B1.1

Question 1

What is classification?

Answer 1

Organising living organisms into groups

Question 2

What are the 5 kingdoms living things are grouped into?

Answer 2

plants
animals
fungi
protoctista
prokaryote

Question 3

Name some characteristics of plants

Answer 3

contain chlorophyll
autotrophs- make their own food by photosynthesis
rigid cell wall - supports cell
multicellular

Question 4

Name some characteristics of animals

Answer 4

heterotrophs - eat other organisms
multicellular
no cell wall
no chloroplasts

Question 5

Name some characteristics of fungi

Answer 5

Saprophytes - feed off dead organisms and matter
multicellular
cell wall
no chlorophyll

Question 6

Name some characteristics of protoctista

Answer 6

unicellular - single celled
nucleus
e.g algae

Question 7

Name some characteristics of prokaryote

Answer 7

unicellular
no nucleus
e.g bacteria

Question 8

What are the differences between vertebrates and invertebrates?

Answer 8

vertebrates have a backbone and internal skeleton

Invertebrates don’t - some have external skeleton

Question 9

What are the 5 groups vertebrates are divided into?

Answer 9

fish
amphibians
reptiles
birds
mammals

Question 10

How are vertebrates divided into classes?

Answer 10

How they absorb oxygen:
lungs (e.g birds), gills (e.g fish), skin (e.g reptiles)

How they reproduce:
fertilisation occurs internally (e.g mammals) or externally (e.g fish)
oviparous- lay eggs (e.g reptiles), viviparous- give birth to live young and feed them milk (e.g mammals)

How they regulate body temperature:
homeotherms - warm blooded, use homeostasis (e.g mammals) poikilotherms - cold blooded , use environment (e.g reptiles)

Question 11

What is the binomial system?

Answer 11

gives each species 2 part latin name
1st genus, 2nd species
e.g humans are homo sapiens

Question 12

How does the binomial system help scientists?

Answer 12

enables them to:
identify species
study species
conserve species
target conservation efforts

Question 13

What is a ring species?

Answer 13

A group of related populations living in neighbouring areas

Populations next to each other can interbreed and produce fertile offspring, populations further apart can’t

Question 14

What are the 2 types of variation?

Answer 14

continuous and discontinous

Question 15

What are the differences between the two types of variation?

Answer 15

continuous- individuals in a population vary within a range. no distinct categories (e.g human height, number of leaves on a tree)

discontinuous - two or more distinct categories, individuals only fall into one or the other (e.g human blood group, bacteria either antibiotic resistant or not)

Question 16

What causes genetic variation?

Answer 16

characteristics determined by genes inherited from parents
most animals get genes from mother and father

mutations can also cause differences in characteristics of individuals

e.g eye colour, blood group, inherited disorders

Question 17

What causes environmental variation?

Answer 17

environment organisms live and grow in can cause differences between members of same species
covers wide range of differences

e.g diet, exercise, temperature, light level, amount of water

Question 18

What variation is caused by genes and the environment?

Answer 18

most characteristics determined by combination of both
e.g weight, height, skin colour

e.g maximum height a plant can grow determined by genes but environment determines how tall it actually grows

Question 19

What is natural selection?

Answer 19

survival of the fittest

Theory by Charles Darwin to explain evolution

Question 20

What is evolution?

Answer 20

the slow and continuous change of organisms from one generation to the next

Question 21

How does natural selection work?

Answer 21

most organisms produce more young than will survive to adulthood, population don’t dramatically increase as organisms have to compete for limited resources e.g food, water, mates
those with useful characteristics better adapted so more likely to survive and reproduce- useful characteristics passed on
those with less useful characteristics less likely to survive and reproduce, less able to compete
eventually, higher proportion of organisms with useful characteristics for survival compared to poorly adapted
eventually, less useful characteristics may be lost

Question 22

What evidence is there to support evolution?

Answer 22

theory suggests all organisms evolved from shared common ancestors
closely related species evolved into separate species more recently , should have more similar DNA
what scientists discovered with humans and chimps

Warfarin used to kill rats
certain gene gives them resistance to it, able to survive and reproduce- gene passed on
now rat populations that are warfarin-resistant

Question 23

How do organisms adapt to living in the deep sea?

Answer 23

virtually no light- plants can’t photosynehsise so less food

fish can emit light from parts of body (e.g Angler fish. rod-shaped spine in face, gives out light and attracts prey)
often have huge mouths (e.g rat tail moves along seabed scooping up food particles)
huge eyes adapted to dark
long feelers to locate prey

Question 24

How do organisms adapt to polar regions?

Answer 24

Polar Bears- Arctic
compact shape- small surface area, reduce heat loss
thick layer of blubber- insulation, acts as energy source when no food
thick coat- traps layer of air near skin for warmth
greasy fur- sheds water, prevents heat loss through evaporation
large feet- stops them sinking in the snow

Penguins- Antarctic
layer of insulating fat
oily feathers- shed water, reduce heat loss
huddle together - conserve heat
streamlined body - reduce water resistance, swim fast to catch fish

Question 25

How do organisms adapt to volcanic vents?

Answer 25

bacteria producers
bacteria use chemicals to make food through chemosynthesis
other organisms feed off bacteria

Question 26

What is speciation?

Answer 26

populations of the same species become so different they can’t interbreed and produce fertile offspring
they become a whole new species

Question 27

How does speciaton work?

Answer 27

isolation. populations of species separated by barrier (e,g floods)
conditions either side of barrier slightly different (e.g temperature/ climate). different characteristics become more common either side due to natural selection
eventually individuals from different populations will have changed so much they can’t breed to produce fertile offspring and will become a new species

Question 28

What are genetic diagrams?

Answer 28

diagrams to show possible genes of offspring and the likelihood of a genetic disorder being passed on
letters represent alleles - two the same, homozygous, two different- heterozygous
if heterozygous, only one can determine characteristic present. the allele for the characteristic shown is dominant and the other recessive
to display recessive characteristic, must be homozygous recessive
to display dominant can be homozygous dominant or heterozygous as dominant allele overrules

Question 29

What is cystic fibrosis?

Answer 29

genetic disorder of cell membranes caused by two recessive alleles
body produces lots of thick sticky mucus in the air passages, gut and pancreas
symptoms include: breathing difficulties, lung infections, malnutrition and fertility problems

Question 30

What is sickle cell anaemia?

Answer 30

genetic disorder characterised by funny shaped red blood cells
caused by inheriting two recessive alleles
red blood cells can get stuck in capillaries and deprive the body cells of oxygen
symptoms include: tiredness, painful joints and muscles, fever and anaemia