C12 Nucleic acid

Question 1

Why do we need proteins in the body

Answer 1

Important macromolecules
- regualtion
- transport
- protection
- contraction
- structure
- energy

Question 2

What is nucleic acid

Answer 2

Organic macromolecules (C,H,O,N,P), main information-carrying molecules
Polynucleotides - a chain of repeating monomers called nucleotides

Question 3

Nucleotide

Answer 3

pentose sugar + nitrogenous base

Question 4

Nucleoside

Answer 4

nucleoside + phosphate group

Question 5

Similarities & differences between DNA & RNA- No. of strands & shape of molecule

Answer 5

DNA- double helix
RNA- single

Question 6

Similarities & differences between DNA & RNA- type of sugar

Answer 6

DNA- Deoxyribose
RNA- Ribose

Question 7

Similarities & differences between DNA & RNA- names of bases

Answer 7

DNA- Adenine, thymine, guanine, cytosine
RNA- Adenine, uracil, guanine, cytosine

Question 8

Similarities & differences between DNA & RNA- relative length of molecule

Answer 8

DNA- longer
RNA- shorter

Question 9

What is a gene

Answer 9

segment of DNA that codes for a protein

Question 10

What is an allele

Answer 10

Alternative form of a gene

Question 11

What is the connection between DNA, RNA & protein synthesis

Answer 11

Transcription- DNA -> mRNA
Translation- mRNA -> protein

Question 12

Describe transcription

Answer 12

1. Initiated by transcription factors that recruit RNA polymerase
2. 2 strands of DNA separate
3. RNA polymerase binds to promoter region
4. Genetic information is copired from the template strand of NDA to make a strand of mRNA
5. RNA polymerase catalyses the formation of a mRNA chain following the rules of complementary base pairing
6. Transcription ends at a terminator sequence
7. mRNA exits nucleus through nuclear pores into the cytoplasm

Question 13

Coding strand

Answer 13

contains gene sequence

Question 14

Template strand

Answer 14

used to make mRNA

Question 15

Describe translation

Answer 15

1. mRNA carries genetic information from the nucleus to the ribosomes
2. Sequence is read by ribosome from codon
3. Translation starts at the start codon (AUG) of each gene in the mRNA
4. Each codon codes for a specific amino acid
5. tRNA with a complimentary sequence (anticodon) binds to each codon
6. the tRNA also carries the amino acid specified by the codon
7. amino acids are joined together by peptide bonds. the sequence specified by the mRNA, to make peptide/protein

Question 16

Genotype

Answer 16

the actual gene

Question 17

Phenotype

Answer 17

A person’s appearance

Question 18

Chromatin

Answer 18

DNA complexed with proteins (histones)

Question 19

Chromosome

Answer 19

chromatin condenses -> chromatid -> pair of chromatids= chromosome

Question 20

Mitosis- Interphase

Answer 20

• Time between cell divisions
• DNA= thin threads of chromatin
• DNA replication occurs in S phase (organelles other than centrioles & nucleus duplicate)

Question 21

Mitosis- Prophase

Answer 21

• Chromatin condenses into chromosomes
• Centrioles move to opposite ends of the cell
• Nuclear envelope dissolves
• Microtubules form near centrioles

Question 22

Mitosis- Metaphase

Answer 22

• Chromosomes align in the center of the cell
• Spindle fiber attach to centromere of each chromosome

Question 23

Mitosis- Anaphase

Answer 23

• Spindle fibers contract, chromosomes split into chromatids
• chromatids move towards opposite ends of a cell
• cytokinesis begins, cleavage forms around the cell

Question 24

Mitosis- Telophase

Answer 24

• Chromosome unravels to become chromatids
• Nuclear envelope reforms

Question 25

Mitosis- Cytokinesis

Answer 25

- cell division to produce 2 identical daughter cells

Question 26

Meiosis- Prophase I

Answer 26

- Duplicated chromosomes become visible as chromatids - Homologous chromosomes synapse to form tetrads - Crossing over may occur

Question 27

Meiosis- Metaphase I

Answer 27

- Homologous chromosomes align at the center of the cell - Random assortment of homologous chromosomes

Question 28

Meiosis- Anaphase I

Answer 28

Homologous chromosomes move apart to opposite sides of the cell

Question 29

Meiosis- Telophase I

Answer 29

Nuclear envelope reforms

Question 30

Meiosis- Prophase II

Answer 30

Each chromosome consists of 2 chromatids

Question 31

Meiosis- Metaphase II

Answer 31

- chromosome aligns along center of cell

Question 32

Meiosis- Anaphase II

Answer 32

Chromatids separate & each is now a chromosome

Question 33

Meiosis- Telophase II

Answer 33

- Nuclear envelope reforms - Cells divide to form 4 daughter cells with haploid number of chromosomes

Question 34

What cell type undergoes mitosis

Answer 34

somatic cells: a biological cell forming the body of a multicellular organism

Question 35

What cell type undergoes meiosis

Answer 35

Germ cell: cells that give rise to gametes (located in gonads)