Topic 3.2: Chromosomes Flashcards Preview

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Flashcards in Topic 3.2: Chromosomes Deck (25)
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1
Q

Prokaryotes chromosomes

A

a) Have a single circular molecule made of naked DNA (Genophore)
b) May have additional plasmids

2
Q

Eukaryotes chromosomes

A

a) Multiple linear DNA molecules packaged with histones

b) Do not have plasmids

3
Q

Plasmids

A

Small, autonomous circular DNA molecules

4
Q

Centromere

A

Constriction point of a chromosome

a) p-arm (short)
b) q-arm (long)

5
Q

Identifying the region in which a gene is positioned

A

a) Chromosome
b) Arm
c) G band location

6
Q

Homologous Chromosomes

A

Paired chromosomes inherited from both parents in sexually reproducing animals

7
Q

Characteristics of Homologous Chromosomes

A

a) Structural features

b) Genes at the same loci positions

8
Q

Diploid

A

a) Two sets of chromosomes

b) Somatic cells in the organism

9
Q

Haploid

A

a) One set of chromosomes

b) Sex cells / Gametes

10
Q

Number of chromosomes in humans

A

23 pairs of chromosomes

11
Q

Homologous Autosomes

A

a) 22 pairs

b) Do not determine sex

12
Q

Sex chromosomes

A

a) 23rd pair

b) XX / XY

13
Q

Y Chromosome

A

Contains the genes for developing male sex characteristics (SRY gene)

14
Q

Karyotype

A

Identify the number and types of chromosomes in a eukaryotic cell

15
Q

Functions of karyotyping

A

a) Identify the sex of offspring

b) Diagnose potential chromosome abnormalities

16
Q

Processo of karyotyping

A

a) Harvesting cells
b) Chemically inducing cell division, arresting mitosis while the chromosomes are condensed
c) Determine whether chromosomes appear with sister chromatids or not

17
Q

Karyogram

A

Visual profile that shows the chromosomes of a

cell in homologous pairs of decreasing length

18
Q

Autoradiography (John Cairns)

A

Technique for measuring the length of DNA molecules while uncoiled

19
Q

Process of Autoradiography

A

a) Radioactive thymidine is incorporated into a cell’s DNA
b) Chromosomes were fixed to a photographic surface and treated with silver bromide (AgBr)
c) Radiation converts silver ions into insoluble grains that is visible via electron microscopy when a film is developed

20
Q

Chromosome number and species

A

Chromosome number is a characteristic feature of members of a particular species

21
Q

What happens if two organisms with different diploid numbers interbreed?

A

a) Unlikely to interbreed

b) Offsprings are infertile (Donkey 62 + Horse 64 = Mule 63)

22
Q

Chromosome number of:

a) Parascaris equorum
b) Oryza sativa
c) Homo sapiens
d) Pan troglodytes
e) Canis familiaris

A

a) 4
b) 24
c) 46
d) 48
e) 78

23
Q

Genome size of:

a) T2 phage 170,000 bp
b) E. Coli. 4.6 million bp
c) Drosophila melanogaster 130 million bp
d) Homo Sapiens 3.2 billion bp
e) Paris Japonica 150 billion bp

A

a) Viruses and bacteria tend to have very small genomes
b) Prokaryotes have smaller genomes than eukaryotes
c) Sizes of plant genomes can vary dramatically

24
Q

Chromosome number, genome size and genetic complexity

A

Chromosome number and genome size do not provide a valid indication of genetic complexity

25
Q

Number of genes and biological complexity

A

The number of genes present in an organism will differ between species and is not a valid indicator of biological complexity

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