4.3.6 variation

Question 1

continuous variation

Answer 1

variation where there’s 2 extremes & full range of values in between eg. line graph

Question 2

discontinuous variation

Answer 2

where there are distinct categories & nothing in between eg. bar chart

Question 3

environmental variation

Answer 3

variation caused by response to environmental factors eg. light intensity

Question 4

genetic variation

Answer 4

variation caused by possessing different combination of alleles

Question 5

interspecific variation

Answer 5

differences between species

Question 6

intraspecific variation

Answer 6

variation between members of the same species

Question 7

variation

Answer 7

presence of variety - differences between individuals

Question 8

the greater the…. the greater the intraspecific variation

Answer 8

genetic diversity of a population

Question 9

where are most values in continuous variation

Answer 9

close to mean value

Question 10

what is continuous variation often regulated by

Answer 10

more than 1 gene & can be influenced by environment in which organism lives

Question 11

examples of continuous variation

Answer 11

• height in humans
• length of leaves on an oak tree
• length of stalk (reproductive hypha) of a toadstool
• number of flagella on bacterium

Question 12

which variation is usually quantifiable

Answer 12

continuous

Question 13

what’s the best type of graph to use for continuous variation

Answer 13

histogram

Question 14

what is discontinuous variation often regulated by

Answer 14

single gene & not influenced by environment in which organism lives

Question 15

examples of discontinuous variation

Answer 15

• gender –> mammals either female or male, plants either female/male/hermaphrodite
• some bacteria have flagella, others don’t
• human blood groups (either A, B, AB, O)

Question 16

what’s the best type of graph to use for discontinuous variation

Answer 16

bar chart

Question 17

2 general causes of variation

Answer 17

• genetic
• environmental

Question 18

describe inherited/genetic variation

Answer 18

• inherit genes from parents which provide info to define our characteristics
• combination of alleles inherited aren’t the same as any other living thing (except if have identical twin)
• we may share alleles with other members of species/other species but never complete match

Question 19

describe environmental variation

Answer 19

• characteristics impacted by environment
  eg. skin will tan/get darker with exposure to sunlight

Question 20

examples of characteristics affected by both environmental & genetic variation

Answer 20

• humans have become taller due to better diet however, you’re unlikely to grow very tall if the rest of your family are short as height is limited by genes
• not all genes active at any one time eg. when you reach puberty, changes occur as diff. genes are becoming active
• changes in environment can also directly affect which genes are active