Evolution

Question 1

Define evolution

Answer 1

The change in characteristics of a population over several generations

Question 2

Define variation

Answer 2

The differences within a population of organisms

Question 3

Define independent assortment

Answer 3

The process by which chromosomes are randomly separated before the cell splits in meiotic division

Question 4

Define recombination

Answer 4

An event in which two homologous chromosomes ‘swap’ sections with one another in meiosis

Question 5

Define selection pressure

Answer 5

A factor that will impact an organisms ability to survive or reproduce

Question 6

Define abiotic

Answer 6

Non-living

Question 7

Define biotic

Answer 7

Living

Question 8

Define natural selection

Answer 8

Survival of the fittest or the process in which organisms with favorable characteristics have better chance of surviving in a particular environment than others

Question 9

Define fitness

Answer 9

How well suited an organism is to survive and reproduce in its environment or an organisms ability go survive

Question 10

Define artificial selection

Answer 10

The process in which organisms with desirable characteristics are selectively bred

Question 11

Define adaptation

Answer 11

A characteristic or trait that helps an organism survive

Question 12

Define progeny/or offspring

Answer 12

Descendants or children

Question 13

Define mutation

Answer 13

A change in the sequence or type of DNA bases in a gene

Question 14

Define phenotype

Answer 14

The physical appearance of an organism or a characteristic that is expressed

Question 15

Define genotype

Answer 15

The pair of alleles an organism has, for example Gg or gg

Question 16

Define speciation

Answer 16

The evolutionary process by which populations evolve into a distinct species

Question 17

Define organism

Answer 17

A living thing

Question 18

Define gene pool

Answer 18

All of the genes in a population of organisms

Question 19

Define population

Answer 19

All of the organisms of a particular species living in the same place

Question 20

Define competition

Answer 20

Organisms fighting over a resource eg food/place / water or a mate

Question 21

Define meiosis

Answer 21

Cell division of gametes (sperm and ova) that produces 4 genetically different haploid cells

Question 22

Natural selection can only occur if:

Answer 22

1. Variability
2. Trait of interest must be inheritable (heritable)
3. Trait convers advantage (adaptive)

Question 23

There has to be —- for evolution to occur

Answer 23

Variation

Question 24

3 things that lead to variation

Answer 24

1. Independent assortment - random chromosome assortment in cell during meiosis
2. Genetic recombination - an event in which 2 homologous chromosomes ‘ swap’ sections with one another during meiosis
3. Mutations - A change in the sequence or type of DNA bases in a gene which leads to different proteins
   All of which leads to genetic diversity

Question 25

What causes mutations?

Answer 25

Errors in DNA replication or from the damaging effects of mutagens, such as radiation and carcinogens and gene editing

Question 26

Describe the process in which identical twins are formed

Answer 26

One fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information

Question 27

Define epigenetics and how they can make identical twins different

Answer 27

When environment plays a role in expression of DNA. May trigger different genes. E.g cold or hot environment. For example, if a twin were to grow up in a cold environment they may look different from their twin who grew up in a hot environment.

Question 28

Draw a diagram on how identical twins are formed during meiosis

Answer 28

Check book for diagram

Question 29

Define homologous structures

Answer 29

Related species with the same basic structure and genetics Through a shared ancestor For example, cats and lions both have similar paw structures and they share an ancestor

Question 30

Define analogous structures

Answer 30

Not similar genetically but similar structures due to similar environment E.g dolphins and sharks

Question 31

Methods of artificial selection

Answer 31

Cross breeding desirable traits Interbreeding

Question 32

Examples of selective pressures

Answer 32

Predators Environmental conditions Availability of food Diseases

Question 33

Process of speciation in 3 words

Answer 33

1. Variation 2. Isolation 3. Selection

Question 34

Explain how mutations can be advantageous

Answer 34

Mutations can alter genes which can result in advantageous traits to be produced For example, white fur for bears was a result of a mutation which advantageous helping polar bears blend into the snow

Question 35

Explain the difference between natural selection and evolution

Answer 35

Natural selection is when individual species have a higher level of fitness, bettering the chances of surviving to pass on their genes Evolution is when inherited traits of a population change over many generations

Question 36

2 types of gene selection:

Answer 36

Natural and artificial selection

Question 37

Result of gene selection

Answer 37

Specific DNA sequence becomes more prevalent via gene selection

Question 38

Artificial selection benefits Think about GM foods and things humans have genetically modified

Answer 38

Selection of preferred genes (traits) Can make food more nutritious-- higher levels of vitamins such as vitamin-A Making crops, cotton pest, disease resistant Making foods bigger proportions

Question 39

Artificial selection issues/ concerns

Answer 39

Inbreeding - increases the risk of recessive gene diseases and disorders since closely related organisms are more likely to carry a copy of the same recessive gene.

Question 40

Cloning process via somatic cell nuclear transfer

Answer 40

Donor cells planted into surrogate mother's egg Nucleus from somatic cells transferred to the cytoplasm of an enucleated egg - egg becomes zygote (fertilised)

Question 41

Cloning benefits

Answer 41

Prevents extinction of endangered animals Aids the replacement of organs Increase agricultural production Enables same-gender couples to have offspring Can solve infertility

Question 42

Cloning cons

Answer 42

Reduced genetic diversity If there were genes which coded for diseases it'll be passed onto the offspring Ethical concerns - "playing God " identity fraud

Question 43

Which is better: pure bred or mut

Answer 43

Mut because they are genetically healthier

Question 44

Gm food concerns

Answer 44

Can be cross bred with wild plants for example, a pest resistant crop was cross bred with a wild plant the offspring of the wild plant would be also pest resistant Gene transfer Concerns about potential allergies

Question 45

Define recombining genes

Answer 45

Selected gene from one organism placed into another organism

Question 46

Human gene therapy pros

Answer 46

Modifies genes to treat, cure diseases or issues - modified to carry therapeutic genes Potential to cure or treat genetic issues or diseases

Question 47

Gene therapy issues/ concerns

Answer 47

Unwanted immune system reaction- immune system may see the newly introduced viruses as intruders and attack them Introduction to wrong cell-chance of a tumor formation Potential allergic reaction