B6 Ai Flashcards

1
Q

What is DNA?

A

DNA is the chemical that all of the genetic material in a cell is made up from.

DNA contains all the instructions to put an organism together and make it work.

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2
Q

What structure do DNA molecules form?

A

A DNA molecule forms a double helix, which is a double-stranded spiral.

The double helix structure is made up of two strands of DNA coiled together.

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3
Q

Where is DNA found in cells?

A

DNA is found in the nucleus of animal and plant cells.

It is organized into long structures called chromosomes.

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4
Q

What is a chromosome?

A

A chromosome is a really long structure made of DNA.

Chromosomes contain many genes and are found in the nucleus.

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5
Q

What is a gene?

A

A gene is a small section of DNA found on a chromosome.

Each gene codes for a particular sequence of amino acids.

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6
Q

What do genes code for?

A

Genes code for specific proteins by determining the sequence of amino acids.

These amino acids are joined together to form proteins.

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7
Q

What is an organism’s genome?

A

A genome is the term for all of the genetic material in an organism.

Scientists have worked out the whole human genome.

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8
Q

Why is understanding the human genome important for medicine?

A

Understanding the human genome helps scientists find genes linked to diseases and develop treatments.

It also aids in studying tiny differences in genomes to understand population migration.

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9
Q

What are inherited diseases?

A

Inherited diseases are caused by faulty genes passed from parent to offspring.

These diseases can be studied through the identification of specific genes related to them.

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10
Q

What is sexual reproduction?

A

Sexual reproduction involves two parents contributing gametes to form offspring.

Gametes are specialized cells, such as eggs and sperm.

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11
Q

What is asexual reproduction?

A

Asexual reproduction involves only one parent cell producing offspring.

This process does not require gametes.

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12
Q

Fill in the blank: A DNA molecule is made up of two strands of DNA coiled together, forming a _______.

A

double helix

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13
Q

True or False: Each gene codes for a different type of protein.

A

False

Each gene codes for a specific sequence of amino acids that make up a particular protein.

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14
Q

What type of reproduction produces genetically different offspring?

A

Sexual reproduction

Sexual reproduction involves the combination of genetic material from two parents, resulting in offspring that have a mix of genes.

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15
Q

What are the gametes produced by sexual reproduction?

A

Egg and sperm

Gametes are the reproductive cells that fuse during fertilization.

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16
Q

What process produces gametes in sexual reproduction?

A

Meiosis

Meiosis is a type of cell division that reduces the chromosome number by half, resulting in gametes.

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17
Q

What is the result of fertilization in sexual reproduction?

A

Fertilised egg

The fertilized egg contains a full set of chromosomes, half from each parent.

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18
Q

What is the difference between sexual and asexual reproduction?

A

Sexual reproduction involves mixing genes; asexual reproduction does not

In sexual reproduction, genetic variation occurs, while in asexual reproduction, offspring are clones of the parent.

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19
Q

What type of cell division is involved in asexual reproduction?

A

Mitosis

Mitosis is the process where one parent cell divides to produce two genetically identical daughter cells.

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20
Q

Fill in the blank: Asexual reproduction produces genetically _______ cells.

A

identical

Asexual reproduction results in clones, meaning the new cells have the same genetic material as the parent cell.

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21
Q

What is a clone in the context of asexual reproduction?

A

Genetically identical new cell

A clone is an organism or cell that is genetically identical to its parent.

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22
Q

What is the main characteristic of offspring produced by sexual reproduction?

A

Variety in genes

Offspring inherit a mixture of genes from both parents, leading to genetic variation.

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23
Q

True or False: Asexual reproduction involves the fusion of gametes.

A

False

Asexual reproduction does not involve gamete fusion, resulting in identical offspring.

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24
Q

What happens to the number of chromosomes during fertilization?

A

It is restored to a full set

The fertilized egg has a complete set of chromosomes, combining contributions from both parents.

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25
Q

What process produces gametes?

A

Meiosis

Gametes are produced by meiosis, which halves the number of chromosomes.

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26
Q

How many chromosomes do gametes have compared to normal cells?

A

Half the number

Gametes only have half the number of chromosomes of normal cells.

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27
Q

What is the first step of meiosis?

A

The parent cell has chromosomes in pairs

Each parent contributes half of the chromosomes.

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28
Q

What happens to the DNA in the parent cell before meiosis begins?

A

It is copied

This results in X-shaped chromosomes.

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29
Q

What happens after the cell divides in meiosis?

A

Each new cell gets half of the chromosomes

Each cell divides again to form gametes.

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30
Q

How many daughter cells are produced at the end of meiosis?

A

Four

These daughter cells are the gametes.

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31
Q

What is unique about each gamete?

A

They are genetically different

Each has a different combination of the mother’s and father’s chromosomes.

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32
Q

How many pairs of chromosomes do humans have?

A

23 pairs

This includes 22 matched pairs and one pair that determines sex.

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33
Q

What are the sex chromosomes in humans?

A

XX for females, XY for males

The 23rd pair consists of these chromosomes.

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34
Q

What happens during fertilization?

A

Two gametes fuse together

This forms a new cell with the normal number of chromosomes.

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35
Q

What is the result of the new cell after fertilization?

A

It divides by mitosis

This produces many new cells that form an embryo.

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36
Q

What occurs as the embryo develops?

A

Cells differentiate

They become specialized types of cells that make up a whole organism.

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37
Q

In which organs does meiosis occur in humans?

A

Reproductive organs

Meiosis occurs in reproductive organs for making gametes.

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38
Q

Fill in the blank: An embryo is an _____ at an early stage of growth.

A

unborn baby

An embryo is an unborn baby at an early stage of growth.

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39
Q

True or False: Each sperm cell has either an X or a Y chromosome.

A

True

Sperm cells determine the sex of the offspring.

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40
Q

How many pairs of chromosomes are in every human body cell?

A

23 pairs

This includes 22 matched pairs and one pair that determines sex.

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41
Q

What are the two types of sex chromosomes?

A

X and Y chromosomes

The 23rd pair in humans determines biological sex.

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42
Q

What combination of sex chromosomes do males have?

A

XY

The Y chromosome is responsible for male characteristics.

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43
Q

What combination of sex chromosomes do females have?

A

XX

The XX combination allows female characteristics to develop.

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44
Q

What do all sperm cells carry in terms of sex chromosomes?

A

Either an X or a Y chromosome

Sperm determines the sex of the offspring based on which chromosome fertilizes the egg.

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45
Q

What do all egg cells carry in terms of sex chromosomes?

A

An X chromosome

Egg cells are always X, contributing to the sex of the offspring.

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46
Q

What is the purpose of a Punnett square?

A

To find the probability of getting a boy or a girl

It visually represents gamete combinations.

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47
Q

How are the possible gametes arranged in a Punnett square?

A

Female gametes (eggs) on the side and male gametes (sperm) on the top

The intersection shows possible offspring combinations.

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48
Q

What are the possible outcomes from a Punnett square with one X and one Y chromosome?

A

Two XX results and two XY results

Indicates equal probability of male and female offspring.

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49
Q

What is the probability of having a boy or a girl in terms of percentage?

A

50%

Each pregnancy has an independent chance of resulting in a boy or a girl.

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50
Q

True or False: Genetic diagrams can predict exactly what will happen.

A

False

They only show probabilities, not certainties.

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51
Q

What is the primary characteristic of the Y chromosome?

A

It causes male characteristics

The presence of the Y chromosome leads to male phenotype development.

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52
Q

Fill in the blank: All females have two ______ chromosomes.

A

X

This genetic makeup is crucial for female development.

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53
Q

What do genetic diagrams illustrate regarding sex chromosomes?

A

All possible ways X and Y chromosomes could combine

They depict potential genetic outcomes from parental gametes.

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54
Q

What is the definition of a genotype?

A

The mix of alleles you have

Genotype determines the genetic makeup that influences characteristics.

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55
Q

How many genes control characteristics in living organisms?

A

Different characteristics can be controlled by either a single gene or several genes

For example, mouse fur color is controlled by a single gene, while most characteristics are influenced by multiple genes.

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56
Q

What are alleles?

A

Different versions of a gene

Alleles exist in pairs in an organism’s genotype.

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57
Q

What does it mean to be homozygous for a characteristic?

A

Having two identical alleles for that characteristic

For example, BB or bb represent homozygous genotypes.

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58
Q

What are the phenotypes of the offspring when crossing BB and bb hamsters?

A

All offspring will be normal

Normal phenotype results from the dominant allele.

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59
Q

What is a Punnett square used for?

A

To show the possible genetic combinations of offspring from parent genotypes

It illustrates how alleles combine and predict offspring traits.

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60
Q

What is the expected ratio of normal to superpowered hamsters from a Bb x Bb cross?

A

3 normal : 1 superpowered

This ratio is derived from the genetic combinations shown in the Punnett square.

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61
Q

Fill in the blank: The characteristios you have is called your _______.

A

[phenotype]

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62
Q

True or False: The allele that causes hamsters to have superpowers is dominant.

A

False

The superpower allele is recessive, represented by ‘b’.

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63
Q

What is cystic fibrosis?

A

An inherited disorder caused by a recessive allele

It affects the respiratory and digestive systems.

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64
Q

What does polydactyl mean?

A

Having extra fingers or toes

This trait can be inherited and is often dominant.

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65
Q

What is meant by the term ‘inherited disorders’?

A

Conditions passed down from parents to offspring via genes

Examples include cystic fibrosis and polydactyl.

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66
Q

What is the role of genetic diagrams?

A

To show how characteristics are inherited

They provide a visual representation of allele combinations.

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67
Q

What type of disorder is cystic fibrosis?

A

Inherited disorder of cell membranes

Cystic fibrosis is a genetic condition that affects the function of epithelial cells in various organs.

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68
Q

What type of allele causes cystic fibrosis?

A

Recessive allele (+*)

Individuals with one copy of the allele are known as carriers and do not exhibit symptoms.

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69
Q

What is the phenotype of individuals with one copy of the cystic fibrosis allele?

A

Unaffected

Carriers do not have cystic fibrosis but can pass the allele to their offspring.

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70
Q

What type of disorder is polydactyly?

A

Inherited disorder with extra fingers or toes

Polydactyly can manifest as additional digits on hands or feet.

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71
Q

What type of allele causes polydactyly?

A

Dominant allele (D)

The presence of just one copy of the dominant allele can cause the disorder.

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72
Q

What is the probability of a child having polydactyly if one parent has the dominant allele?

A

50%

If one parent carries one D allele, there is a 50% chance for the child to inherit the disorder.

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73
Q

True or False: The allele for cystic fibrosis is dominant.

A

False

The allele for cystic fibrosis is recessive, meaning two copies are needed for the disorder to manifest.

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74
Q

Fill in the blank: The allele for polydactyly is _______.

A

dominant

This means that only one parent needs to pass on the allele for the child to potentially have the disorder.

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75
Q

What does the Punnett square demonstrate regarding inheritance?

A

Possible inheritance patterns of traits

It helps predict the probability of offspring inheriting specific alleles from their parents.

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76
Q

What is the inheritance pattern of cystic fibrosis?

A

Cystic fibrosis is caused by a recessive allele, f. The dominant allele is F.

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77
Q

What is the chance that a new baby will have cystic fibrosis if both parents are carriers?

A

There is a 25% chance that the new baby will have the disorder and a 50% chance that it will be a carrier.

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78
Q

What are the possible genotypes of the baby in the cystic fibrosis example?

A
  • Unaffected (FF)
  • Carrier (Ff)
  • Have cystic fibrosis (ff)
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79
Q

What is embryo screening?

A

Embryo screening is the process where scientists can remove a cell from each embryo to test for inherited disorders before implantation.

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80
Q

What are some concerns regarding embryo screening?

A

Concerns include ethical implications, potential discrimination against individuals with genetic disorders, and the possibility of selecting for non-health related traits.

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81
Q

What are arguments against embryo screening?

A
  • Suggests people with genetic problems are not wanted
  • Potential for selecting traits like eye or hair color
  • Screening is expensive
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82
Q

What are arguments for embryo screening?

A
  • Helps to stop people suffering
  • Treating disorders costs a lot of money
  • Laws exist to limit its application
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83
Q

Can parents currently select the sex of their baby through embryo screening?

A

No, parents cannot select the sex of their baby unless it is for health reasons.

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84
Q

What is a mutation?

A

A mutation is a random change in a gene.

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85
Q

How do mutations affect genetic variation?

A

Mutations produce genetic variants that can alter an organism’s phenotype.

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86
Q

What is the result of some mutations on an organism’s characteristics?

A

Some mutations can lead to new phenotypes, which may affect how the organism looks or functions.

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87
Q

True or False: Most genetic variants have a significant effect on an organism’s phenotype.

88
Q

Fill in the blank: Variation can be _______.

A

[genetic or environmental]

89
Q

What are the two main types of variation mentioned?

A
  • Genetic variation
  • Environmental variation
90
Q

What is cystic fibrosis?

A

A genetic disorder that affects the respiratory and digestive systems.

Cystic fibrosis is caused by mutations in the CFTR gene.

91
Q

What does it mean to be a carrier of cystic fibrosis?

A

An individual who has one copy of the mutated gene but does not exhibit symptoms of the disorder.

Carriers can pass the mutated gene to their offspring.

92
Q

What is variation within a species?

A

Differences among organisms of the same species.

Variation can occur due to genetic differences and environmental factors.

93
Q

What can cause phenotypic variation?

A

A mixture of genes and the environment.

For example, a plant’s growth can vary based on light availability.

94
Q

What is a mutation?

A

A random change in an organism’s DNA that can be inherited.

Mutations can lead to genetic variants.

95
Q

How frequently do mutations occur?

A

Continuously.

Mutations can happen at any time and are a natural part of genetic variation.

96
Q

What is a genetic variant?

A

A different form of a gene produced by mutations.

Genetic variants can affect phenotypes in various ways.

97
Q

Do most genetic variants affect an organism’s phenotype significantly?

A

No, most have very little or no effect.

Some variants may cause slight changes, while others can lead to new phenotypes.

98
Q

What is an example of a characteristic controlled by multiple genes?

A

Eye color.

Variants in one of the genes may cause slight changes in eye color.

99
Q

What can happen if a mutation leads to a new phenotype?

A

It may make an individual more suited to a changed environment.

Such mutations can become common in a population through natural selection.

100
Q

What role does the environment play in variation?

A

It influences phenotypic traits alongside genetics.

Environmental factors can modify how genes are expressed.

101
Q

True or False: All of a person’s traits are solely determined by their genes.

A

False.

Environmental factors also play a significant role in determining traits.

102
Q

Fill in the blank: A mutation can lead to a _______ phenotype.

A

new

New phenotypes can arise from significant mutations and may provide adaptive advantages.

103
Q

What is the theory of evolution by natural selection?

A

A theory proposed by Charles Darwin stating that organisms with favorable traits are more likely to survive and reproduce.

104
Q

What are the three main components of natural selection?

A
  • Variation in characteristics among organisms
  • Competition for resources
  • Survival and reproduction of the fittest
105
Q

What evidence supports Darwin’s theory of evolution?

A
  • Discovery of genetics
  • Fossil record
  • Antibiotic resistance in bacteria
106
Q

Fill in the blank: New species develop when populations of the same species change so much that they can’t _______.

A

breed with each other to produce fertile offspring

107
Q

What causes extinction of a species?

A
  • Rapid environmental change
  • New predators
  • New diseases
  • Competition with new species
  • Catastrophic events
108
Q

True or False: Natural selection is solely about the survival of the strongest organisms.

109
Q

What is antibiotic resistance?

A

The ability of bacteria to survive and reproduce despite the presence of antibiotics.

110
Q

How do bacteria develop antibiotic resistance? List the steps.

A
  • Bacteria can develop mutations
  • Mutations can lead to resistance
  • New strains of bacteria emerge
  • Resistant bacteria are more likely to survive
  • They pass on the resistance genes
111
Q

Fill in the blank: Over a long period of time, the _______ of organisms can change significantly due to natural selection.

112
Q

What role do fossils play in supporting the theory of evolution?

A

Fossils allow scientists to observe how changes in organisms developed slowly over time.

113
Q

Fill in the blank: Natural selection is about the organisms with the best _______ surviving to pass on their genes.

A

characteristics

114
Q

What is the significance of genetic variants in evolution?

A

Genetic variants produce characteristics that are better adapted to the environment.

115
Q

What happens to antibiotic-resistant bacteria when antibiotics are used?

A

They survive and reproduce, leading to an increase in resistant strains.

116
Q

What is one example of a catastrophic event that can lead to extinction?

A

Volcanic eruption

117
Q

True or False: Evolution can happen rapidly and lead to the immediate formation of new species.

118
Q

What is the relationship between natural selection and the characteristics of organisms?

A

Natural selection favors organisms with characteristics that improve survival and reproduction.

119
Q

Fill in the blank: The sugary nectar in some orchid flowers is found at the end of a long tube to attract _______.

A

moths with long tongues

120
Q

What is antibiotic resistance?

A

The ability of bacteria to resist the effects of antibiotics.

121
Q

How do bacteria become antibiotic-resistant?

A

Through natural selection and changes in their DNA.

122
Q

What happens to bacteria when exposed to antibiotics?

A

Non-resistant bacteria die, while resistant bacteria survive and reproduce.

123
Q

What are the new strains of bacteria that develop resistance called?

A

Antibiotic-resistant strains.

124
Q

What advantage do antibiotic-resistant bacteria have?

A

They can survive in a host being treated for an infection.

125
Q

Fill in the blank: The gene for antibiotic resistance becomes more _______ in the population over time.

126
Q

True or False: Antibiotic-resistant bacteria reproduce more slowly than non-resistant bacteria.

127
Q

What are two reasons why antibiotic-resistant bacteria are a problem?

A
  • There is no effective treatment for the infection.
  • People are not immune to the new strain.
128
Q

Why can antibiotic-resistant strains spread easily between people?

A

Because there is no immunity to the new strain.

129
Q

How quickly can bacteria evolve?

A

Quite quickly, due to their rapid reproduction rate.

130
Q

What is the first step in the process of bacteria becoming antibiotic-resistant?

A

Bacteria undergo changes in their DNA.

131
Q

What is the overall result of antibiotic-resistant bacteria reproducing?

A

Increased population size of the antibiotic-resistant strain.

132
Q

Fill in the blank: The ability to resist antibiotics is a _______ advantage for bacteria.

A

biological

133
Q

What leads to the evolution of bacteria?

A

The passing on of the gene for antibiotic resistance to offspring.

134
Q

What is antibiotic resistance?

A

The ability of bacteria to withstand the effects of antibiotics

Antibiotic resistance is becoming more common due to overuse and incorrect use of antibiotics.

135
Q

What are two reasons antibiotic resistance is worsening?

A
  • Antibiotics are being overused
  • People aren’t using antibiotics correctly
136
Q

What is E. MARA?

A

A relatively common ‘superbug’ that is difficult to eliminate

E. MARA refers to antibiotic-resistant strains of bacteria.

137
Q

When should doctors prescribe antibiotics?

A

Only when absolutely necessary

Antibiotics should not be prescribed for non-serious conditions or infections caused by viruses.

138
Q

Why is it important to take the full course of antibiotics?

A

To ensure all bacteria are destroyed and prevent mutation into antibiotic-resistant strains

139
Q

What is one consequence of using antibiotics in farming?

A

Development of antibiotic-resistant strains of bacteria in the environment

140
Q

What is selective breeding?

A

The process of selecting specific organisms to breed based on desired traits

This method is used to enhance certain characteristics in plants and animals.

141
Q

List the steps involved in selective breeding.

A
  • Select organisms with desired traits
  • Breed them with each other
  • Select the best offspring
  • Continue the process
142
Q

What is a potential issue with selective breeding?

A

It can lead to reduced genetic variation

143
Q

What challenges do drug companies face in developing new antibiotics?

A
  • Slow rate of development
  • High costs of research and production
144
Q

True or False: The rate of development of new antibiotics is keeping pace with the demand for new drugs.

145
Q

What is the worrying thought regarding bacteria that are resistant to all drugs?

A

It may feel like going back to the time before antibiotics were invented

146
Q

Fill in the blank: Selective breeding is a method used to enhance _______.

A

[specific traits in organisms]

147
Q

What can happen if one individual in a selectively bred population has health problems?

A

Health issues may spread throughout the population due to shared alleles

148
Q

What is selective breeding?

A

The process of developing specific traits in plants or animals by choosing which individuals to breed together.

149
Q

What is another term for selective breeding?

A

‘Artificial selection.’

150
Q

What are some examples of traits that can be selected in animals during selective breeding?

A
  • Animals that produce more meat or milk.*
  • Dogs with a good, gentle personality.*
  • Crops with disease resistance.*
  • Decorative plants with big or unusual flowers.*
151
Q

What is the basic process involved in selective breeding?

A
  • Breed selected organisms with each other.*
  • Select the organisms with desired traits.*
  • Select the best offspring and breed them together.*
152
Q

What is a potential advantage of selective breeding?

A

It can lead to organisms with desirable characteristics, such as higher meat yield in cattle.

153
Q

What is a major disadvantage of selective breeding?

A

It reduces the number of different alleles in a population.

154
Q

What is inbreeding in the context of selective breeding?

A

Breeding closely related individuals, which increases the chance of health problems.

155
Q

What health problems can arise from selective breeding?

A
  • Inherited harmful genetic defects.*
  • Increased susceptibility to diseases.*
156
Q

Fill in the blank: Selective breeding can lead to a population being less likely to have alleles that make them _______ to new diseases.

157
Q

How might a farmer selectively breed cattle for increased meat production?

A
  • Select the largest cows and bulls.*
  • Breed them together.*
  • Select the largest offspring for further breeding.*
158
Q

True or False: Selective breeding has been practiced for thousands of years.

159
Q

What happens to a population if one individual is affected by a new disease in the context of selective breeding?

A

The rest of the population is likely to be affected due to lack of genetic diversity.

160
Q

Provide an example of how selective breeding has changed a breed of dog.

A

The domestic dog originated from selective breeding of wolves, leading to breeds like poodles.

161
Q

Explain how you could selectively breed for floppy ears in rabbits.

A

Select rabbits with floppy ears and breed them together, then select the best offspring for further breeding.

162
Q

What is genetic engineering?

A

Changing an organism’s DNA to give it new and useful characteristics.

163
Q

What are genetically modified (GM) crops?

A

Crops that have been genetically engineered for specific traits.

164
Q

Name one benefit of genetically modified crops.

A

Increased resistance to herbicides.

165
Q

How can genetic engineering be applied in agriculture?

A

To make crops resistant to insects, disease, or to improve growth characteristics.

166
Q

What is one example of genetic engineering in medicine?

A

Bacteria genetically engineered to produce human insulin.

167
Q

True or False: Genetic engineering can be used to treat inherited diseases.

168
Q

List three concerns about genetic engineering in animals.

A
  • Hard to predict effects of DNA changes
  • Many genetically modified embryos don’t survive
  • Health problems in modified animals later in life
169
Q

What is a concern about growing GM crops?

A

Potential negative effects on wild flower populations and insects.

170
Q

Fill in the blank: Fossils are the _______ of ancient organisms.

171
Q

What evidence do fossils provide?

A

Information about the history of life on Earth.

172
Q

Describe one method of fossil formation.

A

From gradual mineralization of remains in rock.

173
Q

What can fossils tell us?

A

About the evolution of species over millions of years.

174
Q

How do casts form?

A

When the original organism decays and leaves a mold that fills with minerals.

175
Q

What is one way fossils can be preserved?

A

Through preservation in amber or ice.

176
Q

True or False: All fossils are complete organisms.

177
Q

What do hypotheses about fossils indicate?

A

Various theories about the evolution of life.

178
Q

What is a limitation when studying fossils?

A

Lack of soft tissue preservation.

179
Q

Fill in the blank: Fossils can provide evidence of _______ changes in life forms.

A

[evolutionary]

180
Q

What are fossils?

A

Fossils are the remains of plants and animals that provide information about organisms that lived long ago.

181
Q

How do fossils typically form?

A

Fossils form in rocks in one of three ways:
* Gradual replacement by minerals
* Casts and impressions
* Preservation in places where no decay happens.

182
Q

What is the process of gradual replacement by minerals in fossil formation?

A

Teeth, shells, and bones do not easily decay and can last a long time when buried. When they decay, they get replaced by minerals, forming a rock-like substance shaped like the original hard part.

183
Q

How are casts and impressions formed?

A

Casts and impressions are formed when an organism is buried in soft material like clay, which hardens around it. The organism decays, leaving a cast or impression.

184
Q

What conditions prevent decay in preservation fossils?

A

Decay microbes need oxygen, moisture, warmth, and the right pH to work. In some substances where these conditions aren’t present, like amber, decay doesn’t happen.

185
Q

What are some hypotheses about the origin of life?

A

Hypotheses include:
* First life forms appeared in a swamp or under the sea on Earth
* Simple carbon molecules were brought here on comets and developed into life forms.

186
Q

Why can’t the hypotheses about the origin of life be supported or disproved?

A

There is a lack of valid evidence, as many early organisms were soft-bodied and tend to decay completely, leading to an incomplete fossil record.

187
Q

What geological activities can affect fossils?

A

Geological activities such as the movement of tectonic plates may crush fossils that were already formed in rock.

188
Q

True or False: Fossils can exist millions of years after the organism died.

189
Q

Fill in the blank: Fossils can provide information about how much or how little different organisms have ______ as life has developed on Earth.

A

[changed (evolved)]

190
Q

What types of materials can preserve organisms without decay?

A

Substances like amber, where there is no oxygen or moisture.

191
Q

What is classification in biology?

A

Organising living organisms into groups

Classification helps in understanding the relationships between different organisms.

192
Q

How were organisms classified in the past?

A

Based on their appearance and structures like mitochondria in cells

This method focused on observable traits.

193
Q

What are the five kingdoms in the classification system?

A
  • Animals
  • Plants
  • Fungi
  • Prokaryotes
  • Protists

Each kingdom represents a major category of life forms.

194
Q

Who developed the five kingdom classification system?

A

Carl Linnaeus

Linnaeus is known as the father of modern taxonomy.

195
Q

What are the hierarchical groups in biological classification?

A
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species

These groups help organize living organisms in a structured manner.

196
Q

What advancements have influenced classification systems over time?

A

Improved knowledge of internal processes and advancements in microscopy

These advancements have led to more accurate classification models.

197
Q

What is the three-domain system?

A

A classification system made up by Carl Woese

This system categorizes organisms into three major groups based on genetic evidence.

198
Q

What are the three domains in the three-domain system?

A
  • Eukaryota
  • Archaea
  • Bacteria

Each domain contains organisms with distinct characteristics.

199
Q

What does the Eukaryota domain include?

A

Fungi, plants, animals, and protists

Eukaryota includes organisms with complex cells.

200
Q

What are characteristics of organisms in the Archaea domain?

A

Primitive bacteria that often live in extreme environments

Examples include organisms found in hot springs.

201
Q

What are characteristics of the Bacteria domain?

A

‘True bacteria’

This domain includes a wide variety of bacterial species.

202
Q

What is the binomial system of nomenclature?

A

A two-part naming system for organisms

It includes the genus and species names.

203
Q

In the binomial system, what does the first part represent?

A

The genus

The genus groups species that are closely related.

204
Q

In the binomial system, what does the second part represent?

A

The species

This identifies the specific organism within the genus.

205
Q

True or False: The more recent the evolutionary traits, the more closely related the organisms are.

A

True

Evolutionary traits indicate common ancestry.

206
Q

What do scientists look for when studying evolutionary traits?

A
  • Living organisms
  • Extinct organisms

This helps in understanding the evolutionary history of species.

207
Q

What is the first part of a binomial name called?

A

Genus

The genus indicates the group to which the organism belongs.

208
Q

What does the second part of a binomial name represent?

A

Species

The species identifies the specific organism within the genus.

209
Q

In the binomial name ‘Homo sapiens’, what does ‘Homo’ refer to?

A

Genus

‘Homo’ indicates the group of human species.

210
Q

In the binomial name ‘Homo sapiens’, what does ‘sapiens’ refer to?

A

Species

‘sapiens’ specifies the particular species of humans.

211
Q

What do evolutionary trees illustrate?

A

Relationships among species

They show common ancestors and how species are related.

212
Q

How do scientists determine relationships between extinct species?

A

Fossil record

Information from fossils helps scientists understand extinct species’ relationships.

213
Q

What is the significance of a more recent common ancestor in evolutionary trees?

A

Species are more closely related

The closer the common ancestor, the more characteristics species are likely to share.

214
Q

True or False: Whales and dolphins are distantly related to sharks.

A

True

Whales and dolphins share a recent common ancestor, making them closely related, while sharks are more distantly related.

215
Q

Complete the statement: The binomial system uses _______ to classify organisms.

A

Latin names

This system ensures each species has a unique and universally accepted name.

216
Q

What happens to the genus in a binomial name when abbreviated?

A

It is abbreviated to a capital letter followed by a full stop

This helps simplify the scientific name while retaining clarity.

217
Q

What do extinct species refer to?

A

Species that don’t exist anymore

These are organisms that have no living representatives.