genetic variation, protein synthesis and mutations

Question 1

What is a gene?

Answer 1

A sequence of DNA that codes for a polypeptide or functional RNA.

Question 2

What is the structure of DNA?

Answer 2

Double helix of antiparallel strands held by hydrogen bonds between complementary bases.

Question 3

What is a chromosome?

Answer 3

A DNA molecule coiled around histone proteins, visible during cell division.

Question 4

Define genome.

Answer 4

“The complete set of genetic material in an organism.”

Question 5

Define proteome.

Answer 5

“The entire complement of proteins that can be expressed by a genome.”

Question 6

What is transcription?

Answer 6

Synthesis of mRNA from a DNA template in the nucleus.

Question 7

What is translation?

Answer 7

Assembly of a polypeptide chain at ribosomes using mRNA codons and tRNA anticodons.

Question 8

What is a point mutation?

Answer 8

A change in a single base pair in DNA.

Question 9

What is a frameshift mutation?

Answer 9

Insertion or deletion of a base that shifts the reading frame of codons.

Question 10

What is nondisjunction?

Answer 10

Failure of homologous chromosomes or sister chromatids to separate during meiosis.

Question 11

What are the products of meiosis?

Answer 11

Four genetically different haploid cells.

Question 12

What formula gives the number of genetically different gametes from independent assortment?

Answer 12

2^n (where n = haploid chromosome number).

Question 13

What is crossing over?

Answer 13

Exchange of genetic material between homologous chromosomes during prophase I.

Question 14

What is independent segregation?

Answer 14

Random distribution of maternal and paternal chromosomes into gametes.

Question 15

Define natural selection.

Answer 15

“Differential survival and reproduction of individuals due to advantageous heritable traits.”

Question 16

What is directional selection?

Answer 16

Favors individuals at one extreme of a phenotypic range.

Question 17

What is stabilizing selection?

Answer 17

Favors individuals with the average phenotype.

Question 18

How does antibiotic resistance evolve?

Answer 18

Random mutations confer resistance; antibiotics kill susceptible bacteria; resistant survivors reproduce.

Question 19

What is an adaptation?

Answer 19

A heritable trait that increases an organism’s fitness in its environment.

Question 20

What is the purpose of aseptic techniques?

Answer 20

To prevent contamination in microbial cultures during investigations.

Question 21

Name one aseptic technique used in RQP 6.

Answer 21

“Flaming the neck of a culture bottle and using sterile pipettes.”

Question 22

Define species.

Answer 22

“A group of organisms capable of interbreeding to produce fertile offspring.”

Question 23

What is courtship behavior?

Answer 23

Species-specific behaviors that help individuals identify and attract mates.

Question 24

What is the phylogenetic classification system?

Answer 24

Organizing species based on evolutionary relationships.

Question 25

List the taxa hierarchy from broadest to most specific.

Answer 25

“Domain

Question 26

What is binomial naming?

Answer 26

Two-part Latin name: Genus capitalized and species lowercase, e.g. Homo sapiens.

Question 27

What is a phylogenetic tree?

Answer 27

Diagram showing evolutionary relationships among species or groups.

Question 28

Define evolution.

Answer 28

“Change in allele frequencies in a population over time.”

Question 29

What is biodiversity?

Answer 29

The variety of life in all its forms, including genetic, species, and ecosystem diversity.

Question 30

What is species richness?

Answer 30

The number of different species present in a habitat.

Question 31

What is the index of diversity formula?

Answer 31

D = N(N−1) / Σn(n−1), where N = total individuals, n = individuals of each species.

Question 32

How do you measure genetic diversity within a species?

Answer 32

Calculate heterozygosity at gene loci or measure DNA/protein sequence variation.

Question 33

How do you measure genetic diversity between species?

Answer 33

Compare allele frequency differences or sequence divergence between populations.

Question 34

formula to calc the number of possible combinations of chromosomes following random fertilisation

Answer 34

2n squared

Question 35

process of transcription?

Answer 35

1. hydrogen bonds break by DNA helicase 2. one strand acts as a template 3. free floating RNA nucleotides attracted to complementary base pairs 4. uracil pairs with adenine, instead of thymine, in RNA 5. RNA polymerase joins adjacent RNA nucleotides 6. this forms phosphodiester bonds via condensation reactions 7. pre-mRNA formed, which is spliced to remove introns forming mature mRNA

Question 36

how does prokaryotic mRNA differ from eukaryotic mRNA?

Answer 36

no introns

Question 37

what are introns?

Answer 37

base sequences that don't code for the production of amino acids

Question 38

translation process?

Answer 38

1. mRNA attaches to a ribosome, and ribosome moves to a start codon 2. tRNA brings a specific amino acid 3. tRNA anticodon binds to complementary mRNA codon 4. ribosome moves along to next codon and another tRNA binds, so 2 amino acids can be joined by a condensation reaction, forming a peptide bond, using energy from the hydrolysis of ATP 5. tRNA released after amino acid joined polypeptide 6. ribosome moves along mRNA from the polypeptide, until a stop codon is reached

Question 39

how is each species universally identified?

Answer 39

a binomial consisting of the name of its genus and species, e.g. Homo sapiens

Question 40

taxa hierarchy order and mnemonic?

Answer 40

does king philip clamp our feet good sir domain, kingdom, phylum, class, order, family, genus, species

Question 41

what are the three types of selection?

Answer 41

disruptive, stabilising, and directional

Question 42

what is disruptive selection? and give an example

Answer 42

when the normal distribution is completely disrupted. this is bc the selection pressure towards the extremes creates two model values e.g. peppered moths

Question 43

what is stabilising selection? and give an example

Answer 43

when the environment is very stable and the majority of individuals are close to the average. this is bc selection pressure towards the centre increases the number of individuals at the modal value e.g. human birth body weight

Question 44

what is directional selection? and give an example

Answer 44

shifts to one particular direction, e.g. right or left this is bc selection pressure towards one extreme moves the mode in this direction e.g. long giraffe neck, or getting a mate

Question 45

how does the value for mean, mode and range vary for the normal distribution?

Answer 45

it is the same value for all of them

Question 46

how does narrowing the normal distribution affect the standard deviation?

Answer 46

decreases it

Question 47

what is selection pressure?

Answer 47

selection pressure are external factors that affect an organism's ability to survive in a given environment

Question 48

match the letter to a number 1) advantageous 2) disadvantageous a) selected for b) selected against

Answer 48

1) advantageous = a) selected for 2) disadvantageous = b) selected against