11 BIOLOGY

Question 1

DNA

Answer 1

The molecule that carries genetic instructions

Question 2

Chromosome

Answer 2

Threadlike structure that contains long lengths of DNA that hold many genes.

Question 3

Gene

Answer 3

Section of a chromosome that codes for one trait

Question 4

Allele

Answer 4

The different forms of a gene.

Question 5

Gamete

Answer 5

A sex cell

Question 6

Fertilisation

Answer 6

The fusion of 2 gametes

Question 7

Zygote

Answer 7

A fertilized egg cell

Question 8

Homologous chromosome

Answer 8

Have the same genes in the same loci, where one chromosome comes from the mother and one from the father.

Question 9

Meiosis

Answer 9

The type pf cell division that gametes are made by.

Question 10

sexual reproduction

Answer 10

Involves 2 individuals contributing genetically to the offspring

Question 11

asexual reproduction

Answer 11

involves 1 individual contributing genetically to the offspring

Question 12

genetic variation

Answer 12

the differences in DNA of individuals in a population/species

Question 13

continuous variation

Answer 13

where there is a complete range of measurements from one extreme to another

Question 14

Discontinuous variation

Answer 14

where the characteristics fall into a discrete categories

Question 15

genotype

Answer 15

the alleles an individual has for a trait.

Question 16

phenotype

Answer 16

the physical expression of the gene.

Question 17

dominant allele

Answer 17

the allele that is always expressed if present

Question 18

recessive allele

Answer 18

the allele that is only expressed in the homozygous condition

Question 19

homozygous

Answer 19

genotype with a two of the same alleles

Question 20

heterozygous

Answer 20

genotype with one dominant and one recessive allele.

Question 21

punnet sqaure

Answer 21

a diagram used to determine the probable outcomes of a genetic cross between 2 individuals

Question 22

pure breeding

Answer 22

an organism that is homozygous for a trait.

Question 23

test cross

Answer 23

when an individual with the dominant phenotype is crossed with a homozygous recess individual to identify if the dominant individuals genotype is heterozygous or homozygous dominant.

Question 24

natural selection

Answer 24

the process whereby organism better adapted to their environment tend to survive and produce more offspring

Question 25

mutation

Answer 25

a permanent and random change in the base sequence of DNA

Question 26

point mutation

Answer 26

occurs when a single base or very few bases is changed which affects only a single gene.

Question 27

chromosomal mutation

Answer 27

affects the whole or part of a chromosome which affects multiple genes.

Question 28

selective breeding

Answer 28

the process of choosing only plants and animals with desirable characteristics to reproduce.

Question 29

inbreeding

Answer 29

the production of offspring form the mating or breeding of individuals or organisms that are closely related genetically.

Question 30

DNA sequencing

Answer 30

is the process of identifying the exact order of the bases in a DNA strand.

Question 31

What are the 3 types of point mutation

Answer 31

Substitution: one base replaced Deletion: one base removed Insertion: one base added

Question 32

What are the 4 types of chromosomal mutation

Answer 32

Deletion: A part of a chromosome is removed Inversion: A part of a chromosome breaks off and reattaches to the same one Translocation: A part of a chromosome breaks off and reattaches to a different one Duplication: A part of a chromosome is coped

Question 33

What syndrome is affected when the chromosomes are XXY?

Answer 33

Klinefelter syndrome

Question 34

What syndrome is affected when the chromosomes are XO?

Answer 34

Turners syndrome

Question 35

What syndrome is affected when chromosomes are 21 x 3

Answer 35

Trisomy 21 (Down syndrome)

Question 36

What is haemophilia?

Answer 36

Inherited bleeding disorder in which the blood does not clot properly. This can lead to spontaneous bleeding

Question 37

What is haemophilia caused by?

Answer 37

Caused by a point mutation in gene that instructs protein 8 to clot blood

Question 38

What is cystic fibrosis

Answer 38

An inherited disorder where mucus, sweat, and digestive juicies are sticky and thick, leading to severe damage in the lungs and digestive system

Question 39

What is cystic fibrosis caused by

Answer 39

a deletion point mutation of three bases

Question 40

What is sickle cell anaemia

Answer 40

inherited disorder that affects the shape of red blood cells which can increase lack of oxygen

Question 41

what causes sickle cell anaemia

Answer 41

Substitution point mutation in the HBB gene