Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Genetic theory > Flashcards

Genetic theory Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Nucleic acid

A

polynucleotide macromolecule eg: DNA and RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Non-nuclear DNA

A
  • found in mitochondria or chloroplast

- role: allows organelles to reproduce without a nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Heredity

A

the passing of features from parents to offspring by means of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Species

A

Group of similar organisms capable of interbreeding to produce fertile offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Non-coding DNA

A

DNA which does not code for a protein also known as “Junk DNA”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Codon

A
  • Three bases in a sequence
  • Each codon codes for an amino acid
  • During protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Gene expression

A

The way in which the genetic code in a gene is decoded and used to make a protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Gene

A
  • Collection of codons
  • Contains the genetic code to form a protein
  • Controls a particular characteristic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Genetic screening

A

Test to establish the presence or absence of a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Outline the procedure for Genetic screening

A
  1. “DNA probe” is added to a DNA sample with a gene taken from the person being tested.
  2. DNA probe only attaches to the normal gene.
  3. DNA that does not attach is the altered gene.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name the 2 scientists that described the DNA structure

A

Watson and Crick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does DNA stand for?

A

Deoxyribonucleic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where is DNA located

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the shape of DNA

A

Double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the basic building block of DNA

A

The nucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does nucleotide consist of

A
  1. Phosphate
  2. Sugar
  3. Nitrogen base
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name the 4 types of bases

A
  1. Adenine
  2. Guanine
  3. Thymine
  4. Cytosine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How are the 2 strands held together?

A

Hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are complementary base pairs?

A

Each base has a corresponding matching base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many hydrogen bonds are between adenine and thymine? Guanine and Cytosine?

A
  1. 2 hydrogen bonds

2. 3 hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are these bases classified as?

  1. Adenine and Guanine
  2. Thymine and Cytosine
A
  1. Purines

2. Pyrimidines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Function of DNA

A
  1. Carries and passes on genetic information from parents to offspring in the form of genes
  2. Bacteria has one chromosome composed of DNA only
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the nature of the genetic code

A
  1. A codon is 3 bases in a sequence
  2. Each gene codes for one amino acid
  3. Gene consists of a collection of codons that collectively code for one protein
  4. mRNA copies the genetic code from DNA and brings it to the ribosome in the cytoplasm where protein synthesis occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Define DNA replication

A

DNA makes exact copies of itself which are passed on from one generation to the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Name the 2 main stages of DNA replication

A
  1. Opening of DNA double helix

2. The synthesis of complementary nucleic acid strands alongside the existing strands to form two identical helices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Outline the account for DNA replication

A
  1. DNA replication occurs during the interphase of cell division and involves making an exact copy of DNA
  2. Hydrogen bonds between the base pairs break down
  3. The two strands separate
  4. Each DNA acts as a template to form a new complementary strand
  5. DNA nucleotides from the cytoplasm move into the nucleus and match up with their corresponding nucleotide on the exposed DNA strands
  6. Two exact copies of DNA are made called helices
  7. Each new double-strand rewinds to form a double helix
  8. This process requires energy from ATP and the anabolic enzyme DNA polymerase which is a catalyst to assemble DNA nucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does RNA stand for

A

Ribonucleic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How are the DNA and RNA similar?

A
  • Both nucleic acids

- Both contain the bases Adenine, Guanine and Cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How do DNA and RNA differ from one another?

A 
DNA
- Double Helix
- Sugar
- Base (Thymine)
- Location: Nucleus
RNA 
- Single strand
- Ribose
- Uracil
- Location: nucleus and cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Name the 3 types of RNA

A
  1. rRNA- ribosomal RNA
  2. mRNA- messenger RNA
  3. tRNA- transfer RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe rRNA

A
  1. Forms the ribosomes

2. Holds mRNA in place at the ribosome during protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe mRNA

A
  1. Transcribes the genetic code from DNA

2. mRNA carries this code to the ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe tRNA

A
  1. Transfers amino acids to mRNA at the ribosome
  2. It attaches to its complementary mRNA codon placing its amino acid in the correct sequence within the protein
  3. tRNA has an amino acid attached at one end and anticodon three exposed bases at the other end of the molecule: the anticodon is complementary to mRNA codon
34
Q

Each mRNA codon specifies one of three possible outcomes during protein synthesis. Name these three possible outcomes

A
  • Start codon
  • Codon which assembles an amino acid
  • Stop codon
35
Q

Describe the method to isolate DNA from onion tissue

A
  1. Chop onion into small pieces (To disrupt the structure and release cytoplasm when the cell wall is broken down)
  2. Add chopped onion to salt and washing up liquid (Salt clumps DNA and washing up liquid breaks down cell membranes)
  3. Warm beaker in a water bath at 60C for 15 minutes (Denatures enzyme)
  4. Cool beaker by placing beaker in an ice water bath for 5 minutes (allows DNA to break down)
  5. Blend for 3 seconds (Breaks down cell wall and releases DNA)
  6. Filter mixture
  7. Transfer 10cm of the filtrate to a test tube and add 2-3 drops of protease (Breaks down protein around DNA)
  8. Collect DNA - ice-cold ethanol
    - DNA is insoluble in ice-cold ethanol
    - Use a glass rod to collect DNA (clear)
    - If white mesh DNA has protein
36
Q

List the steps of how DNA profile is made

A
  1. DNA is extracted
  2. Restriction enzymes are used to cut DNA into fragments
  3. Separating DNA fragments according to size by electrophoresis
  4. The band pattern or profile is analysed
37
Q

Name 2 applications of DNA profiling

A
  1. Forensic science (crime scene)

2. Medical (establish biological parents of any child)

38
Q

Explain what is meant by the term DNA profiling

A

Making unique pattern of bands from the DNA of a person which can be used to distinguish that DNA from another DNA for comparison purposes

39
Q

What is meant by genetic screening

A

Test to establish the presence or absence of genes

40
Q

Name stage 1 of Protein synthesis and describe

A
  1. Initiation
    - DNA double helix unwinds
    - Enzymes break the hydrogen bonds
    - One DNA strand the transcribing DNA strand is used as a template to form a complementary molecule of mRNA
41
Q

What is meant by Transcription

A

Copying of a sequence of genetic from a single strand of DNA onto mRNA

42
Q

Name stage 2 of Protein synthesis and briefly explain

A
  1. Transcription
    - Occurs in the nucleus
    - RNA nucleotide bases bond with one single strand of exposed DNA
    - DNA strand acts as a template
    - RNA polymerase assembles the RNA nucleotide to form mRNA
    - mRNA has a series of bases that are complementary to those on the transcribing DNA strand
    - mRNA moves to the cytoplasm and attaches to a ribosome
    - Each ribosome is made up of ribosomal RNA and protein
    - rRNA holds mRNA in place at the ribosome
43
Q

What is meant by Translation

A

Conversion of a sequence of genetic bases on mRNA into a sequence of amino acids

44
Q

Name the 3rd stage of Protein synthesis and briefly explain

A

Termination

  • Occurs in Ribosome
  • tRNA each with an amino acid attached is attracted by their anticodons to mRNA codons
  • The first tRNA molecule attaches to mRNA
  • Amino acids are aligned in a sequence determined by the codon sequence of the mRNA
  • Aligned amino acids bond to form the peptide links of the new protein
  • Protein formed folds into its correct shape
45
Q

Define Genetic engineering

A

Artificial manipulation or alteration of genes

46
Q

Genetically modified organisms

A

Organisms that have genes from other species inserted into them

47
Q

Define Clone

A

Genetically identical organisms

48
Q

Define Recombinant DNA

A

Two different species combined

49
Q

Tools required for genetic engineering

A
  1. Source of DNA
  2. Restriction enzymes (Cut human DNA into fragments)
  3. Cloning vector (Plasmid will accept and carry foreign DNA)
  4. DNA ligase (Enzymes used to join DNA from 2 different species firmly together)
50
Q

List the stages involved in Genetic Engineering

A
  1. Isolation
  2. Cutting
  3. Insertion and ligation
  4. Transformation
  5. Cloning
  6. Expression
51
Q 
In genetic engineering all or some of the following procedures may be involved
-Isolation
-Cutting 
-Transformation 
-Introduction of base sequence changes 
-Expression
Briefly explain each
A 
- Isolation
removal of target gene
-Cutting 
Human DNA using restriction enzymes
- Transformation 
Uptake of recombinant DNA by the bacterial host cell
- Introduction of base sequence change
order of bases in the host DNA 
- Expression
Activation of an inserted gene to produce the product
52
Q

Give one application of genetic engineering in any two of the following

  1. An animal
  2. A plant
  3. A micro-organism
A
  1. An animal
    - Sheep produce a protein to treat emphysema (Collapse of the alveoli)
  2. A plant
    - production of herbicide-resistant crops
  3. A micro-organism
    - Production of insulin
53
Q

Define what is meant by Variation

A

The differences in the characteristics of a species are due to differences in the genotype and the effect on the environment

54
Q

Name 2 types of Variation

A
  1. Acquired variation

2. Inherited/Genetic variation

55
Q

Describe the two types of Variation

  1. Acquired
  2. Inherited
A
  1. Acquired
    - Not genetically controlled
    - Not inherited
  2. Inherited/genetic variation
    - Genetically controlled by genes
    - Passed on to offspring
56
Q

What is the significance of inherited variation in the evolution of a species?

A
  • Produces new genotypes

- Allows natural selection to occur

57
Q

Causes of variation

A
  • Sexual reproduction

- Mutations

58
Q

Define Mutation

A

Change in the structure or amount of DNA

59
Q

What is meant by Gene mutation

A

Change in a single gene

60
Q

What is meant by a chromosome mutation

A

Change in the structure or number of chromosomes

61
Q

Causes of mutations

A

mutagens

62
Q

Define spontaneous mutations

A

Errors during DNA replication so that the DNA doesn’t make the exact copies of itself

63
Q

What are mutagens

A

Agents that cause mutations

64
Q

Name examples of mutagens

A
  • Radiation

- Chemicals

65
Q

What is meant by somatic cell mutations

A

Benign tumours

66
Q

Name an example of a Gene Mutations

A

Sickle cell anaemia

67
Q

What is sickle cell anaemia caused by

A

Change in the base of the haemoglobin

68
Q

What are the symptoms of sickle cell anaemia

A

Fatigue

Clumping of red blood cells

69
Q

Treatment for sickle cell anaemia

A

Blood transfusion

70
Q

Name other conditions caused by gene mutations

A
  • Cystic fibrosis
  • Haemophilia
  • Albinism
71
Q

Name an example of Chromosome mutation

A

Down’s syndrome

72
Q

What does down’s syndrome result from

A

Extra chromosome 2n=47

73
Q

What does downs syndrome result in

A
  • Alteration in facial features
  • Reduced IQ level
  • Reduced resistance to disease
74
Q

What is meant by evolution?

A

living things change genetically to produce new forms of life over periods of time

75
Q

Define natural selection

A

Organisms have genetically controlled characteristics that allow them to adapt to their environment so they will survive and pass on their genes

76
Q

Theory of Natural Selection was developed by…

A

Charles Darwin and Alfred Wallace

77
Q

Account of the theory of Natural Selection

A
  1. Observation 1:
    - Overbreeding
  2. Observation 2:
    - Population num remains constant
  3. Conclusion 1:
    - Struggle for existence
  4. Observation 3:
    - Inherited variations
  5. Conclusion 4:
    - Natural selection
78
Q

In the context of natural selection, explain how numbers in a population remain collectively constant despite the production of many offspringing

A
  • Competition
  • Best adapted survive
  • Death rate equals reproduction rate
79
Q

Give an account of Theory Selection. Name the scientists who are associated with the theory and refer to one observation that prompted its development

A 
Scientists: Darvin and Wallace 
Observation: 
1. Large number of offspring
2. Low survival so population remains constant 
3. Variation in offspring
80
Q

Evidence of evolution

A
  1. Paleontology
  2. Comparative anatomy
  3. Comparative embryology
81
Q

Give one example of evidence for evolution and briefly describe

A
  1. Paleontology- a study of fossils
    - Fossil is the remains of an ancient organism
    Fossil evidence indicates:
    - Fossils can be aged
    - Modern fossils show increased complexity
    - Fossils show changes when compared
    - Changes can be linked to environmental change
82
Q

Evolution of a horse

A
  • Have grown in size
  • Have evolved about 60 million years ago
  • Horses used to be 0.4 metres tall
  • Now they are 1.6m tall

Biology (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions