Topic 6 p2

Question 1

What is the allele that causes cystic fibrosis

Answer 1

Recessive allele f

Question 2

Because it is recessive people with only 1 copy of the allele won’t have the disorder. What r they known as

Answer 2

Carriers

Question 3

What must the parents have for their child to get cystic fibrosis

Answer 3

They must be either carriers Or have the disorder themselves

Question 4

What is polydactyly

Answer 4

It is a genetic disorder where a baby is born with extra fingers or toes and it isn’t life-threatening

Question 5

What is polydactyly caused by

Answer 5

A dominant Allele D so you can be inherited if just one parent carries the defective allele. The parent who has the defective allele will also have the condition because the allele is dominant

Question 6

What can embryos be screened for

Answer 6

To find any genetic disorders

Question 7

Why did people not understand Mendels work until after his death

Answer 7

His workers need to scientists and they had no idea about genes DNA and chromosomes

Question 8

What is the theory of evolution

Answer 8

All of today’s species have evolved from simple life forms first started developing over 3 billion years ago

Question 9

What was Charles Darwin’s theory of evolution

Answer 9

The successful organisms that survive are more likely to reproduce and pass on their genes. Overtime beneficial characteristics become more common in the population and the species changes (it evolves)

Question 10

Why do new phenotypic variations arise

Answer 10

Because genetic variants produced by mutations

Question 11

What is specification

Answer 11

Development of a new species

Question 12

How does specification happen

Answer 12

When populations of the same species change enough to become reproductively isolated, this means that they can’t interbreed to produce fertile offspring

Question 13

What is extinction

Answer 13

When no individuals of a species remain

Question 14

How do species become extinct

Answer 14

Environmental changes, a new predator kills them all, a new disease kills them all, they can’t compete with another species for food, a catastrophic event happens that kills them all like a volcano

Question 15

Why didn’t everyone agree with Darwin’s theory

Answer 15

It went against religious beliefs Darwin couldn’t explain why these new useful characteristics appeared or how they were passed on and he didn’t know anything about genes or mutations there wasn’t enough evidence to convince scientists

Question 16

What scientist had a different idea to Darwin

Answer 16

Lamarck and he argued that changes that an organism acquires during its lifetime will be passed on to its offspring

Question 17

Why was Lamarck’s hypotheses rejected

Answer 17

Because experiments didn’t support his hypotheses

Question 18

Why was Darwin’s theory accepted

Answer 18

The discovery of genetics supported his idea because it provided an explanation of how organisms born with beneficial characteristics can pass them on

Question 19

What is the main drawback to selective breeding

Answer 19

It’s reduces the gene pool

Question 20

What is a gene pool

Answer 20

The number of different alleles in a population

Question 21

What is inbreeding

Answer 21

When a farmer keeps breeding from the best animals or plants which are closely related

Question 22

What can inbreeding cause

Answer 22

Health problems because there’s more chance of the organisms inheriting harmful genetic defects when the gene pool is limited. There can also be serious problems if a new disease appears because there’s not much variation in the population so if one is killed by a new disease the others are also likely to die

Question 23

What is selective breeding

Answer 23

When humans artificially select plants or animals that are going to breed so that the genes for particular characteristics remain in the population

Question 24

What can selective breeding be used for in agriculture

Answer 24

To improve yields for example to improve meat yields a farmer could bring together cows and bulls with the best characteristics for producing meat and after doing this for several generations the farmer would get cows with a very high meat yield

Question 25

He was Alfred Russell Wallace

Answer 25

He proposed the theory of evolution by natural selection and had joint writings with Darwin he was best known for his work on warning colouration in animals and his theory of speciation. Overtime more evidence lead to understanding his theory

Question 26

When did Wallace and Darwin publish their work on natural section

Answer 26

1858 this then promoted Darwin to publish on the origin of species in 1859