3B-inheritance

Question 1

where is DNA found?

Answer 1

in the chromosones in the nucleus

Question 2

what do genes do?

Answer 2

they determine features by instructing cells to produce particular proteins which then lead to the development of the feature. AKA the genes are a section of DNA that codes for a particular protein

Question 3

what is a molecule of DNA made up of?

Answer 3

made of two strands of molecules called nucleotides.
each nucleotide contains a sugar molecule (deoxyribose), a phosphate group, and a nitrogen-containing group called a base

Question 4

what does a nucleotide contain?

Answer 4

each nucleotide contains a sugar molecule (deoxyribose), a phosphate group, and a nitrogen-containing group called a base.
there are 4 types of bases:
adenine (A), thymine (T), cytosine (C), guanine (G)

Question 5

what are the 4 types of bases?

Answer 5

there are 4 types of bases:
adenine (A), thymine (T), cytosine (C), guanine (G)

Question 6

what is important to remember about the bases?

Answer 6

in the nucleotides, adenine is always opposite to thymine (on separate nucleotides) and cytosine is opposite to guanine. THEY ARE COMPLIMENTARY BASES meaning they always link with each other (this is the base-pairing rule). a consequence of this is that the amounts of A and T are equal as well as C and G

Question 7

what is the genome?

Answer 7

the entire DNA of an organisms

Question 8

what is a gene?

Answer 8

genes are a section of DNA that codes for a particular protein

Question 9

what does the phosphate group do?

Answer 9

hold together the nucleotides in each strand together

Question 10

what do the hydrogen bonds do?

Answer 10

hold the pairs of bases together

Question 11

what shape is DNA?

Answer 11

a molecule made up of two strands coiled together to form a double helix (linked together by a series of paired bases)

Question 12

can DNA replicate itself?

Answer 12

yes, it is the only chemical that can. because of this, it is able to pass genetic information form one generation to the next as ‘genetic code’

Question 13

what is DNA?

Answer 13

the molecule that stores genetic information in the form of a code. it is a polymer, a long-chain molecule. it is made up of repeating units called nucleotides

Question 14

what is a gene?

Answer 14

a short length of DNA that codes for a single protein

Question 15

what is a chromosome?

Answer 15

a single DNA molecule coded around proteins called histones, allow DNA to be packed and protected

Question 16

how do nucleotides code for proteins?

Answer 16

they determine the order of amino acids as the sequence of bases in DNA code code for the sequence of amino acids in proteins

Question 17

what are alleles?

Answer 17

all individuals of the same species have the same genes at the same locations on their chromosomes. However, there are many different forms of these genes. these are called alleles.

Question 18

what shape is RNA

Answer 18

single stranded, not a helix

Question 19

what are the bases in RNA

Answer 19

adenine, cytosine, guanine, URASIL

Question 20

what type of sugar is in DNA, RNA?

Answer 20

DNA-deoxyribose
RNA-ribose

Question 21

where is RNA found?

Answer 21

in the nucleus, cytoplasm

Question 22

in how many forms does DNA and RNA have?

Answer 22

DNA - 1 form
RNA - 3 forms

Question 23

what is transcription? describe it step by step

Answer 23

1. DNA strands are connected by hydrogen bonds. They are separated and so the bases are exposed of the TEMPLATE STRAND
2. RNA nucleotides roam freely in the nucleus. they form complementary pairs with the DNA when they are exposed (n.b., uracil binds to adenine)
3. the RNA nucleotides join together to form an mRNA chain
4. when this is completed, the mRNA detaches and leaves the nucleus through the nuclear pore
5. the 2 DNA strands re-join
6. RNA polymerase catalyses the reaction ( by seperating the DNA strands)
7. the mRNA goes to the ribosomes in the cytoplasm

Question 24

what is special about genetic code?

Answer 24

in DNA there are 4 different types of bases but there are 20 different amino acids. therefore, the mRNA chain can be subdivided into a series of triples, or CODONS.
each CODON codes for a specific amino acid

Question 25

what is universal code?

Answer 25

the same base code for the same thing in all organisms

Question 26

what is translation? describe the process step by step.

Answer 26

1. mRNA enters the ribosome
2. ribosomes translate the mRNA into an amino acid chain, or protein. this requires the mRNA chain, the ribosome, and tRNA molecules (the tRNA reads code (there’s 64 types of tRNAs)
3. each tRNA molecule has an amino acid attached to an anticodon, which is complementary to a specific mRNA codon
4. the mRNA attaches to the ribosome and, here, each mRNA codon is matched with a complementary anticodon on a tRNA molecule; this begins with the start codon
5. the ribosome then catalyses a reaction (the formation of a peptide bond) between the two amino acids attached to two adjacent tRNA molecules, gradually forming a chain of amino acids
6. this chain is then folded to form a functional protein
7. the process continues until a stop codon is reached

Question 27

what is DNA replication?

Answer 27

the polynucleotide strands of DNA separate
each strand then acts as a template for the new strand of DNA
the DNA polymerase then assembles nucleotides into two new strands according to the base-pairing rule
the two identical DNA molecules are formed- each contains a strand from the parent DNA and a new complementary strand

Question 28

what does RNA have instead of thymine?

Answer 28

uracil

Question 29

what are the stages of protein synthesis?

Answer 29

transcription, translation including mRNA, ribosomes, tRNA, codons, anti codons

Question 30

what does mRNA do?

Answer 30

forms a copy of the DNA code

Question 31

what does tRNA do?

Answer 31

carries amino acids to the ribosomes to make protein