Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Inheritance, Variation And Evolution > Flashcards

Inheritance, Variation And Evolution Flashcards

1
Q

Sexual reproduction

A

Involves the fusion of male and female gametes

Mixing of genetic information which leads to variety in the offspring

Sperm and egg cells in animals

Pollen and egg cells in flowering plants

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

Advantages of sexual reproduction

A

Produces variation in the offspring

If the environment changes variation gives a survival advantage by natural selection

Natural selection can be sped up by humans in selective breeding to increase food production

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

Asexual reproduction

A

Involves only one parent and no fusion of gametes

No mixing of genetic information leading to genetically identical offspring (clones)

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

Advantages of asexual reproduction

A

Only one parent needed

Faster than sexual reproduction as do not need to find a mate

Many identical offspring can be produced when conditions are favourable

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

Reproduction in parasites

A

Malarial parasites reproduce asexually in the human host, but sexually in the mosquito

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

Reproduction in fungi

A

Many fungi reproduce asexually by spores but also reproduce sexually to give variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Reproduction in plants

A

Many plants produce seeds sexually, but also reproduce asexually by runners such as strawberry plants, or bulb division such as daffodils

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

DNA

A

DNA is a polymer made up of two strands forming a double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Chromosome

A

The structure made up of DNA that codes for all the characteristics of an organism

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

Male chromosome

A

XY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Female chromosome

A

XX

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

Gene

A

A small section of DNA

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

Genome

A

The entire genetic material of an organism made up of genes

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

Polymer

A

A long molecule made up of repeating units

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

DNA bases

A

Adenine (A) - - - - Thymine (T)

Cytosine (C) - - - - Guanine (G)

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

Triplet code

A

A group of three bases coding for a specific amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Process of protein synthesis

A

The DNA is unzipped and a mRNA (an exact copy of the DNA) binds to each codon (three bases)

This is known as transcription

The mRNA chain moves out of the nucleus into the cytoplasm where it finds a ribosome

tRNA binds to the mRNA and also to amino acids floating in the cytoplasm

Once tRNA joins each mRNA the amino acids join together through bonds created by enzymes

This creates a chain of amino acids known as polypeptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mutation

A

A change in the base sequence

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

Three types of mutation

A

Substitution

Addition

Subtraction

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

Effects of mutations

A

No effect

Alter the proteins appearance

They may change the amino acids coded for and may change the shape of the protein – this could result in it being no longer able to function

They may be advantageous e.g. result in a more efficient enzyme

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

Allele

A

Different forms of the same gene

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

Homozygous dominant

A

Both allele’s are dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Homozygous recessive

A

Both allele’s are recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Heterozygous

A

Two different allele’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Genotype
The genetic make-up of an organism
26
Phenotype
An individuals observable traits
27
Polydactyl
Inherited condition in which a person has extra fingers or toes It is caused by a dominant allele
28
Huntington’s disease
Inherited disorder that affects the nervous system It is caused by a dominant allele
29
Cystic fibrosis
Inherited condition that causes sticky mucus to build up in your lungs and digestive system It is caused by a recessive allele
30
Amniocentesis
A test to see whether your child could grow up with genetic disorders Carried out 15-16 weeks before pregnancy A needle is inserted through the skin
31
Chronic villus sampling
A test to see whether your child could grow up with genetic disorders Carried out 10-12 weeks before pregnancy A catheter (long tube) is inserted through the the cervix
32
Genetic variation
Differences between individuals that are inherited from parents
33
Natural selection
When the best adapted organisms are able to survive ‘Survival of the fittest’
34
Selective breeding
Involves people taking charge of selection to produce new varieties of species
35
Process of selective breeding
Decide which characteristics are most important Choose parents that show these characteristics Breed them together Choose the best offspring from parents to breed the next generation Repeat the process
36
Advantages of selective breeding
Can choose - Disease resistance in food crops Animals which produce more meat or milk Domestic dogs with a gentle nature Large or unusual flowers
37
Genetic engineering
Add, change or remove an organisms gene to alter it’s characteristics
38
Process of making insulin (genetic engineering)
A cell which can produce insulin is taken from a healthy human The insulin gene is cut out of the human DNA using an enzyme A plasmid is used to transfer the gene The plasmid is removed from the bacteria and is cut open using an enzyme The insulin gene is inserted into the plasmid using another enzyme The plasmid with the insulin gene is taken up by bacteria so it can reproduce quickly The insulin is then collected and ready for use
39
Genetic engineering process
Selection of the desired characteristic The gene responsible for the characteristic is 'cut out' of the chromosome The gene is transferred and inserted into another organism replication of the modified organism
40
Cloning
When an organism has been produced by asexual reproduction and is genetically identical to its parents
41
Cloning in plants
Tissue sample scraped from parent cell Placed in agar jelly Grows in a petri dish Placed in a compost to finish growing OR The tip of a plant is cut You place it in a compost to let it grow
42
Adult cell cloning
A cell was taken from the udder of a sheep An egg was taken from the ovary of a sheep The nucleus was sucked out of the egg (enucleated) The udder cell and the enucleated are fused together with electricity Cell division occurs until an embryo is formed The embryo is implanted into the female sheep A calf is now born from the DNA of the male sheep
43
Evolution
The gradual change of a species characteristics
44
Charles Darwin’s theory of evolution
All species of living things have evolved from simple life forms that first developed
45
Why was Charles Darwin’s theory initially rejected?
Not enough fossil evidence Inheritance and genes where not known at the time
46
Jean-Baptiste Lamarck theory of evolution
He proposed that the way an organism behaved affected their features – if they used something a lot over time, this feature would grow and develop
47
Speciation
The formation of new species
48
The process of speciation
A population becomes geographically isolated from the original population (rivers) They are now different environmental conditions in the new population Mutations can occur causing variation Natural selection occurs, whereby the best adapted individuals survive and reproduce The new population eventually changes to the point where it can no longer inbreed with the old population
49
Gregor Mendel’s discovery
He found that some traits could be hidden within a generation, leading to the discovery of dominant and recessive alleles He used different coloured pea plants to do this
50
Fossil
The remains of an organisms that lived in the past found preserved in rock
51
Formation of fossils (frozen)
The organisms body is frozen to preserve its body
52
Formation of fossils (footprint)
A footprint fossil show the characteristics of the animal
53
Formation of fossils (skeletal)
The organism dies and gets covered by mud The organs of the organism decay The skeletal system of the organism is left The mud surrounding the organism becomes a rock The rock mineralises
54
Conditions for decaying
No oxygen Heat
55
Why don’t we have a complete fossil record?
Early organisms had soft bodies (no skeletal system) Fossils may have been destroyed Fossils have not been found
56
Reasons for extinction
The animals could not adapt to their new surroundings or environment
57
MRSA bacteria
Resistant to most antibiotics and dangerous once entering the body
58
How to prevent MRSA
Wash hands Only prescribe antibiotics when needed Patients finish full course
59
Classification
Is the organisation of living things into groups, according to their similarities
60
Domains
Kingdom Phylum Class Order Family Genus Species
61
Archaea
Primitive bacteria usually living in extreme environments
62
Bacteria
True bacteria
63
Eukaryota
Includes protists, fungi, plants and animals

Biology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions