DNA and genes

Question 1

what is genetic information?

Answer 1

a chemical blueprint that codes for characteristics of an organism

Question 2

what does a DNA molecule contain?

Answer 2

bases which are arranged in complementary pairs. DNA transcripts into RNA and then translated into protein.

Question 3

how many chromosomes do most humans have?

Answer 3

46 individual chromosomes

Question 4

when does fertilization occur?

Answer 4

when a sperm fuses with an egg

Question 5

what is the difference between recessive and dominant characteristics?

Answer 5

the dominant characteristic always masks the recessive characteristic (eg AA, Aa will have a a phenotype of A)

Question 6

what is the difference between mitosis and meiosis?

Answer 6

mitosis has 2 identical daughter cells that contain 46 chromosomes and produce body cells.

meiosis has 4 non-identical daughter cells that contain 23 chromosomes and produce sex cells.

Question 7

what are the phases of mitosis?

Answer 7

prophase, metaphase, anaphase, telophase

Question 8

what happens in mitosis?

Answer 8

Interphase is the preparation for cell division, it replicates the chromosomes.
Prophase is when DNA condenses to form chromosomes
Metaphase is when the chromosomes line up
Anaphase is when the chromosomes split up
Telophase is when the nucleus reforms

Question 9

what phase sets up mitosis?

Answer 9

interphase

Question 10

what is the longest phase of the cell cycle?

Answer 10

interphase

Question 11

what is a phenotype?

Answer 11

the physical appearance of the genes (eg blue eyes, black hair)

Question 12

what is a genotype?

Answer 12

the genes of an organism. (eg AA, Aa, aa)

Question 13

how are females and males represented on a pedigree? how do you interpret a pedigree?

Answer 13

circle for female, square for male.

Question 14

what is the difference between heterozygous and homozygous?

Answer 14

hetrozygous is when the alleles are different (Aa). homozygous is when the alleles are the same (AA, aa)

Question 15

what is the complementary pairing of bases?

Answer 15

A and T, G and C

Question 16

what does DNA stand for?

Answer 16

deoxyribonucleic acid

Question 17

what is the structure of DNA?

Answer 17

DNA is two nucleotide strands that wound together to form a double helix shape

Question 18

what is the difference between DNA and RNA?

Answer 18

DNA has 2 stands and has thymine (T)

RNA is single stranded and has Uracil (U)

during DNA transcription A complementary pairs to U

Question 19

if the first base triplet has a mutation occurring with adenine being replaced by cytosine. What effect will it have on the amino acid coded for?

Answer 19

this will change the amino acid

Question 20

what is a gene made up of?

Answer 20

a gene is made up of DNA

Question 21

what is an allele?

Answer 21

a different type of gene

Question 22

how is the cross between two heterozygous white sheep shown on a punnet square?

Answer 22

W on the top left, w on the top right, W on the top left side, w on the bottom left side. then work out the percentages.

Question 23

what are haploid cells?

Answer 23

sex cells

Question 24

what are diploid cells?

Answer 24

body cells

Question 25

what are chromosomes?

Answer 25

they are found in the nucleus

Question 26

what makes up a nucleotide?

Answer 26

phosphate group, pentose sugar, nitrogenous base,

Question 27

what is X X and X Y?

Answer 27

XX = female, X Y = male

Question 28

the name of the building block for DNA?

Answer 28

nucleotide

Question 29

what is the outcome of mitosis?

Answer 29

cytokinesis

Question 30

what is the percentage of all bases in a molecule?

Answer 30

C and G = 15% A and T = 35%

Question 31

what is the function of DNA?

Answer 31

DNA determines the structure and functioning of an organism.

DNA can track back genes and inheritance

Question 32

what are the building blocks of protein?

Answer 32

amino acids

Question 33

what are genes?

Answer 33

genes are inherited by parents and determine someones characteristics