Brainscape's Knowledge GenomeTM

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


See full index

Biology > Inheritance, Variation and Evolution > Flashcards

Inheritance, Variation and Evolution Flashcards

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

What is deoxyribonucleic acid (DNA)?

A

The chemical a cell’s nuclear genetic material is made from

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

What are chromosomes?

A

Long molecules of DNA that normally come in pairs
Humans have 23 pairs.
The 23rd pair carries the genes which decide a person’s sex (XX or XY)

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

What is a gene?

A

A small section of DNA found on a chromosome.
Each gene codes for a particular sequence of amino acids, which are put together to make a specific protein

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

How many different amino acids are there and how many possible proteins?

A

20 amino acids
1000s of proteins

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

What is a genome?

A

An organism’s entire set of genetic material

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

What 2 things can we do now that we have worked out the entire human genome?

A

1: genes linked to diseases can be identified - this helps us better understand inherited diseases, so we can develop effective treatments
2: tiny differences in people’s genomes can be studied - this helps us trace migration patterns of past human populations

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

What 2 things make up a nucleotide?

A

A sugar-phosphate backbone and one of the 4 bases

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

What are the two complementary base pairs?

A

A + T
G + C

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

How many bases code for 1 amino acid?

A

3

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

Talk me through protein synthesis.

A

1: mRNA is copied from DNA template and moves to the ribosomes
2: proteins are synthesised on ribosomes
3: carrier molecule brings specific amino acid
4: they form a chain

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

What are mutations?

A

Changes to the sequence of DNA bases. They occur continuously

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

What effect do most mutations have?

A

No effect on the protein

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

What effect do some mutations have?

A

Alter the protein slightly but its shape and function are not affected

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

What effect do very few mutations have?

A

Change the shape of the protein and affect its function.
Eg, an enzyme substrate no longer fits or a structural protein loses its strength

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

Tell me about asexual reproduction.

A

One parent
Cell division by mitosis
Produces genetically identical offspring
Advantages:
Fast compared to sexual reproduction, so many identical offspring can be produced in favourable conditions

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

Tell me about sexual reproduction.

A

Two parents
Cells divide by meiosis and mitosis
Produces offspring containing a mixture of the parent’s genes
Advantages:
The variation produced in the offspring increases the chance that some individuals of a species will survive a change in the environment.
We can use selective breeding to utilise the variation in offspring and increase food production

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

Describe meiosis to me.

A

1: The cell duplicates its genetic information
2: The cell divided and each new cell had one copy of each chromosome
3: Both cells divide again to make 4 gametes
4: Each gamete only has a single set of chromosomes

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

What is an allele?

A

A version of a gene

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

What do we mean by dominant?

A

An allele that is always expressed

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

What do we mean by recessive?

A

An allele that is only expressed when 2 copies are present

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

What does homozygous mean?

A

Both of an organisms alleles for a trait are the same

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

What does heterozygous mean?

A

An organisms alleles for a trait are different

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

What is a genotype?

A

An organisms combination of alleles

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

What is a phenotype?

A

The characteristics an organism has (visible)

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

What are the two types of genetic diagrams?

A

Genetic cross and Punnett square

26
Q

What are inherited disorders?

A

Disorders caused by certain alleles that are inherited from the parents

27
Q

What is polydactyly?

A

A genetic disorder where a baby’s born with extra fingers or toes. It’s caused by a dominant allele.

28
Q

What is cystic fibrosis?

A

A genetic disorder of the cell membranes. It’s caused by a recessive allele.

29
Q

What is the chance of a baby having an inherited disorder if it is a dominant allele?

A

50/50

30
Q

What is the chance of a baby having an inherited disorder if it is a dominant allele?

A

25% that they have it, 50% that it is present but not phenotype (carrier), 25% that they are unaffected

31
Q

What are 3 reasons against embryonic screening?

A

1: Screening is expensive
2: People might want to screen their embryos so they can pick the most ‘desirable’ one
3: It implies that people with genetic problems are ‘undesirable’

32
Q

What are 3 reasons for embryonic screening?

A

1: It will help to stop people suffering
2: Treating disorders costs the government a lot of money
3: There are laws to stop it going too far

33
Q

What were Mendel’s 3 conclusions?

A

1: Hereditary ‘units’ determine characteristics
2: The units are passed on to offspring unchanged
3: The units can be dominant or recessive

34
Q

What happened in the years between 1850 and 1900?

A

Mendel conducted breeding experiments with plants
Mendel published his research
Scientists became familiar with chromosomes. They were able to observe how they behaved during cell division

35
Q

What happened between 1900 and 1950 or so?

A

Scientists realised there were similarities in the ways Mendel’s ‘units’ and chromosomes acted. It was proposed that the ‘units’ (genes) were found on the chromosomes
Structure of DNA determined
Scientists went on to find out exactly how genes work

36
Q

What is variation?

A

Differences in the characteristics of organisms

37
Q

What is an example of environmental variation?

A

Differences in the conditions in which an organism develops cause variation, eg, leaf colour

38
Q

What is an example of genetic and environmental variation?

A

For most characteristics, variation is caused by both genetics and the environment, eg, plant height

39
Q

Talk to me about Charles Darwin.

A

Best known for the theory of evolution by natural selection
He published ‘On the origin of species’ (1859)
The theory challenges some religious ideas (Adam and Eve)
He researched by a world expedition, experiments, discussions, knowledge of geology and fossils
He had setbacks of insufficient evidence to convince many scientists because the mechanism wasn’t known about.

40
Q

Talk to me about Alfred Russel Wallace.

A

Best known for work on warning colouration of animals and his theory of speciation
He published joint writings with Darwin on evolution (1858)
He researched by observations from world travels provided evidence for the theory of evolution by natural selection.

41
Q

What is the theory of evolution by natural selection?

A

All of today’s species have evolved form simple life forms that first started to develop over three billion years ago.
Jean-Baptiste Lamarck argued that changes acquired during an organism’s lifetime were passed on to its offspring, but experiments didn’t support this hypothesis.

42
Q

Describe the flow chart of evolution.

A

Species show wide variation + Limited resources mean organisms are in competition > organisms with the most suitable characteristics for the environment are more likely to survive > these organisms are more likely to breed > the beneficial characteristics are passed on and gradually become more common in the population.

43
Q

What is speciation?

A

The development of a new species by natural selection
Two populations of a species > populations are isolated > populations adapt to new environments > development of new species.
Two groups become separate species when individuals have changed so much that they won’t be able to breed with one another to produce fertile offspring

44
Q

What is selective breeding?

A

Breeding plants or animals for particular characteristics

45
Q

What are 4 uses of selective breeding?

A

1: greater meat or milk production
2: big or unusual flowers
3: a good, gentle temperament in dogs
4: disease resistance in crops

46
Q

What are the 4 types of cloning?

A

1: Embryo transplants
2: Tissue culture (plants)
3: Cuttings (plants)
4: Adult cell cloning

47
Q

Describe adult cell cloning.

A

Adult body cell gets the nucleus removed.
Egg cell also gets a nucleus removed.
The nucleus of the body cell is combined with the everything else of the egg cell.
Electric shock makes the cell divide.
The embryo is implanted into the surrogate mother.
Live animals (with same genes as adult body cell) is created.

48
Q

What is genetic engineering?

A

The transfer of a gene responsible for a desirable characteristic from one organism’s genome into another organism.

49
Q

What are 3 uses of genetic engineering?

A

1: genes for producing human insulin transferred to bacteria
2: genes for bigger and better quality fruit transferred to crops
3: genes for resistance to insects, diseases, herbicides transferred to crops.

50
Q

Describe how to conduct genetic engineering.

A

Get a genome with desired characteristic and cut the gene out using ligase enzymes.
Gene is inserted into vector (bacteria plasmid for example)
Vector (plasmid) is introduced to the target organism

51
Q

What are the pros of GM crops?

A

Greater yields
Helps people with diets that lack nutrients
Already being grown without problems

52
Q

What are the cons of GM crops?

A

Could reduce biodiversity
Concerns about effects on human health
Transplanted genes may spread into the wild

53
Q

What are fossils?

A

Remains of organisms from many thousands of years ago.

54
Q

What are the 3 ways that fossils are formed?

A

1: gradual replacement by minerals - happens to slow decaying parts
2: casts and impressions - eg, footprints burrows and rootlet traces
3: preservation - in places where conditions prevent decay, parts of organisms can be preserved - eg, amber, glaciers and peat bogs

55
Q

What are 3 ways to reduce the rate of development of antibiotic-resistant strains?

A

1: not prescribing antibiotics for non-serious or viral infections
2: reducing the use of antibiotics in agriculture
3: patients taking the full course of antibiotics to kill all the bacteria

56
Q

What is the Linnaean system?

A

It was developed by Carl Linnaeus
It organises organisms by their characteristics into groups

57
Q

What is the order of the Linnaean system?

A

Kingdom > Phylum > Class > Order > Family > Genus > Species

58
Q

What are evolutionary trees?

A

They show how scientists think different species are related to each other

59
Q

What is extinction?

A

When no individuals of a species remain

60
Q

What are 5 reasons for extinction?

A

1: environmental change
2: new predators
3: new diseases
4: competition
5: catastrophic events

Biology (8 decks)

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