Topic 6(Inheritance, variation and evolution)

Question 1

DNA

Answer 1

deoxyribonucleic acid. Chemical that all of the genetic material in a cell is made up from.
Contains coded information- instructions to put a organism together to make it work
Makes up your inherited characteristics.

Question 2

where is DNA found

Answer 2

Found in the nucleus of animal and plant cells , in structures called chromosomes
Chromosomes normally come in pairs
Is a polymer. Made up of two strands coiled together in the shape of a double helix.

Question 3

Gene

Answer 3

small section of DNA found on a chromosome.
Controls which characteristics you develop.
Different version of genes are known as alles.

Question 4

Genome

Answer 4

Genome is the entire set of genetic bacterial in an organism

Question 5

advantages of genomes

Answer 5

allows scientists to identify genes in the genome that could be linked to different types of disease, which could help understand the disease and how to treat it.

Question 6

Sexual reproduction

Answer 6

Where genetic information from two organisms are combined to produce a offspring which are genetically different to either parent

Question 7

Gametes

Answer 7

Sex cells

Question 8

Asexual reproduction

Answer 8

There is only one parent and their offspring is identical.
Happens by mitosis(A ordinary cell dividing into two)
Creates a ‘clone’

Question 9

Meiosis

Answer 9

1. A cell duplicates it’s genetic information
2. The cell lines up in the middle and splits

Question 10

Chromosomes

Answer 10

23 pairs of it in every human body cell.
22 matched pairs carry characteristics
23rd pair are labelled XX or XY
These decides your sex, male or female
Females are XX and males are XY
Sperm already have X so there is a 50% of being male or female.

Question 11

Alleles

Answer 11

Versions of genes.
If an organism has two alleles that are the same, then that trait is homozygous.
If they are different then that trait is hetrozygous.

Question 12

Characteristics

Answer 12

In order to display recessive characteristics, both alleles must be recessive.
In order to display dominant characteristics, only one allele must be dominant.

Question 13

Genotype

Answer 13

The combination of all your alleles,

Question 14

Variation

Answer 14

The same organisms but with different features, such as hair colour.
Two types, genetic and variation.

Question 15

Examples of genetic variation

Answer 15

If it is inherited
Effects the Phenotype(the characteristics it displays)

Question 16

Phenotype

Answer 16

Displayed characteristics

Question 17

Mutations

Answer 17

Changes the genome

Question 18

Evolution

Answer 18

Theorized by Charles Darwin.
Believed that organisms for the most suitable characteristics for the environment would be more likely to survive, and that organisms that have less suited characteristics for the environment would struggle to survive.

Question 19

Speclation

Answer 19

when the phenotype in a organism so much it creates a new species.

Question 20

reasons for extinction

Answer 20

The environment changes too much.
A predator kills them all.
A new disease kills it
They cannot compete with other species for food
Examples include dodos.

Question 21

Selective breeding

Answer 21

Artificially selecting to increase certain characteristics, such as being disease resistant, producing lots of meat by being bigger and to increase the amount of something rare.
The more generations of it the stronger the traits become.

Question 22

Issues with selective breeding

Answer 22

reduces the gene pool which means that it is much riskier for them to catch a disease.

Question 23

Genetic engineering

Answer 23

Transfering a gene for desirable characteristics from one organism to another.

Question 24

How does Genetic engineering work

Answer 24

The desired gene is isolated from one organism’s genome using enzymes and is inserted into a vector. The vector is usually a virus or bacterial plasmid. The vector is then inserted into the targeted organism.

Question 25

Fossils

Answer 25

Remains of organisms from thousands of years ago.
Usually found in rocks and are used to show how much or how little organisms have changed or evolved.

Question 26

How are fossils formed

Answer 26

By slowly getting replaced by minerals to form a rock-like substance.
By being burried in a soft material, such as clay, which then hardens.
By preservation in places where there is no decay.

Question 27

Bacteria

Answer 27

Can develop random mutations which can lead to changes in the bacteria’s characteristics, meaning it could become resistant to a anti-biotic.
To make matters worse, they are rapid at reproducing, meaning they can evolve quickly.

Question 28

Classification

Answer 28

Organising living organisms into groups.

Question 29

Kingdom

Answer 29

Living things are divided into kingdoms
Then subdivided into smaller groups, phylum, class, order, family, genus and species.

Question 30

organism

Answer 30

Named according to the binomial system