DNA and genetics

Question 1

what does the dna structure look like?

Answer 1

double helix/twisted ladder shape

Question 2

what are nucleotides?

Answer 2

The basic structural unit of DNA, consisting of a deoxyribose sugar, a phosphate and a nitrogen base

Question 3

what are the base pairs?

Answer 3

T & A
C & G
A & T
G & C

Question 4

how many hydrogen bonds are there when thymine and adenine bond?

Answer 4

2

Question 5

how many hydrogen bonds are there when cytosine and guanine bond?

Answer 5

3

Question 6

how many chromosomes and pairs are there in every cell?

Answer 6

46 chromosomes and 23 pairs

Question 7

what do chromosomes consist of?

Answer 7

segments of dna known as genes

Question 8

what are the 2 basic functions of dna?

Answer 8

1. carry genetic information for inheritance

2. coding for amino acids to produce proteins

Question 9

what is the process of copying dna called? what is it?

Answer 9

• this process is called dna replication
• to do this strands of the double helix must separate/zip
• the bases of the exposed strands pair up with free nucleotides forming new strand

Question 10

what is a specific characteristic of dna replication that must be correct?

Answer 10

every cell must have identical dna to the original body cell

Question 11

what does dna and rna stand for?

Answer 11

deoxyribonucleic acid & ribonucleic acid

Question 12

what does protein synthesis do?

Answer 12

• holds instructions for every protein
• process of making proteins in the cell
• proteins are made up of amino acids

Question 13

where do we get our supply of amino acids from? how many are there?

Answer 13

From the food we eat & 20 amino acids total

Question 14

what is a group of three bases on dna stand called?

Answer 14

Codon = codes for 1 amino acid

Question 15

what is copied into rna and why?

Answer 15

dna cannot leave the nucleus, so it has to be copied into rna which is only single stranded and small enough to leave the nucleus through the nuclear pores

Question 16

where does protein synthesis happen?

Answer 16

ribosomes

Question 17

what do the ribosomes do?

Answer 17

reads the rna in groups of 3 bases and signals for the matching amino acid

Question 18

what does the order of the bases determine?

Answer 18

order of amino acids in the protein

Question 19

what is mRNA & tRNA

Answer 19

mRNA is transcripted from dna & tRNA is translated from mRNA - amino acids attached to it

Question 20

what is an organelle?

Answer 20

a membranous structure within a cell, specialised for a particular function

Question 21

what is a chromosome?

Answer 21

A rod like structure that contains dna, which makes up the genes of an individual

Question 22

what is a gene?

Answer 22

The factor that determines an inherited characteristic, located in the chromosomes

Question 23

what is a trait?

Answer 23

an inherited feature of an organism

Question 24

what is evolution?

Answer 24

the gradual change in the characteristics of a species over a period of time

Question 25

what is natural selection?

Answer 25

the process by which species becomes better adapted to its environment