Inheritance

Question 1

What is a genome

Answer 1

The entire DNA of a molecule

Question 2

What is a gene and where are they located

Answer 2

A section of a molecule that codes for a specific protein (amino acids)

In chromosomes

Question 3

Where are chromosomes located

Answer 3

In the nucleus

Question 4

What is DNA

Answer 4

two strands coiled to form a double helix

Question 5

What are the 4 bases and their pairs

Answer 5

adenine (A) with thymine (T)

cytosine (C) with guanine (G)

Question 6

How many strands is RNA

Answer 6

1

Question 7

What is the difference between RNA and DNAs bases

Answer 7

RNA contains uracil (U) instead of thymine (T)

Question 8

How does protein synthesis work

Answer 8

https://igcse-biology-2017.blogspot.com/2017/06/318b-describe-stages-of-protein.html

Question 9

• 3.34 understand that mutation is a rare, random change in genetic material that can be inherited

Answer 9

you already know that!!!

Question 10

• 3.35B understand how a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein
• 3.36B understand how most genetic mutations have no effect on the phenotype, some have a small effect and rarely do they have a significant effect

Question 11

How can mutation likelyhood be increased

Answer 11

exposure to ionising radiation (for example, gamma rays, x-rays and ultraviolet rays) and some chemical mutagens (for example, chemicals in tobacco)

don’t need to know all example

Question 12

• 3.31 understand how random fertilisation produces genetic variation of offspring

Answer 12

As random genotypes are taken from each parent

Question 13

how many diploid and haploid chromosomes are their

Answer 13

Diploid = 46
Haploid=23

Question 14

What are the two causes of genetic variation

Answer 14

• environmental
• genetic
  (- a mix of both)

Question 15

What other form do genes exist in

Answer 15

Alleles

Question 16

What does dominant mean when referring to an allele

Answer 16

An allele that will always express itself in the phenotype (only requires one allele)

Question 17

What does recessive mean when referring to an allele

Answer 17

An allele that will only express itself in the phenotype if partnered with another recessive allele ( requires two alleles)

Question 18

What does homozygous mean when referring to an allele

Answer 18

When an individual has two identical Alleles of a Gene (two of dominant or recessive)

Question 19

What does heterozygous mean when referring to an allele

Answer 19

When an individual has two different Alleles of a Gene

Question 20

Phenotype definition

Answer 20

Th physical manifestation of a genotype

Question 21

Genotype definition

Answer 21

The genetic makeup of an individual regarding alleles

Question 22

• 3.23 describe patterns of monohybrid inheritance using a genetic diagram
• 3.25 predict probabilities of outcomes from monohybrid crosses

Answer 22

https://www.savemyexams.com/igcse/biology/edexcel/19/revision-notes/3-reproduction-and-inheritance/inheritance/monohybrid-inheritance-genetic-diagrams/

Question 23

What shape is a female and what shape is a man in a pedigree diagram

• 3.24 understand how to interpret family pedigrees

Answer 23

Man - square
Woman - circle

https://igcse-biology-2017.blogspot.com/2017/06/324-understand-how-to-interpret-family.html#google_vignette

Question 24

How many sets of chromosomes is the sex of a person controlled by
+
what chromosomes are for a male and for a woman

Answer 24

1 set
Man = XY
Woman = XX

Question 25

Codominance meaning

Answer 25

both alleles within a genotype are expressed in the phenotype of an individual (both are dominant)

If heterozygous (2 different alleles) then a mix of the two (a third option) is shown in the phenotype

E.g:
RR = Red plant
WW = White plant
RW = Pink plant

Question 26

What is Darwins theory of evolution

Answer 26

The organisms that have mutations which give them an advantage to survive outlive the other organisms and therefore reproduce more, passing on their beneficial mutation over many generations until most organisms have it.

Question 27

How can resistance to antibiotics increase in bacterial populations

Answer 27

As bacteria develop MUTATIONS? which then are passed down generations when they survive longer and reproduce