Topic 3: Genetics

Question 1

What is a diploid cell

Answer 1

A cell with two sets of chromosomes

Question 2

What is a haploid cell

Answer 2

A cell with one set of chromosomes

Question 3

What is meiosis

Answer 3

A type of cell division that halves the chromosome number and produces 4 genetically different haploid gametes

Question 4

Where does meiosis occur

Answer 4

In the ovaries and testes to form gametes

Question 5

Why is meiosis important

Answer 5

It ensures genetic variation and maintains chromosome number in offspring

Question 6

What is sexual reproduction

Answer 6

Reproduction involving the fusion of gametes from two parents

Question 7

What is asexual reproduction

Answer 7

Reproduction from one parent without gamete fusion producing clones

Question 8

Advantages of sexual reproduction

Answer 8

Genetic variation helps survival in changing environments

Question 9

Disadvantages of sexual reproduction

Answer 9

Slower and requires more energy and finding mates

Question 10

Advantages of asexual reproduction

Answer 10

Faster energy efficient produces many offspring quickly

Question 11

Disadvantages of asexual reproduction

Answer 11

No genetic variation so vulnerable to changes

Question 12

What is the structure of DNA

Answer 12

A double helix made of two strands of nucleotides

Question 13

What is a nucleotide

Answer 13

It contains a sugar phosphate group and a base

Question 14

What are the four DNA bases

Answer 14

Adenine Thymine Cytosine Guanine

Question 15

How do DNA bases pair

Answer 15

Adenine pairs with Thymine and Cytosine pairs with Guanine

Question 16

What is a gene

Answer 16

A section of DNA that codes for a protein

Question 17

What is a genome

Answer 17

The entire DNA of an organism

Question 18

What is a genotype

Answer 18

The combination of alleles an organism has

Question 19

What is a phenotype

Answer 19

The physical appearance caused by the genotype

Question 20

What is a chromosome

Answer 20

A long DNA molecule containing many genes

Question 21

What is protein synthesis

Answer 21

The process of making proteins from genes involving transcription and translation

Question 22

What happens during transcription

Answer 22

RNA polymerase binds to DNA in the nucleus and separates the strands

Question 23

What is mRNA

Answer 23

Messenger RNA a single stranded copy of the gene made during transcription

Question 24

How is mRNA formed

Answer 24

RNA polymerase matches RNA bases to one DNA strand using base pairing rules and creates an mRNA strand

Question 25

Where does mRNA go after being made

Answer 25

It leaves the nucleus and enters the cytoplasm to reach a ribosome

Question 26

What happens during translation

Answer 26

The ribosome reads the mRNA codons and tRNA brings matching amino acids

Question 27

What is a codon

Answer 27

A sequence of three bases on mRNA that codes for one amino acid

Question 28

What is tRNA

Answer 28

Transfer RNA it carries specific amino acids to the ribosome

Question 29

What is an anticodon

Answer 29

A set of three bases on tRNA that pairs with the codon on mRNA

Question 30

How does a protein form

Answer 30

Amino acids are joined together in the correct order to form a polypeptide chain

Question 31

What determines the order of amino acids in a protein

Answer 31

The sequence of codons on the mRNA

Question 32

What is the function of RNA polymerase

Answer 32

It builds the mRNA strand using the DNA template

Question 33

What is a mutation

Answer 33

A change in the DNA base sequence

Question 34

What is an allele

Answer 34

A different version of a gene caused by mutation

Question 35

What is the effect of a mutation in a gene

Answer 35

It may change the protein coded for and affect function

Question 36

What is the effect of a mutation in a non coding region

Answer 36

It may affect how a gene is expressed

Question 37

What did Mendel study

Answer 37

Pea plant inheritance of characteristics

Question 38

What were Mendel’s conclusions

Answer 38

Characteristics are inherited through units that do not blend and can be dominant or recessive

Question 39

Why was Mendel’s work not accepted at first

Answer 39

Genes and DNA had not been discovered yet

Question 40

What is monohybrid inheritance

Answer 40

Inheritance of one gene with dominant and recessive alleles

Question 41

How do you show inheritance patterns

Answer 41

Using genetic diagrams or Punnett squares

Question 42

What are the sex chromosomes

Answer 42

XX for females XY for males

Question 43

Why are sex linked disorders more common in males

Answer 43

Males only have one X chromosome so recessive alleles are always expressed

Question 44

What are the main blood group alleles

Answer 44

IA IB and IO

Question 45

Which blood group alleles are codominant

Answer 45

IA and IB are codominant both are expressed in AB blood group

Question 46

Which blood group allele is recessive

Answer 46

IO is recessive to both IA and IB

Question 47

What are the possible blood group genotypes for blood group A

Answer 47

IAIA or IAIO

Question 48

What are the possible blood group genotypes for blood group B

Answer 48

IBIB or IBIO

Question 49

What are the possible blood group genotypes for blood group AB

Answer 49

IAIB

Question 50

What are the possible blood group genotypes for blood group O

Answer 50

IOIO

Question 51

What causes variation

Answer 51

Differences in genes environment or both

Question 52

What is the Human Genome Project

Answer 52

A global project to map the entire human DNA sequence

Question 53

Give one advantage of the Human Genome Project

Answer 53

It helps identify genes linked to diseases and improve treatment