V L2: Introduction to the DNA molecule Flashcards Preview

1st Year sem 2: Forensic Identification > V L2: Introduction to the DNA molecule > Flashcards

Flashcards in V L2: Introduction to the DNA molecule Deck (36)
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1
Q

what are the two types of nucleic acids?

A

DNA

RNA

2
Q

what is a nucleolus ?

A

Ribosome-producing factory

3
Q

what’s a eukaryotic cell?

A

Eukaryote, any cell or organism that possesses a clearly defined nucleus.

4
Q

repeating pentose-phosphate units….

A

5’ (arrow) 3’

5
Q

who stated the Double helical structure ?

A

Watson and Crick 1953

6
Q

DNA strands are….

A

Anti-parallel strands

7
Q

what are the 5 bases?

A
adenine 
thymine
guanine
cytosine 
uracil
8
Q

what happens if you heat DNA?

A

Heating de-stabilises the H-bonds (denaturing)

9
Q

whats temperature required to denature DNA known as?

A

Tm - melting temperature

10
Q

whats melting temperature of DNA dependent on?

A

GC% of the sequence

11
Q

what can you do if you have the DNA sequence of one strand?

A

complementary sequence can be determined

12
Q

what is a autosome and how many do we have?

A

any chromosome that is not a sex chromosome, 22 pairs.

13
Q

How many pairs fo sex chromosomes do we have?

A

1

14
Q

males are?

A

heterogametic

15
Q

what is Multiple mitochondrial genomes (mtDNA) ?

A

these DO NOT follow Mendelian genetic rules

16
Q

what are cells with a full set of chromosomes known as?

A

diploid cells

17
Q

what are cells with a half set of chromosomes known as?

A

haploid cells

18
Q

which sex chromosome is larger?

A

X is larger then Y

19
Q

How do X and Y chromosomes pair?

A

at meiosis via psuedoautosomal regions (PAR) at tips of the arms

20
Q

what are a Complex of proteins and DNA that are stacked together known as?

A

chromatin

21
Q

what size is chromatin?

A

30 nm fibre condensed form

22
Q

when nuclear DNA is damaged, mitochondrial DNA is often?

A

preserved

23
Q

mitochondrial DNA is what type of iheritence?

A

maternal

24
Q

what are the 4 molecular processes ?

A
  1. Transcription
  2. RNA processing
  3. Translation
  4. Replication
25
Q

what is the cell cycle?

A
mitosis 
cytokinesis 
G1 phase
S phase ( DNA replication)
G2 phase
26
Q

what are the steps of mitosis?

A

prophase
metaphase
anaphase
telophase

27
Q

what happens in prophase?

A

Chromatin begins to condense and is visible in the form of chromosomes. Spindle fibres begin to form as well as centrioles.

28
Q

what happens in metaphase?

A

Chromosomes line up on mitotic spindle. Chromosomes are attached to spindle forms on opposite sides

29
Q

what happens in anaphase?

A

sister chromatids separate from each other and are pulled towards opposite ends of the cell.

30
Q

what happens in telophase?

A

mitotic spindle is broken down
Two new nuclei form, one for each set of chromosomes. Nuclear membranes and nucleoli reappear.
The chromosomes begin to decondense

31
Q

what are the two steps of protein synthesis?

A
  1. transcription (DNA copied to RNA)

2. followed by translation (RNA template for the synthesis of a protein)

32
Q

what is meiosis ?

A

A specialised nuclear division producing haploid cells, reducing the chromosome number by half

33
Q

The information contained in the ____ in the ___ is transcribed into _____ and the _____ contained in the mRNA are translated into an _____ ____ _____.

A
  1. genes
  2. DNA
  3. mRNA
  4. codons
  5. amino acid sequence
34
Q

what can a change in gene do?

A

change ether function of a protein

35
Q

why are proteins useful in forensics?

A

Proteins can be studied to identify differences in individuals

36
Q

why is RNA useful forensics?

A

Cells from different biological sources can be identified using RNA