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sarah's biology class > inheritance, variation and evolution > Flashcards

inheritance, variation and evolution Flashcards

1
Q

Types of Cell Division:

A

Types of Cell Division:

Mitosis

Meiosis

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2
Q

what are gametes and what are some examples?

A

gametes are sex cells e.g. egg/sperm cell, pollen

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3
Q

In sexual reproduction, male and female gametes _____.

A

In sexual reproduction, male and female gametes fuse.

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4
Q

Mitosis
Two genetically ________ daughter cells

Meiosis
____ genetically __________ daughter cells

A

Mitosis
Two genetically identical daughter cells

Meiosis
Four genetically non-identical daughter cells

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5
Q

Asexual reproduction

A

Asexual reproduction

Divide by mitosis

No gamete fusion

One parent

Offspring are clones

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6
Q

Asexual reproduction is common in …?

A

Asexual reproduction is common in single-celled organisms(e.g. bacteria) and some plants.

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7
Q

Division of cells by meiosis (or meiotic division) in reproductive organs produces _______ with ____ the number of chromosomes found in all other body ____.

A

Division of cells by meiosis (or meiotic division) in reproductive organs produces gametes with half the number of chromosomes found in all other body cells.

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8
Q

stages of meiosis

A

Cells split

Each cell has a pair of each chromosome (diploid cell).
During meiosis each pair of chromosomes replicate and the cell splits in two.

Further cell splitting

There are now two identical cells.
The diploid cell divides again.

Haploid cells created

This creates four genetically different gametes that each have half the number of chromosomes of the parent cell. Cells that have only one copy of each chromosome (such as gametes) are called haploid cells.

Gametes fertilise

During sexual reproduction, the male gamete fertilises the female gamete and the fertilised cell now has the normal number of chromosomes (46 in humans).

Mitosis

Once the gametes have combined, the new cell divides by mitosis (the cell grows asexually).
As soon as the embryo reaches a certain size, cells begin to differentiate (specialise).

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9
Q

what can sometimes reproduce both sexually and asexually:

A

what can sometimes reproduce both sexually and asexually:

1
Fungi
2
Malaria parasites
3
Strawberry plants
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10
Q

An advantage of sexual reproduction is …

A

An advantage of sexual reproduction is variation in the offspring, increasing the chances of a population being able to survive environmental change by natural selection.

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11
Q

If an organism can reproduce sexually or asexually, it often reproduces _______ when conditions are good.

A

If an organism can reproduce sexually or asexually, it often reproduces asexually when conditions are good.

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12
Q

asexual reproduction is _______ than sexual reproduction

A

asexual reproduction is faster than sexual reproduction

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13
Q

What are the 4 genetically different gametes produced during sexual reproduction called?

A

What are the 4 genetically different gametes produced during sexual reproduction called?

haploid cells

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14
Q

The three levels of organisation of a genome:

A

The three levels of organisation of a genome:

DNA (smallest)

genes

chromosomes (biggest)

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15
Q

The genome is the entire (all) genetic ________ of an organism.

A

The genome is the entire (all) genetic material of an organism.

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16
Q

The nucleus of eukaryotic cells contains chromosomes made of DNA _________.

Each chromosome contains a large number of _____.

Each gene tells how a specific _______ should be made.

A

The nucleus of eukaryotic cells contains chromosomes made of DNA molecules.

Each chromosome contains a large number of genes.

Each gene tells how a specific protein should be made.

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17
Q

Contain lots of genes.

The human body contains 23 pairs of these and one of each pair comes from each parent.

A

Chromosomes

Chromosomes contain lots of genes. The human body contains 23 pairs of chromosomes and one of each pair comes from each parent.

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18
Q

This is a small section of DNA.

They code for a sequence of amino acids, which combine to make a specific protein.

A

Gene

a gene is a small section of DNA. genes code for a sequence of amino acids, which combine to make a specific protein.

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19
Q

This is a polymer (a chemical made by taking a group of molecules and repeating them many times) made up of two strands forming a double helix shape.

A

DNA is double helix polymer, which means it is a polymer (a large molecule made up of many subunits) made up of two strands forming a twisted, ladder shape.

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20
Q

A gene is a _____ of DNA. There are about 300 genes in the smallest human chromosome.

A

A gene is a segment of DNA. There are about 300 genes in the smallest human chromosome.

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21
Q

When was the Human Genome Project completed?

A

2003

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22
Q

Genome sequencing may help us to identify and cure _____ diseases in the future.

A

Genome sequencing may help us to identify and cure genetic diseases in the future.

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23
Q

How could the completion of the Human Genome Project, and subsequent research on the human genome, be beneficial in tackling Cystic Fibrosis?

A

How could the completion of the Human Genome Project, and subsequent research on the human genome, be beneficial in tackling Cystic Fibrosis?

The knowledge we have gained from the Human Genome Project and subsequent research can help us in identifying Cystic Fibrosis genes, allowing those carrying it to be made aware.

It could also further our understanding of the disorder and how we should be treating it.

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24
Q

The Human Genome Project has advanced our knowledge, which should lead to … (3)

A

better investigations into human evolutionary history

identification of genes linked to disorders

improved understanding of inherited disorders

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25
Protein synthesis is ...
Protein synthesis is how our bodies make proteins.
26
Each amino acid is coded for by a specific sequence of three bases, called a ______. The order of the bases on the DNA impacts the order in which amino acids are combined to form _______. Changing the sequence of bases can change the ______ made by a gene.
Each amino acid is coded for by a specific sequence of three bases, called a codon. The order of the bases on the DNA impacts the order in which amino acids are combined to form proteins. Changing the sequence of bases can change the protein made by a gene.
27
During protein synthesis, specific amino acids are delivered by _________ molecules to the protein chain.
During protein synthesis, specific amino acids are delivered by carrier molecules to the protein chain
28
If the order of bases on DNA changes, what happens to the proteins made using the DNA?
the amino acid sequence may change
29
stages of protein synthesis
a template is taken from the DNA and leaves the nucleus the template is used to guide protein synthesis on ribosomes located in the cytoplasm specific amino acids are delivered by carrier molecules to the protein chain, where they are added in the order shown on the template once completed the long protein chain molecule folds up giving it a unique structure
30
A mutation is a change in the _________ sequence of DNA.
A mutation is a change in the nucleotide sequence of DNA.
31
__________ is often disadvantageous, but can bring advantages (a mutation may give a survival advantage, such as resistance to an antibiotic in bacteria.)
mutations is often disadvantageous, but can bring advantages (a mutation may give a survival advantage, such as resistance to an antibiotic in bacteria.)
32
In most cases, a characteristic results from ________ genes interacting. However, sometimes, a single gene is responsible for a characteristic. such as red-green colour ________.
In most cases, a characteristic results from multiple genes interacting. However, sometimes, a single gene is responsible for a characteristic. such as red-green colour blindness.
33
If an individual possesses the genotype BB, we would say they were:
If an individual possesses the genotype BB, we would say they were: homozygous dominant
34
If a person has two alleles the same, we say that they are:
If a person has two alleles the same, we say that they are: homozygous
35
If the allele for a free earlobe is E (dominant) and the allele for an attached earlobe is e (recessive), what will the earlobe of a person with the genotype Ee be like?
If the allele for a free earlobe is E (dominant) and the allele for an attached earlobe is e (recessive), what will the earlobe of a person with the genotype Ee be like? The person is heterozygous. This means that the dominant trait will be observed, and so their earlobe will be free. This assumes that the environment has not interfered.
36
A ________ allele is always expressed, regardless of what the other allele is. It only needs one copy to be expressed (to be in) a person.
A dominant allele is always expressed, regardless of what the other allele is. It only needs one copy to be expressed (to be in) a person.
37
Some regions of DNA do not _______ protein sequences. The term given to these sections is non-coding DNA. Non-coding DNA often plays a role in gene __________. Therefore, mutations that arise here may result in genes being switched on or off.
Some regions of DNA do not encode protein sequences. The term given to these sections is non-coding DNA. Non-coding DNA often plays a role in gene expression. Therefore, mutations that arise here may result in genes being switched on or off.
38
Cystic fibrosis is a disorder of cell _________. It is caused by a ________ allele. Cystic fibrosis causes thick, sticky mucus to build-up in the ____ and digestive system.
Cystic fibrosis is a disorder of cell membrane. It is caused by a recessive allele. Cystic fibrosis causes thick, sticky mucus to build-up in the lungs and digestive system.
39
If a sufferer of cystic fibrosis has non-suffering parents, what are the parents?
If a sufferer of cystic fibrosis has non-suffering parents, what are the parents? heterozygotes
40
People can now have their ________ screened to look for genes that cause the individual to be more susceptible to genetic disorders.
People can now have their genome screened to look for genes that cause the individual to be more susceptible to genetic disorders.
41
Potential disadvantages of embryonic screening:
The embryos that are not used are destroyed. This can be considered unethical or against religious views. If mismanaged, this technology could become a way for parents to select the most desirable embryo as their child-to-be. expensive, ethics etc.
42
Advantages of embryonic screening:
financial savings IVF embryos prevent suffering
43
The combination of chromosomes in a female are:
The combination of chromosomes in a female are: XX
44
Variation can be a result of:
Genetics The environment
45
When speciation happens:
When speciation happens: fertile offspring are not produced when different individuals are bred together different species are formed
46
Evolution is the gradual change of the inherited characteristics of ________ populations over time.
Evolution is the gradual change of the inherited characteristics of biological populations over time.
47
How can mutations lead to human evolution?
How can mutations lead to human evolution? Most mutations (permanent changes in nucleotide sequences of DNA) do not affect the phenotype. But if a mutation creates a new phenotype that is better adapted to environmental changes (than the rest of the population), the mutation is likely to spread throughout the population over a small number of generations. For example, over time the size of the human brain has increased, as those born with a bigger brain were found to be at a survival advantage.
48
phenotype is the organisms __________ appearance
phenotype is the organisms physical appearance
49
Natural Selection
within a biological population, different individuals display genetic variation individuals possessing genes that make them better adapted to the environment will have a greater chance of survival individuals with the best chances at survival will most likely breed successfully. the characteristics that make individuals more likely to survive will be passed on to the next generation.
50
Speciation happens when the average phenotypes of two populations have _______ (changed) so much that it is no longer possible for individuals from two different populations to _______ to produce ______ offspring. Two different species have been formed. Speciation happens as a result of ________.
Speciation happens when the average phenotypes of two populations have diverged (changed) so much that it is no longer possible for individuals from two different populations to interbreed to produce fertile offspring. Two different species have been formed. Speciation happens as a result of evolution.
51
Organisms that have been selectively bred for their useful characteristics include:
Organisms that have been selectively bred for their useful characteristics include: ``` 1 Crops 2 Farm animals 3 Dogs 4 Flowers ```
52
Potential problems caused by selective breeding include:
reduced variation (differences in characteristics) within a population, making it harder for a species to adapt to environmental change. Selective breeding can lead to inbreeding. Here, some breeds become particularly susceptible to disease or inherited defects. For example, French bulldogs have been selectively bred to have flat faces, but that causes them breathing problems.
53
Name the organisms that have the following favourable characteristics for selective breeding: Crops Flowers Farm animals Dogs
Name the organisms that have the following favourable characteristics for selective breeding: Crops Disease resistance Flowers Visual features, such as colour and size Farm animals Produce more meat or dairy to increase yield Dogs Docile-nature (easily taught or handled)
54
Genetic engineering involves:
introducing a gene from a another organism modifying an organisms genome
55
Genetic engineering involves modifying (changing) an organism’s genome by introducing a gene from another organism to produce a desired ___________.
Genetic engineering involves modifying (changing) an organism’s genome by introducing a gene from another organism to produce a desired characteristic.
56
Structures cut by enzymes in genetic engineering:
gene vector
57
Genetic engineering happens like this:
Cut the gene out (Enzymes are used to “cut” a desired gene out of a chromosome.) Cut a vector (The same enzyme is used to “cut” a vector. The Vector is usually a bacterial plasmid (loop of DNA) or virus.) ``` Gene inserted (The vector is used to insert the gene into the required cells.) ``` Delivering gene If the gene is delivered into cells before they have differentiated (at the egg or embryo stage), all cells in the developed organism will have the gene and show the characteristic.
58
Examples of genetic engineering:
Examples of genetic engineering: 1 Insulin production 2 Vitamin A rich rice
59
Name the three types of organism that genes can be transferred into with genetic engineering:
Name the three types of organism that genes can be transferred into with genetic engineering: Bacteria Plants Animals
60
In most cases, the yield of genetically modified crops is greater than the yield of _______ crops.
In most cases, the yield of genetically modified crops is greater than the yield of normal crops.
61
Some people expect GM (genetically modified) crops to negatively impact wild flower and insect populations, thus reducing _________.
Some people expect GM (genetically modified) crops to negatively impact wild flower and insect populations, thus reducing biodiversity.
62
Genetic engineering advantages
Genetic engineering advantages Golden rice Preventing inherited diseases Higher yields
63
Genetic engineering disadvantages
Genetic engineering disadvantages Reduced biodiversity Superweeds Ethical concerns
64
Why might we want to genetically modify plants?
Why might we want to genetically modify plants? To make plants resistant to diseases, insects, or herbicides. For example, the majority of the corn grown in the US is genetically modified to be resistant to herbicide glysophate, which is used to kill weeds. To let us produce larger or ‘better’ fruits.
65
Since genetic engineering is a relatively recent development, it is uncertain what the long-term _____ may be.
Since genetic engineering is a relatively recent development, it is uncertain what the long-term effects may be.
66
Animals can be cloned using _____ transplants and adult cell cloning. Plants can be cloned using cuttings or _______ culture.
Animals can be cloned using embryo transplants and adult cell cloning. Plants can be cloned using cuttings or tissue culture.
67
plant cuttings
a branch is cut off from the parent plant plant hormones are used to encourage roots to grow on the cutting the cutting is planted and grows into the new plant
68
methods of cloning
cloning animals: adult cell cloning embryo transplants cloning plants: tissue culture cuttings
69
Planting cuttings produces clones of the parent plant. The advantages of this technique are that a large number of plants with favourable characteristics can be produced ________ and cheaply.
Planting cuttings produces clones of the parent plant. The advantages of this technique are that a large number of plants with favourable characteristics can be produced quickly and cheaply.
70
Tissue culture
Tissue culture Small groups of cells are extracted (taken) from a plant and placed in a growth medium (such as a petri dish with plant food in). Division of these cells will eventually result in the formation of a clone of the parent plant. The advantages of this technique are that it is quick, space-efficient and time-independent. This technique is important for commercial use in nurseries and the preservation of rare species.
71
A farmer fertilised egg cells with sperm from his best bull before splitting the embryo. We call this process:
embryo transplantation
72
Adult Cell Cloning
Adult Cell Cloning Take an UNFERTILISED egg cell and REMOVE the NUCLEUS. The empty egg cell is then INJECTED with the nucleus from an ADULT BODY CELL belonging to the organism which is to be cloned. An ELECTRIC SHOCK is applied to the egg cell in order to STIMULATE CELL DIVISION. Once the embryo has grown into a LARGE BALL OF CELLS, it is IMPLANTED into a SURROGATE mother. The embryo (a clone of the original adult body cell) will continue to DEVELOP in the womb of the surrogate.
73
How was Dolly the sheep cloned?
ADULT CELL CLONING
74
according to the principle of natural selection...
The characteristics that maximise survival chances are passed on those with the best characteristics are more likely to breed individuals display genetic variation
75
Reasons for the slow acceptance of the natural selection theory were:
Reasons for the slow acceptance of the natural selection theory were: Genes not yet discovered evidence regarded as inconclusive (proved nothing) Religion
76
Lamarckian Evolution
Earlier giraffes had shorter necks and so would have to stretch to reach their food. Continual stretching resulted in the elongation of giraffe necks within a lifetime. Lamarck believed that this newly-acquired characteristic would then be passed on to the next generation.
77
Many of the other theories that have been proposed revolve around the concept that changes in an organism over the duration of its life are _______. The most famous of these theories was _______ theory of inheritance of acquired characteristics.
Many of the other theories that have been proposed revolve around the concept that changes in an organism over the duration of its life are heritable. The most famous of these theories was Lamarck’s theory of inheritance of acquired characteristics.
78
Two populations of the same species that become ___________ isolated will begin to diverge, leading to two new _____.
Two populations of the same species that become geographically isolated will begin to diverge, leading to two new species.
79
It is a common misconception that Darwin was alone in pioneering the thinking behind natural selection. In fact, Alfred Russel ______ wrote to Darwin in 1858, expressing his similar thinking. This caused Darwin to accelerate the process of publishing his ____.
It is a common misconception that Darwin was alone in pioneering the thinking behind natural selection. In fact, Alfred Russel Wallace wrote to Darwin in 1858, expressing his similar thinking. This caused Darwin to accelerate the process of publishing his book.
80
Darwin was not the only scientist to think of natural selection. What did Darwin and Wallace have in common?
joint writings travelled to islands
81
Speciation
two populations of the same species become geographically isolated the populations exhibit (show) genetic variation natural selection happens differently in different populations because of the environments and selection pressures this eventually leads to genetic divergence until the populations cannot interbreed to produce fertile offspring at this point they have become two distinct species
82
Why is antibiotic-resistant bacteria evidence of evolution?
Why is antibiotic-resistant bacteria evidence of evolution? Bacteria reproduce rapidly. Mutations occur during reproduction. If a mutated bacterium is resistant to antibiotics, it will survive exposure to antibiotics and go on to reproduce. This bacterium will represent the original ancestor of a new resistant strain.
83
apart from genes what are the two main sources of evidence for evolution are:
The two main sources of evidence for evolution are: Fossils Antibiotic resistant bacteria
84
To reduce the risks of bacterial resistance, doctors should avoid prescribing antibiotics ___________, patients must finish a _______ of antibiotics, and the use of antibiotics in _________ should be restricted.
To reduce the risks of bacterial resistance, doctors should avoid prescribing antibiotics unnecessarily, patients must finish a course of antibiotics, and the use of antibiotics in agriculture should be restricted.
85
Why can't decomposers act on many glaciers?
extreme, low temperatures
86
Why is the fossil record incomplete?
Why is the fossil record incomplete? A lot of early life forms were soft-bodied. Therefore, they did not leave behind many noteworthy traces. Geological activity has also caused the destruction of many traces of ancient life. Because of this, scientists cannot be certain about the origins of life on Earth.
87
The discovery of _____ as the mechanism (way) of inheritance and variation (i.e. that characteristics are passed on to offspring in genes) provides further evidence for the theory of evolution.
The discovery of genes as the mechanism of inheritance and variation (i.e. that characteristics are passed on to offspring in genes) provides further evidence for the theory of evolution.
88
What do Gregor Mendel's "units" appear to be similar to?
chromosomes
89
Large volcanic eruptions can cause changes in the levels of:
Large volcanic eruptions can cause changes in the levels of: pH light CO2 levels
90
Factors causing extinctions Abiotic (physical) factors Biotic (organism) factors
Factors causing extinctions Abiotic (physical) factors: Volcanic eruptions Atmospheric changes Biotic (organism) factors: Disease
91
Gregor Mendel experimented with ____ plants
Gregor Mendel experimented with pea plants the discovery of chromosomes helped support his work the DNA structure was discovered in the 20th centuary he was an Austrian monk
92
Extinctions occur when there are no remaining _______ of a species.
Extinctions occur when there are no remaining individuals of a species.
93
Which monk enhanced our understanding of genetics using experiments on pea plant?
Which monk enhanced our understanding of genetics using experiments on pea plant? Gregor Mendel
94
examples of biotic factors affecting a species
examples of biotic factors affecting a species new predator disease
95
The three-domain system proposed by Carl _____ classifies organisms based on _______ analysis.
The three-domain system proposed by Carl Woese classifies organisms based on chemical analysis.
96
Linnaean Classification
kingdom Phylum class order family genus species
97
Linnaean Classification mnemonic
Keep Pond Clean Or Froggy Gets Sick
98
Carl Woese's three-domain system includes:
Carl Woese's three-domain system includes: Bacteria True bacteria. Archaea Primitive bacteria, many of which are extremophiles (i.e. live in extreme environments such as hot thermal springs). Eukaryota Organisms that have complex subcellular structures (e.g. protists, fungi, plants and animals).
99
Give the common species name for the following latin names: Tiger human lion
Give the common species name for the following latin names: Tiger Panthera tigris Human Homo sapiens Lion Panthera leo
100
To which domain do protists, fungi, plants and animals belong?
eukarayota
101
what is true about evolutionary trees?
what is true about evolutionary trees? the start of the tree is a common ancestor used to show how scientists believe organisms are closely related the branches show the species that have evolved

sarah's biology class (7 decks)

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