Topic 1- Classification, Variation and Inheritance

Question 0

Allele

Answer 0

Different versions of the same gene, e.g. Allele for Blue eyes or Green eyes.

Question 1

Adaptation

Answer 1

Organisms have certain characteristics that allow them to survive in particular places. These characteristics are called adaptations.

Question 2

Autotrophic

Answer 2

Can make food from small molecules e.g. photosynthesis.

Question 3

Bacteria

Answer 3

Single-celled organism that does not have a nucleus (Prokaryote kingdom).

Question 4

Amphibians

Answer 4

One of the five kingdoms- moist permeable skin, lay eggs (oviparous) and is a poikilotherm.

Question 5

Binomial system (Higher)

Answer 5

System of naming organisms using two Latin words- from Genus and Species names.

Question 6

Species

Answer 6

Groups of organisms that have many features in common. Can interbreed to produce fertile offspring.

Question 7

Genus

Answer 7

Contains several species with similar characteristics.

Question 8

Family

Answer 8

Comprising of several genera.

Question 9

Order

Answer 9

Comprising of several families.

Question 10

Class

Answer 10

Comprising of several orders, e.g. Mammals, Reptiles…

Question 11

Phylum

Answer 11

Comprising of several classes, e.g. Chordata.

Question 12

Kingdom

Answer 12

Top five groups of the classification system.

Question 13

Animalia

Answer 13

Animals are multicellular, do not have cell walls, do not have chlorophyll, feed heterotrophically (heterotrophs can’t make their own food).

Question 14

Plantae

Answer 14

Are multicellular, have cell walls, have chlorophyll, feed autotroprically (autotrophs can make their own food).

Question 15

Fungi

Answer 15

Multicellular, have cell walls, do not have chlorophyll, feed saprophytically (saprophytes feed off dead organisms and decaying material).

Question 16

Protoctista

Answer 16

Unicellular (single celled), have a nucleus, protoctista include algae.

Question 17

Prokaryotes

Answer 17

Unicellular (single celled), have no nucleus e.g. bacteria.

Question 18

Viruses

Answer 18

Smaller than bacteria, cannot reproduce themselves, have protein coat containing a few genes, they invade cells and make them reproduce the invading virus.

Question 19

Chordata

Answer 19

Animals with a supporting rod running the length of the body, an example of this being the backbone in vertebrates.

Question 20

Vertebrates

Answer 20

Vertebrates are divided into five classes, groups of amphibians, birds, fish, mammals and reptiles.

Question 21

Internal fertilisation

Answer 21

Fertilisation inside the body.

Question 22

External fertilisation

Answer 22

Fertilisation outside the body.

Question 23

Oviparous

Answer 23

Lays eggs.

Question 24

Viviparous

Answer 24

Gives birth to live young.

Question 25

Homeotherms

Answer 25

Warm blooded- can control their own body temperature.

Question 26

Poikilotherms

Answer 26

Cold blooded- body temperature is affected by surroundings.

Question 27

Hybrid (Higher)

Answer 27

An organism produced as a result of two different species interbreeding. Will have characteristics of both.

Question 28

Extremophiles

Answer 28

May be tolerant to high levels of salt, high temperatures or high pressures.

Question 29

Ring species (Higher)

Answer 29

A group of related populations that live near each other, neighboring populations may interbreed but those well separated geographically may not. Sorting out which are genuinely different species is not easy.

Question 30

Variation

Answer 30

Most populations of organisms contain individuals which vary slightly from one to another, those with superior characteristics are more likely to survive.

Question 31

Over-production

Answer 31

Most organisms produce more young than will survive to adulthood ensuring some will survive.

Question 32

Struggle for existence

Answer 32

Populations do not generally increase rapidly in size there must therefore be considerable competition for survival between the organisms.

Question 33

Survival

Answer 33

Those with advantageous characteristics are more likely to survive.

Question 34

Advantageous characteristics

Answer 34

Better adapted organisms are more likely to reproduce successfully passing on the advantageous characteristics to their offspring.

Question 35

Gradual change

Answer 35

Over a period of time the proportion of individuals with the advantageous characteristics in the population will increase compared with the proportion of individuals with poorly adapted characteristics, and the poorly adapted characteristics may eventually be lost.

Question 36

Genetic variation

Answer 36

Variation caused by inherited genes.

Question 37

Environmental variation

Answer 37

Variation caused by the environment.

Question 38

Continuous variation

Answer 38

When a particular characteristic of an individual lies within a range with no distinct category.

Question 39

Discontinuous variation

Answer 39

When a particular characteristic of the species fits into a few particular and specific categories with no range of variation.

Question 40

Mutation

Answer 40

Mutations that are inherited may change the characteristics of the species (genetic variation).

Question 41

Reproduction

Answer 41

The 'controlled randomness' of the possible gene combinations of the offspring inherited from their parents ensures that no offspring can be identical to either parent (genetic variation).

Question 42

Speciation (Higher)

Answer 42

The development of a new species and can happen when populations of the same original species becomes so different (genetically) that they can no longer interbreed to give fertile offspring.

Question 43

Geographic isolation (Higher)

Answer 43

Two populations of a species become separated, e.g. geographically.

Question 44

Charles Darwin

Answer 44

Invented the theory of evolution by natural selection.

Question 45

Natural selection

Answer 45

The driving force for evolution- the best adapted to survive are able to pass on their advantageous characteristics.

Question 46

Scientific journals

Answer 46

enable new findings to be communicated to other scientists working in the same areas of science, so ideas and knowledge are widely spread AND other scientists can check whether the research is valid.

Question 47

Peer review process

Answer 47

a sort of refereeing system, research papers are read and checked by people competent to understand the contents of research papers (their peers) - this ensures standards are high in terms of 'good scientific practice'.

Question 48

Scientific conferences

Answer 48

Enable scientists to meet and present and discuss their findings, compare their work, listen to new ideas, get ideas to take back to their own research project. Its also a forum for other scientists to hear about research which isn't necessarily exactly their own specialist field, but broadens their own knowledge of related fields of science.

Question 49

Nucleus

Answer 49

The control centre of the cell, containing 23 pairs of chromosomes, on which genes are located.

Question 50

Chromosomes

Answer 50

Carry the genes which control the development and subsequent characteristics of an organism.

Question 51

Gene

Answer 51

A gene is a shorter section of the huge DNA coiled up molecules that make up chromosomes- one gene codes for one characteristic.

Question 52

Genotype

Answer 52

A 'bit of genetic code' pairs of or individual alleles e.g. XX, XY, X, Y.

Question 53

Phenotype

Answer 53

The result of 'gene expression' - the nature of the characteristic you see e.g. tall, blue eyes, male etc.

Question 54

Dominant

Answer 54

If two alleles for a characteristic are different (heterozygous) then only one of the alleles can determine the nature of the characteristic - know as the dominant allele (usually shown as a capital/upper case letter) eg a gene for height might be H, so HH or Hh genotypes will give a tall organism. A dominant allele will override a recessive allele.

Question 55

Recessive

Answer 55

If an allele is not dominant, it is described as recessive (small/lower case letter), and, in order for the recessive allele to be expressed in the phenotype observed, you must have a double recessive allele eg homozygous genotype hh will give rise to phenotype short.

Question 56

Homozygous

Answer 56

If a pair alleles for a characteristic are the same on a gene eg genotype XX (phenotype female).

Question 57

Heterozygous

Answer 57

If a pair of alleles for a characteristic are different on a gene eg genotype XY (phenotype female).

Question 58

Sickle cell disease

Answer 58

Sickle cell anaemia is a genetic (inherited) blood disorder in which red blood cells (the carriers of oxygen around the body), develop abnormally. Instead of being round and flexible, the sickle red blood cells become shaped like a crescent (hence the name 'sickle'). These abnormal red blood cells can then clog sections of blood vessels (especially the narrow capillaries) leading to pain. These painful effects can last from a few minutes to several months. The abnormal blood cells have a shorter life-span and are not replaced as quickly as normal healthy red blood cells leading to a shortage of red blood cells, called anaemia. Symptoms of sickle cell anaemia include tiredness, painful joints and muscles and breathlessness, especially after exercise i.e. any extra physical exertion.

Question 59

Cystic fibrosis

Answer 59

Cystic fibrosis is a genetic disorder disease passed down through families. Cystic fibrosis causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body and is one of the most common chronic lung diseases in children and young adults. Sadly, it is a life-threatening disorder caused by a defective gene which causes the body to produce abnormally thick and sticky fluid, called mucus. The thick mucus builds up in the breathing passages of the lungs (causing lung infections) and in the pancreas, the organ that helps to break down and absorb food (causing digestion problems).