of amphibians?

Answer 28

*smooth, moist skin *their eggs have no shells and are laid in water *the tadpoles live in water whilst adults often live on land *tadpoles have gills for gas exchange and adults have lungs

Question 29

what are the characteristic features of reptiles?

Answer 29

*dry, fixed scales on skin *lay eggs with a soft shells on land

Question 30

what are the characteristic features of birds?

Answer 30

*they have feathers and sometimes a few scales *they have a beak *their front two limbs are wings *lay eggs with hard shells *endothermic

Question 31

what are the characteristic features of mammals?

Answer 31

*they have hair on their skin *their young develop in the uterus attached to the mother by a placenta *females have mammary glands which produce milk to feed their young *different kinds if teeth: incisors, canines, premolars and molars *pinna (ear flap) outside the body *sweat glands in the skin *they have a diaphragm *endothermic

Question 32

what are arthropods?

Answer 32

animals with jointed legs but no backbone (invertebrates)

Question 33

what are the three standard features of arthropods?

Answer 33

*exoskeleton *jointed legs *segmented body

Question 34

what are the characteristic features of insects?

Answer 34

*three pairs of jointed legs *two pairs of wings (one or two may be vestigial) *breathe through tubes called tracheae *their body is divided into a head, thorax and abdomen *one pair of antennae *they are mainly land living

Question 35

what are the characteristic features of crustaceans?

Answer 35

*more than four pairs of jointed legs *two pairs of antennae *chalky exoskeleton formed from calcium *breathe through gills *live in water

Question 36

what are the characteristic features of arachnids?

Answer 36

*they have four pairs of jointed legs *no antennae *body divided into two parts - a cephalothorax (brain connected to thorax) and abdomen

Question 37

what are the characteristic features of myriapods?

Answer 37

*body consists of many similar segments *each of their body segments has jointed legs *one pair of antennae

Question 38

what are the characteristic features of ferns?

Answer 38

*plants with roots, stems and leaves (fronds) *don’t produce flowers *reproduce by spores produced on the underside of their fonds

Question 39

what are the characteristic features of flowering plants?

Answer 39

*plants with roots, stem and leaves *reproduce sexually using flowers and seeds *their seeds are produced inside an ovary in the flower *can be divided into two groups - monocotyledons (monocots) and dicotyledons (dicots)

Question 40

what are the characteristic features of dicots?

Answer 40

*seeds with two cotyledons (seed leaves) *usually have a main root with side roots coming from it *leaves have a network of branching veins *flower parts in multiple of four or five *broad leaves *vascular bundle in the stem arranged in a ring

Question 41

what are the characteristic features of monocots?

Answer 41

*seeds with one cotyledons (seed leaves) *roots grow out directly from the stem *long narrow leads *leaves have parallel veins *flower parts in multiples of three *vascular bundle in the stem arranged randomly

Question 42

why are viruses considered a non-living organism?

Answer 42

as they cannot do anything other than just exist until they get inside a living cell, on their own they don’t display the seven characteristics of living things, they simply take over a host’s metabolic pathway in order to make multiple copies of themselves

Question 43

what are spores?

Answer 43

tiny groups of cells with tough, protective outer covering