B6 Inheritance v2

Question 1

what important point did mendal note

Answer 1

that characterstics in plants were passed on from one generation to the next.

Question 2

what was mendels three conclusions

Answer 2

hereditary units detemine charcteristics in plants. on unit is passed on from each parent. hereditary units can be dominant or recessive

Question 3

what is the specific name for differences within a species

Answer 3

variation

Question 4

why was mendel’s work not used straight away

Answer 4

scientists had not yet discovered genes and chromosomes

Question 5

what are the two types of variation

Answer 5

genetic and environmental

Question 6

what causes genetic variation and how?

Answer 6

different genes, mixed up during sexual reproduction between two parents

Question 7

explain what is meant by environmental variation

Answer 7

the envrionment causing differences between memebers of the same species, such as a plant that does and doesn’t get much sunlight

Question 8

what was Darwin’s main conclusions

Answer 8

“that only organisms with the most suitable characteristics to the environment would survive, known as ‘survival of the fittest’. the
organisms that survive would then pass on these survival characteristics to their offspring. overtime this causes evolution”

Question 9

what is it called when a new species is formed and why is this?

Answer 9

speciation. Because a species has evolved so much because of natural selection and ‘survival of the fittest’

Question 10

give three reasons a species may become extinct.

Answer 10

1- A new disease kills them all. 2- new preadator kills them all. 3- A sharp environmenal change

Question 11

two reasons why Darwin’s discoveries were considered controversial

Answer 11

1- Contrasted to religious beliefs. 2- was the fist theory that didn’t suggest a ‘creator’. 3- lack of evidence to assist his conclusions

Question 12

what did lamarck suggest

Answer 12

That the best survival charcterisitcs would not just be passed on, but improved.

Question 13

what is selective breeding?

Answer 13

when humans artificially select plants or animals to breed so a population contains ertain characteristics

Question 14

what is the main disadvantage of selective breeding?

Answer 14

it reduces the gene pool. meaning most offspring have similrt charcteristics which can lead to interbreeding

Question 15

what two potential complecations can arrive from interbreeding

Answer 15

disease and health problems

Question 16

what is the basic concept of genetic engineering?

Answer 16

to transfer a gene which contains a desirable charcteristic to another organism so it also contains that trait.

Question 17

describe the process of genetic engineering

Answer 17

“gene is cut using an ennzyme and inserted into a vector (usually a virus). vector is then exposed to target organism which then leads
to the useful gene being inserted into its cells. “

Question 18

2 concerns with GM crops

Answer 18

could reduce farmland diversity and unknown defeccts on human health

Question 19

two benefits of GM crops

Answer 19

increased yield, can be used to provide people in poor contires with a nutritious diet.

Question 20

define cloning plants with tissue culture

Answer 20

plants are put nto a growth medium with hormones and grow into new ones

Question 21

describe cloning plants with cuttings

Answer 21

cuttings taken from desired parent plant. this is then planted

Question 22

describe how you can make animal clones

Answer 22

using an embryo transplant. sperm fertilizes egg, embryo then develops and splits. these embryos are then planted into mother cows

Question 23

describe adult cell cloning

Answer 23

“nucleas taken from an unfertilized egg cell and and a basic body cell, these both go into an empty egg cell which is then stimulated by
electric shock. As a result it then divides and is then impanted into the womb of an adult female. “

Question 24

2 concerns with cloning

Answer 24

could cause health problems, religious objections

Question 25

what are fossils

Answer 25

the remains of ancient organisms found in rocks

Question 26

list three processes of fossilisation

Answer 26

gradual replacement by minerals, casts and impressions, preservations

Question 27

what is speciation

Answer 27

the development of a new species

Question 28

how does speciation occur

Answer 28

when populations of the same species have become so different they can no longer interbreed to produce fertile offspring

Question 29

two specific ways speciation occurs

Answer 29

isolation and natural selection

Question 30

what is a defect of interbreeding

Answer 30

more suseptible to diseases

Question 31

describe how a fossil is formed

Answer 31

minerals gradually replace the organism over a long period of time.