Brainscape's Knowledge GenomeTM

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


See full index

Biology > Unit 2: Section 2 - Genetics > Flashcards

Unit 2: Section 2 - Genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
0
Q

Which nitrogenous bases specific base pair to each other?

A

Adenine and Thymine (A-T)

Cytosine and Guanine (C-G)

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

What 3 main things is a nucleotide made up of?

A
  • phosphate group
  • deoxyribose sugar
  • nitrogenous base (varies, either A T C or G)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many hydrogen bonds between the base pairs?

A

2 A-T

3 C-G

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

Give 3 ways DNA is well adapted for it’s function

A
  • helical shape, makes it compact
  • strong covalently bonded sugar-phosphate backbone in a double helix to protect genetic material
  • genetic information (organic bases) have paired structure which makes it much easier to copy itself (self replication)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is DNA stored in eukaryotic cells?

A
  • DNA in double helix
  • wound around proteins called histones
  • histones also help to support DNA
  • DNA wound round histones is coiled up repeatedly
  • this forms a single chromosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is DNA stored in prokaryotic cells?

A
  • same DNA double helix
  • forms circular chromosome
  • this is then coiled
  • then supercoiled (like a snake to fit in cell)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many organic bases form an amino acid?

A

3

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

Which two areas of DNA in eukaryotic cells don’t code for amino acids?

A
  • DNA sections called introns

- DNA regions with multiple repeats outside of genes e.g. CCTTCCTTCCTT

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

How does DNA affect our nature, development and phenotype?

A
  • DNA codes for certain alleles which control charecteristics e.g. Eye colour
  • DNA determines amino acid sequence
  • determines proteins and enzymes formed
  • enzymes control metabolic pathways
  • metabolic pathways help determine nature, phenotype and development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can mutation cause none functional enzyme?

A
  • deletion, addition, repetition of organic base
  • change in amino acid sequence
  • produces new allele which codes for protein
  • enzyme is protein, if allele is different a different enzyme is produced
  • because of different amino acid sequence it may not fold up properly
  • different tertiary structure, active site different shape, not complementary to substrate
  • cannot form enzyme-substrate complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a haploid and diploid cell?

A

Diploid: number of chromosomes in normal body cells, have 2 of each chromosome (2n) one from mum, one from dad
Haploid: number of chromosomes in gamete, only one of each chromosome (only half from mum ovum or only half from dad sperm) (n)

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

What is an allele?

A

Different forms of the same gene

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

How many devisions in meiosis?

A

2

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

What is the centre of the double-armed chromosomes called?

A

Centromere

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

What is the single strand in a double-armed chromosome called?

A

Chromatid

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

What are the ‘poles’ in cell replication called?

A

Centrioles

16
Q

Why is it important for gametes to have half the number of chromosomes as normal body cells?

A
  • so when fertilisation takes place, the embryo formed has the correct diploid number of chromosomes
  • if they had the normal number, the diploid number, that would mean the embryo formed would have twice the number of chromosomes it needs
17
Q

Explain what crossing over is and how it leads to genetic variation

A
  • during meiosis 1 homologous pairs of chromosomes come together
  • the chromatids twist around each other and bits swap over (alleles)
  • chromatids now contain different combinations of alleles
  • this means each of the four daughter cells will contain chromatids with different combinationsof alleles
18
Q

Explain meiosis (6)

A
  • DNA unravels and replicates
  • DNA condenses to form double armed chromosomes
  • chromosomes arrange themselves into homologous pairs
  • these pairs seperate meiosis 1
  • the pairs of sister chromatids then seperate in meiosis 2
  • four HAPLOID genetically different cells are produced
  • in exam draw diagrams (especially if stated)
19
Q

Explain what independant segregation is

A
  • chromosome pairs can split up in any way

- so daughter cells produced can contain any combination of maternal and paternal chromosomes with different alleles

20
Q

What is the founder effect and how does it reduce genetic diversity?

A
  • few organisms from population start new colony
  • less alleles reduced gene pool
  • inbreeding, higher incidence of genetic disease
  • caused by migration, seperation, even religion
21
Q

What is selective breeding?

A
  • select few organisms with desired charecteristics to breed
  • they pass on genetic information with desired allele
  • offspring express desired characteristic
  • reduced gene pool

Biology (13 decks)

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