B5 Flashcards
(82 cards)
1
Q
Who did the father of genetics
A
Mendel
2
Q
What’s a genotype
A
The alleles for a gene
3
Q
What’s a phenotype
A
The physical appearance of the genes
4
Q
What’s a gene
A
Controls a characteristic
5
Q
What’s an allele
A
Different forms of a gene
Eg: tall gene and short gene
6
Q
What does a dominant allele mean
A
Only have to be present in 1 chromosome to be expressed
7
Q
What does a recessive allele mean
A
Must be present in both chromosomes to be exposed
8
Q
When using a punnet square do you use two different letters for different alleles?
A
NO, you always use the capital of a letter for dominant and a lower case of the same letter for the recessive allele. Even if the name of the two allele start with different letters
9
Q
What does homozygous mean
A
Two copies of the same gene
For example two dominant Allele
10
Q
What does heterozygous mean
A
Two different genes
For example Tt, dominant allele and recessive allele
11
Q
Is mitosis sexual or A sexual
A
Asexual
12
Q
What is meiosis useful for
A
Producing gametes
13
Q
Is meiosis asexual or sexual
A
Sexual
14
Q
What does MEIOSIS produce
A
4 genetically different haploid cells
15
Q
What does MITOSIS produce
A
2 genetically identical cells
16
Q
What is mitosis used for
A
Used for growth and repair
Used by bacteria (binary fission) and humans
17
Q
What organisms use both mitosis and meiosis to reproduce
A
Strawberries and fungi
18
Q
How do plants carry out sexual reproduction
A
Egg + pollen grain = seed
19
Q
What reproduction is slower mitosis or meiosis and why
A
Meiosis is because the cell have to split to make 4 daughter cells
20
Q
Where are chromosomes located
A
Nucleus
21
Q
What are chromosomes made of
A
Tightly compacted strips of DNA
22
Q
What is DNA
A
A Polymer twisted into a double helix shape
23
Q
What is the genome
A
The entire genetic make up of an organism
24
Q
What was the human genome project
A
The sequencing of a human genome
We have 21,000 genes
25
Humans have also sequenced the genome of bacteria, why is this useful?
Helps us understand the causes of communicable diseases so we can make cures
26
What’s the positives of coding the human genome
Helps us understand inherited diseases the find the cure
Tracing genomes away from common ancestors - understand how humans reviled into different races
27
What is polydactyl
When someone has extra toes and fingers
28
What is polydactyl caused by
A dominant allele
29
Can polydactyl be detected
Yes , through prenatal screening but it cannot be prevented or cured
30
What is cystic fibrosis caused by
The mutation of proteins that are responsible for the production of mucus
31
What is cystic fibrosis
The production of thick and sticky mucus that blocks airways
32
Why can curatif fibroids cause deadly infections
The mucus traps bacteria that goes down the airways, because the musc is too thick to be taken to the oesophagus to be digested the bacteria and mucus stays there. The bacteria then release toxins to cause infections
33
What’s another word for thickness of mucus
Viscosity of mucus
34
What two types of prenatal screening can be used to find polydactyl
Amniocentesis and chorionic villus
35
How does cycstic fibrosis affect the digestive system
The thick mucus clogs the pancreatic duct, meaning most digestive enzymes can not travel to the small intestine to aid in dispersion
35
What’s two symptoms of cycstic fibrosis
Difficulty breathing
Difficulty gaining weight
36
What allele is cystic fibrosis caused by
Recessive
37
A couple is planning to have a baby but they know their child has a risk of being born with a genetic disorder, what can they do to check?
IVF. The DNA in the sperm/ egg will be checked for genetic disorders
38
Why do screening procedures take place later on in pregnancy
To lower the risk of any damage or harm to the foetus
39
What is Amnicentesis
The process of taking the amniotic fluid surrounding the developing foetus to scan the fluids DNA for genetic issues
40
If pregnancy has already occurred how can you screen for genetic disorders
Use a needle to extract cells from the placenta or amniotic fluid.
Analyse the cells DNA for the genetic disorders
41
At all times the needle is monitored by an ultrasound
True or false
True
42
Positives of screening for genetic disorders
Money saved by not treating individuals with disorders who have been aborted
Laws are in place to prevent screening for undesirable conditions
If termination occurred child and parents would avoid a potentially poor quality of life
43
Negatives of screening for genetic disorders
Screening is expensive
Prejudice may occur and people with genetic disorders will feel unwanted or rejected by society as people are screening against their disorder
Embryo has a right to life
Screening can damage healthy individuals and lead to miscarriage
44
What is variation caused by
Continuous mutations in the DNA
45
What is a species
A group with organisms with similar characteristics that can breed together to create fertile offspring
46
What influences an animals ability to interbreed
Wether or not they have the same amount of haploid chromosomes
47
The environment does not affect variation
True or false
False
48
What characteristics are a result of your environment and genetics
Height and weight
49
What characteristics are a result of your environment
Tans accent scars
50
You are asked a question on natural selection. What points do you mention?
⭐️Variation exsusts in the population
⭐️We have different characteristics due to DNA mutation
⭐️Advantageous characterises help a population survive
⭐️Survivors have a higher chance of reproducing
⭐️Offspring may inherit advantageous characteristics
⭐️Frequency of the characteristic in population increases over time
51
Why are twins useful for studying variation caused by environment
They have the same genotype
52
What is natural selection
The process in which desirable characteristics are passed onto future generations and kept within a population for enhanced survival
53
How have ancestorial horses developed to become modern horses
Ancestorial horses had 5 toes that can spread to avoid sinking in marsh areas(they used to live in a marsh forest) - Morden day horses have 1 hoof they helps them run on grass land
Ancestorial horses were short so they would not be entangled in low lying canopies- modern day horses are taller with longer legs so the can run faster and they have no need to worry about low lying canopies
54
What is selective breeding
Humans artificially select the animals or plants with desirable characteristics to be bred together to keep that characteristic in the population
55
What’s a problem of selective breeding
Inbreeding- Severely reduces the variety of genes - could leave organisms prone to diseases
For example inbreeding in dogs leads to some of them having leg issues, breathing difficulty’s and epilepsy
56
How have farmers used selective breeding
To improve meat and milk yields
57
Farmers have used selective breeding on cows to increase milk and meat yields. What’s a disadvantage
Cows produce 6x more milk than a calf needs/ this lead to mastitis where glands can get infected Or cows can have difficulty walking from the weight of excess milk
58
Why do humans selectively breed plants
To produce disease resistant crops
Brightly coloured folders for aesthetic purposes
59
What is genetic engineering
Modifying the genome of an organism by introducing a gene from another
60
Why might a farmer decide to have a genetically modified glow in the dark crop
This crop glows when bitten by insects
This alerts the farmer so they only spray incepticides when nessecary, reducing the amount of chemical usage
61
Why is too much inceptiside usage on a crop undesirable
It kills vital insects as well as the bad
No one wants a lot of chemicals in their food
62
Negativesof GM crops
May affect food chain if insects are killed
What is the gene made it into another species
What if there is a mutation and the food becomes dangerous to eat
63
Positives of GM crops
Increases yield of crops
No problems so far
Some GM plants produce a poison when bitten that kills bugs for good
64
Why are animals also genetically modified
So they produced neutering filled food
Sheep can be modified to produce growth hormones in their milk
Animals modification must be dont at the fertilisation stage
65
What is a recombinant plasmid
A plasmid that contains the DNA of two organisms
66
How is a bacterial cell modified to create human insulin
Insulin producing cell taken from pancreas
Insulin gene cut out using enzymes
Plasmid in bacteria cut open
Insulin gene implanted in the plasmid
Bacterial cells spilt and makes insulin
Insulin collected and purified
Injected into patient
67
What’s two positives and a negative of bacteria producing insulin
Positive
- low side effects
- more drug supply
Negative
- only works with bacteria that can produce insulin
68
What’s a fossil
The remains of impression of a plant or animals that lived millions of years ago
69
Some animals do not have a complete fossil record
Why is this
They were soft tissues and easy to decompose so they cannot fossilise
69
Why can you use bacteria to watch real time evolution
They reproduce very quickly
69
How do fossils formed
When an animals dies it’s covered by sediment
As the malheurs of sediment increase the decomposing organisms are d’épreuves of the oxygen they need to feel
No decomposition takes place
Over time minerals replace the bone turning the skull into stone
70
What increases the frisk of bacteria becoming antibiotic resistant
Over use of antibiotics
Not finishing the course of anti biotic
Agricultural use
Poor hygiene in hospital
71
What’s an example of a resistance bacteria
MRSA
methicillin resistance staph aureus
72
Why do animals becoming extinct
New predators
New disease
New competitor
Climate change
73
How many kingdoms are there
6
74
What are the different classification and what is the mnemonic
King Philip Came Over From Great France
Kingdom
Phylum
Class
Order
Family
Genus
Species
75
How are animals classified
By anatomical similarities
76
How to create binomal name
Genus + species = Binomal name
77
What are the three domains
Bacteria - single celled no nucleus
Archea- single cells prokaryotic organisms - live in extreme environments
Eukarya- complex and have a nucleus can be single celled or multi celled
78
What scientist created binomial classification
Carl Linnaeus
79
What scientist developed the three domains system
Carl woese
