6 Inheritance variation and evolution - Seperate Science

Question 1

Describe how malarial parasites use both forms of reproduction.

Answer 1

Reproduce asexually in the human host, but sexually in the mosquito.

Question 2

Describe how fungi use both forms of reproduction.

Answer 2

Reproduce asexually by spores but also reproduce sexually to give variation.

Question 3

Describe how plants use both forms of reproduction.

Answer 3

Runners such as strawberry plants, or bulb division such as daffodils.

Question 4

Name the three parts of a DNA molecule.

Answer 4

A phosphate group, a sugar molecule and a nucleotide base

Question 5

Name the four nucleotides found in DNA.

Answer 5

Adenine, thymine, guanine and cytosine

Question 6

How many bases code for a particular amino acid?

Answer 6

3

Question 7

What is a set of three nucleotide bases called?

Answer 7

A codon

Question 8

Which cell organelle synthesises proteins?

Answer 8

Ribosomes.

Question 9

How is the protein sequence correctly assembled?

Answer 9

Using a template molecule from the DNA.

Question 10

What brings specific amino acids to the ribosomes?

Answer 10

Carrier molecules.

Question 11

When the protein chain is complete, what process aids it to form its unique shape?

Answer 11

Folding.

Question 12

Name three uses of proteins in the body.

Answer 12

1. Enzymes
2. Hormones
3. Structural proteins e.g. collagen

Question 13

What is a change in the DNA sequence called?

Answer 13

A mutation.

Question 14

Name three potential consequences for a protein of a mutation.

Answer 14

1. No change or a slight change so no effect on the protein
2. Altered protein, so an enzyme may stop working
3. Mutation within a non-coding region nearby to a gene may affect the expression (production) of a protein

Question 15

What is plant tissue culture?

Answer 15

Using small groups of cells from part of a plant to grow identical new plants.

Question 16

What are ?plant cuttings??

Answer 16

An older, but simple, method used by gardeners to produce many identical new plants from a parent plant.

Question 17

Where might plant cloning be useful?

Answer 17

Horticulture and agriculture.

Question 18

Describe the two steps involved in embryo transplanting.

Answer 18

Splitting apart cells from a developing animal embryo before they become specialised transplanting the identical embryos into host mothers.

Question 19

Compare the offspring from embryo transplants with each other and with the parents.

Answer 19

Genetically identical to each other; Different from parents

Question 20

State a disadvantage to cloning plants and animals.

Answer 20

Reduces genetic variation, so makes populations more susceptible to disease.

Question 21

In adult cell cloning, what is removed from the cloning target’s cell, in order to create its clone?

Answer 21

Nucleus

Question 22

What type of cell is taken from the target clone in adult cell cloning?

Answer 22

Any body cell (except gametes)

Question 23

What has to be done to the egg cell in adult cell cloning?

Answer 23

Remove its nucleus

Question 24

What is needed to stimulate the new egg cell to divide in adult cell cloning?

Answer 24

Electric shock

Question 25

Compare the offspring in adult cell cloning to both its parents.

Answer 25

Genetically identical to nucleus donor; different from the egg cell donor

Question 26

Name the person who first discovered inherited characteristics are determined by ‘units’ passed on unchanged.

Answer 26

Gregor Mendel

Question 27

Why were Mendel’s ideas of inheritance not accepted during his time?

Answer 27

As chromosomes were not discovered/seen yet

Question 28

Who published the double helix structure of DNA?

Answer 28

Watson and Crick

Question 29

Watson and Crick used whose work to find out the structure of DNA?

Answer 29

Franklin and Wilkins (but without Franklin’s permission)

Question 30

Name the person who proposed the theory of evolution.

Answer 30

Charles Darwin

Question 31

Name the person who suggested changes that occur in an organism during its lifetime can be inherited.

Answer 31

(Jean-Baptiste) Lamarck

Question 32

On what mechanism is Darwin’s theory of evolution based on?

Answer 32

Natural selection

Question 33

What is Darwin’s theory of evolution by natural selection?

Answer 33

All species have evolved from simple life forms

Question 34

State three reasons why Darwin?s ideas were only slowly accepted.

Answer 34

1. Conflict with the wild belief that God made all living things; 2. Insufficient evidence; 3. No mechanism to explain variation and inheritance

Question 35

Who worked with Darwin to develop the theory of evolution?

Answer 35

Alfred Russel Wallace

Question 36

Apart from evolution, what are two other studies Wallace worked on?

Answer 36

Warning colouration in animals + Theory of speciation

Question 37

What is speciation?

Answer 37

The process by which two species evolve from a single original species by natural selection

Question 38

Give the six steps in the process of speciation.

Answer 38

1. Geographical isolation (e.g. a flood divides an island in two)
2. Different selection pressures/conditions in the new environments
3. Genetic variation (due to mutations) within the groups
4. Best adapted individuals to the new conditions survive, reproduce and pass on these favourable alleles
5. No interbreeding over time, groups become more different to each other
6. After a large amount of time, unable to interbreed successfully. They are now separate species.