Dna replication, protein synthesis, mutations and gene editing

Question 1

What enzymes are used for DNA replication?

Answer 1

Helicase (unwinds the DNA)
Polymerase (catalyse synthesis of the new DNA strand)
Primase (initiates new DNA synthesis)
Ligase (joins okaraki fragments and seals other nicks in the sugar phosphate backbone)

Question 2

Stages of DNA replication

Answer 2

1. DNA unwinds at the origin of replication (Helicase)
2. New strands of DNA are synthesized by DNA polymerase using the parental DNA as a template
3. Replication is completed, and two new DNA molecules are separated

Question 3

PCR stands for

Answer 3

polymerase chain reaction

Question 4

What is PCR

Answer 4

a technique of replicating DNA under laboratory conditions.

Question 5

Why is PCR used

Answer 5

it is crucial for studies and diagnostics where only a small DNA sample may be available because it can make millions of copies.

Question 6

where is PCR used

Answer 6

to diagnoce diseases, clone and sequence genes

Question 7

what is electrophoresis

Answer 7

It is a technique used to separate and analyze charged molecules, such as DNA, RNA, or proteins, based on their mobility in an electric field.

Question 8

What is the principle of electrophoresis

Answer 8

The basic principle involves applying an electric current to a gel containing the molecules of interest. The charged molecules move through the gel at different rates. This separation allows for the visualization and analysis of the molecules based on their size, charge, or other characteristics.

Question 9

DNA profiling is

Answer 9

a technique by which individuals can be identified and compared via their respective DNA profiles

Question 9

Transcription is

Answer 9

the process by which the genetic information encoded in DNA is copied into RNA

Question 10

mRNA

Answer 10

a type of RNA that carries gen. info. from DNA in the nucleus to the ribosomes in the cytoplasm/nucleus, where it is used as a template to synthesize proteins.

Question 11

stages of transcription

Answer 11

1. Initiation: RNA binds to the promoter region of DNA. Promoter gives rignal and RNA polumerase unwinds the double helix
2. Elongation: RNA polymerase moves along the DNA template strand and synthesizes a complimentary RNA strand. (5’ to 3’ direction)
3. Termination: marks the end of transcription

Question 12

WHat enzymes r used during transcription?

Answer 12

RNA polymerase, DNA helicase

Question 13

difference between DNA replication and transcription

Answer 13

Enzyme: replication - DNA polymerase, transcription - RNA polymerase.
Function: replication - makes identical copy of DNA, transcription - synthesizes RNA molecules using DNA as a template
End product: replication - two identical DNA strands. Transcription - RNA molecule

Question 14

role of mRNA in translation

Answer 14

carries the genetic information from DNA to ribosomes

Question 15

role of tRNA in translation

Answer 15

brinds amino acids to the ribosome during protein synthesis

Question 16

role of ribosomes in translation

Answer 16

serve as the site in protein synthesis

Question 17

Gene mutation (definition)

Answer 17

a change in the nucleotide sequence of a section of DNA coding for a specific trait

Question 18

Types of gene mutations

Answer 18

*Beneficial mutation - create new variations of a trait. Enchances organisms ability to adapt to new environment.
*harmful mutations - have negative consequences, they can cause disease ect.
*Neutral mutations - have no effect on the functioning of a specific feature.

Question 19

explain the effects of gene mutations occurring in germ cells

Answer 19

passed on to offspring, affecting an entire organism

Question 20

explain the effects of gene mutations occurring in somatic cells.

Answer 20

limited to the individual organism where mutation occurrs

Question 21

Chromosome structure

Answer 21

Two sister chromatics are attached at a compressed region called the CENTROME (middle of the chromosome), short arm and long arm and at the ends telomere

Question 22

Types of chromosomes

Answer 22

Homologous - maternal and paternal chromosome pairs
Autosomes and sex chromosomes - body chromosomes and ones that determine sex

Question 23

a karyotype is

Answer 23

an individual’s collection of chromosomes

Question 24

A karyogram

Answer 24

shows the chromosomes of an organism in homologous pairs of decreasing length

Question 25

purpose of karyogram

Answer 25

determines gender of an unborn child, tests for chromosomal abnormalities

Question 26

explain why meiosis is a reduction division

Answer 26

Because it reduces the chromosome number in half, producing haploid cells (gametes) from diploid cells.

Question 27

meiosis is

Answer 27

a cell division in sexually reproducing organisms.

Question 28

Diploid vs haploid

Answer 28

diploid contains normal amount of chromosomes (2n) and haploid half the normal number (n)

Question 29

Stages of meiosis

Answer 29

Has to rounds Meiosis I and Meiosis II and each contains stages of prophase, metaphase, anaphase, telaphase, cytokinesis

Question 30

Non-disjunction is

Answer 30

a cellular error during cell division, where chromosomes fail to separate properly and cause an unequal distribution of genetic information in daughter cells.

Question 31

Causes of non-disjunction

Answer 31

chromatids fail to separate properly

Question 32

Consequences of nin-disjunction

Answer 32

Impact on fertility, trisomy, monosomy, genetic disorders like down syndrome or turner disorder

Question 33

how does meiosis generate genetic diversity?

Answer 33

Meiosis generates genetic diversity through independent assortment, crossing-over, and random fertilization. These processes result in unique combinations of alleles in gametes, contributing to the variability of genetic traits in offspring.