DNA Structure + Genes/Chromosomes

Question 1

What is DNA

Answer 1

the genetic information inside the body’s cells that helps make people who they are

Question 2

What is a nucleotide made up of?

Answer 2

Phosphate, deoxyribose sugar, and a base

Question 3

Name the 4 bases

Answer 3

Cytosine, Guanine, Adenine, Thymine

Question 4

Name the Pairs

Answer 4

C+G, A+T

Question 5

What forms a sugar-phosphate backbone?

Answer 5

A phosphate from one nucleotide forms a bond with the sugar on the next

Question 6

How are the bases held together?

Answer 6

Hydrogen bonds

Question 7

What is a double helix?

Answer 7

The 3D shape of Dna

Question 8

What are genes?

Answer 8

a segment of DNA that codes for a protein that determine your hair colour, eye colour eg.

Question 9

What are chromosomes?

Answer 9

Very tightly wound up structures of DNA

Question 10

Total amount of chromosomes?

Answer 10

46, 23 from mum, 23 from dad

Question 11

What are homologous pairs

Answer 11

two copies of every chromosomes

Question 12

What is a diploid

Answer 12

A cell or organism that contains two copies of every chromosome

Question 13

What is a haploid

Answer 13

A cell or organism that contains one copy of every chromosome. The only haploid cells in humans are sex cells.

Question 14

What is a Karyotype?

Answer 14

A karyotype is a picture of all the chromosomes in a cell, arranged in pairs. The first 22 pairs are autosomes (non-sex chromosomes), and pair 23 are the sex chromosomes.

Question 15

3 unique features of homologous chromosomes

Answer 15

1. size
2. banding pattern
3. centromere position

Question 16

Trisomy 21

Answer 16

• Extra chromosome #21
• 47 Chromosomes
• Down Syndrome
• Small limbs, almond shaped eyes

Question 17

Klinefelter’s syndrome

Answer 17

• XXY
• 47 Chromosomes
• Only in males
• tall, sterile, small testicles, appear normal

Question 18

Turner’s syndrome

Answer 18

• Single X in female
• 45 Chromosomes
• Short webbed neck
• Sterile

Question 19

What are alleles

Answer 19

Different versions of the same gene.

Question 20

Genotype

Answer 20

The particular combination of alleles of a gene. Can be homozygous or heterozygous.
- Homozygous: two of the same allele ( BB or bb )
- Heterozygous: one of each allele ( Bb )

Question 21

Phenotype

Answer 21

The visible expression of. genotype

Question 22

How is your phenotype affected by the environment

Answer 22

Phenotype = genotype + environment. your genotype may cause you to have fair skin, but in summer your skin may darken. This is the influence of the environment.

Question 23

Dominant trait

Answer 23

Requires only one allele for the trait to show in the phenotype. Shown by one or two capital letter ( BB or Bb )

Question 24

Recessive trait

Answer 24

Needs two copies of an allele before it shows in the phenotype. ( bb )

Question 25

carriers

Answer 25

Have an allele for the recessive trait in their genotype, but do not show the trait in their phenotype. (ARGP)

Question 26

amino acid

Answer 26

A small molecule that joins with others to form proteins

Question 27

protein

Answer 27

a large molecule made up of amino acids

Question 28

trait

Answer 28

your physical characteristics , Traits include height, hair colour, skin colour and freckles

Question 29

How many chromosomes does human gametes have?

Answer 29

23 chromosome in each

Question 30

scientists involved in the discovery of the DNA structure

Answer 30

Watson, Crick and Wilkins

Question 31

pure breeding

Answer 31

the parents with a particular phenotype produce offspring only with the same phenotype.

Question 32

homozygous

Answer 32

having two identical alleles for a particular trait.

Question 33

heterozygous

Answer 33

having two different alleles for a particular trait