Brainscape's Knowledge GenomeTM

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


See full index

Biology Higher GCSE Edexcel > Chapter Three: > Flashcards

Chapter Three: Flashcards

You may prefer our related Brainscape-certified flashcards:
GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route A flashcards AP® Biology flashcards GCSE Geography - AQA flashcards Biology 101 flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What are the three advantages of Asexual Reproduction?

A

+Rapid Populating
+No mates required
+Emergency option

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

What are the three disadvantages of Asexual Reproduction?

A
  • No diversity
  • Prone to extinction
  • Cannot adapt
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is rapid populating an advantage of asexual reproduction?

A

Asexual reproduction gives the ability to produce large quantities of offspring

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

Why is not having a mate an advantage of asexual reproduction?

A

Finding a mate can be difficult for organisms in desolate environments

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

Why is asexual reproduction a good emergency option?

A

In dire situations, plants and organisms can keep themselves alive and produce others to help them.

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

Why does asexual reproduction produce offspring with no diversity?

A

Traits are only passed on from one parent, so there is no genetic mixing meaning all offspring produced are identical.

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

Why are offspring of asexual reproduction prone to extinction?

A

Same traits mean same weaknesses. Predators that have evolved to kill a single organism can wipe out an entire population.

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

Why can the offspring of asexual reproduction not adapt?

A

An organism has established reactions to certain things which are passed down in asexual reproduction, making it almost impossible for them to adapt to any environment changes.

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

What is the purpose of sexual reproduction?

A

To produce offspring that resemble the parents, but are not identical.

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

What are the sex cells called in organisms?

A

Gametes

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

Name the advantages of sexual reproduction:(2)

A

More variation - more chance of survival

Bad genes can become extinct through meiosis and natural selection

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

Name the disadvantages of sexual reproduction:(4)

A

Requires two parents
Takes time and energy
Favorable genes can also become extinct through meiosis
Produces less offspring than asexual reproduction

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

What is Meiosis?

A

A type of cell division that produces gametes

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

How many chromosomes does a human body cell contain?

A

46 (23 pairs)

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

How many chromosomes does a gamete contain?

A

23

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

How does Meiosis differ to Mitosis?

A

They produce four daughter cells

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

What does Meiosis produce?

A

Four genetically haploid daughter cells

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

What is the Genome?

A

The haploid set of chromosomes

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

What is formed at fertilization?

A

A Zygote

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

What does a zygote contain?

A

23 pairs of chromosomes - 23 single chromosomes from each parent

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

What do chromosomes contain?

A

Genes

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

What are Genes?

A

A distinct sequence of nucleotides forming part of a chromosome

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

What does DNA stand for?

A

Deoxyribose Nucleic Acid

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

What is DNA?

A

The complex chemical that carries genetic information

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

What are chromosomes?

A

A thread-like structure of nucleic acids and proteins. Carries genetic information in the form of genes.

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

What are the function of the bases in DNA?

A

To carry different codes needed for different amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the code for an amino acid made of?

A

Three bases in a particular order

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

What are the four different bases of DNA?

A

Thymine, T
Adenine, A
Guanine, G
Cytosine, C

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

What does Thymine pair with?

A

Adenine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does Guanine pair with?

A

Cytosine

31
Q

What bonds hold the bases of DNA together?

A

Hydrogen Bonds

32
Q

What bases form three hydrogen bonds?

A

Guanine and Cytosine

33
Q

What bases form two hydrogen bonds?

A

Adenine and Thymine

34
Q

What are Proteins made up of?

A

Large numbers of amino acid molecules

35
Q

What is a Mutation?

A

A change that occurs in a gene

36
Q

What causes a Mutation?

A

They can be random or caused by radiation or chemicals.`

37
Q

What do Mutations cause? (Terms of genetic code)

A

Alteration to the base pair sequence

38
Q

What’s the difference between DNA mutations in normal body cells and sex cells?

A

If changes occur in normal body cells, the changes are lost when we die. If changes occur in sex cells, there is a possibility they will be passed on to the next generation.

39
Q

How is a new species produced?

A

Through the combined effect of mutations, environmental changes and natural selection

40
Q

What is transcription?

A

The copying of DNA in the process of creating a protein.

41
Q

Where does transcription occur?

A

In the cell nucleus

42
Q

What is the first stage of Transcription?

A

The DNA in a gene unzips so both strands are separate

43
Q

What is the second stage of Transcription?

A

Complementary bases attach to the strand being copied.

44
Q

What is the third stage of Transcription?

A

Thymine is not present so a different base (U) joins with Adenine

45
Q

What is the fourth stage of Transcription?

A

Messenger RNA is formed

46
Q

What is the difference between DNA and mRNA? (In terms of exiting/entering the nucleus)

A

mRNA is small enough to leave the nucleus and travel to the ribosomes in the cytoplasm.

47
Q

What is translation?

A

The process of mRNA being interpreted and new proteins forming

48
Q

Where does translation take place?

A

In the Ribosomes

49
Q

What is the first step of Translation?

A

The mRNA attaches to a ribosome which ‘reads’ the mRNA

50
Q

What is the second step of Translation?

A

The ribosome decodes the mRNA in groups of three (base triplets or codons) which are complementary in transfer RNA

51
Q

What is the third step of Translation?

A

The tRNA collects its specific amino acids and returns to the mRNA

52
Q

What is the fourth step of Translation?

A

The amino acids are lined up in order of the instructions of the mRNA

53
Q

What is the fifth step of Translation?

A

Bonds form between the amino acids and a polypeptide chain is formed

54
Q

What is the sixth step of Translation?

A

The polypeptide chain folds and becomes a specific shape forming a protein

55
Q

What is an allele?

A

each of two or more alternative forms of a gene that arise by mutation

56
Q

What does dominant mean in the terms of genetics?

A

an allele or a gene that is expressed in an organism’s phenotype, masking the effect of the recessive allele or gene when present

57
Q

What does recessive mean in the terms of genetics?

A

an allele or gene in which the effect is masked by the effects of a dominant gene or allele

58
Q

What does Homozygous mean?

A

When an individual has two of the same allele

59
Q

What does Heterozygous mean?

A

When an individual has two alleles that are different

60
Q

What is a genotype?

A

the genetic constitution of an individual organism

61
Q

What is a phenotype?

A

A set of observable characteristics of an individual

62
Q

What is cystic fibrosis caused by? (In the terms of alleles)

A

Recessive Allele

63
Q

What does Cystic Fibrosis cause?

A

The individual to produce abnormally thick and sticky mucus in their lungs and airways

64
Q

If a person has one copy of the allele causing CF but one not carrying CF, what are they referred to as?

A

A carrier

65
Q

What is an example of multiple alleles for one gene?

A

The ABO blood group

66
Q

What is codominance?

A

When two or more alleles are expressed in the same phenotype

67
Q

Which is more domination? I^A or I^B?

A

Neither, none are dominant over each other

68
Q

True or False? Both I^A and I^B are dominant over I^O.

A

True

69
Q

If a person has the genotype I^A I^O, what phenotype are they?

A

A

70
Q

What sex chromosomes code for a male?

A

XY

71
Q

Why does the sperm determine the sex of the fetus?

A

The Sperm carries the alternating sex chromosome, the ovum always contains the X chromosome but the sperm can contain either the X or Y.

72
Q

What are the effects of Haemophilia?

A

People with it have a problem forming blood clots

73
Q

What causes Haemophilia?

A

A recessive gene on the X chromosome

74
Q

What environmental factors can affect our phenotype?(5)

A
  • climate
  • diet
  • physical accidents
  • culture
  • lifestyle

Biology Higher GCSE Edexcel (4 decks)

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