Inheritance, variation and evolution

Question 1

Does meiosis lead to identical cells or non identical cells being formed?

Answer 1

Non identical cells

Question 2

What does sexual reproduction involve?

Answer 2

The fusion of male and female gametes

Question 3

What is asexual reproduction between flowering plants?

Answer 3

Pollen and egg cells

Question 4

Why in sexual reproduction is there a variety of offspring?

Answer 4

There is a mix of genetic information

Question 5

Why in asexual reproduction is there not a variety of offspring?

Answer 5

Only one parent, Therefore no mixing of genetic information

Question 6

What does meiosis do to the chromosomes in gametes?

Answer 6

Halves them

Question 7

What does fertilisation do?

Answer 7

Restore the full number of chromosomes

Question 8

What do cells in reproductive organs form into?

Answer 8

Gametes

Question 9

In meiosis how many times does a cell divide, and how many gametes does that form?

Answer 9

Divides twice to form four gametes

Question 10

Where is DNA found in a cell?

Answer 10

In the genetic material of the nucleus

Question 11

What is DNA?

Answer 11

A polymer

Question 12

What is DNA made up of?

Answer 12

Two Strands forming a double helix.

Question 13

What is DNA contained in?

Answer 13

Chromosomes

Question 14

What is a gene?

Answer 14

A small section of DNA on a chromosome

Question 15

What does each gene do?

Answer 15

Codes for a particular sequence of amino acids, to make a specific protein

Question 16

What is the Genome of an organism?

Answer 16

The entire genetic material of the organism

Question 17

What is the importance of understanding the human Genome?

Answer 17

We can search for genes linked to different types of disease

Understand and treat inherited disorders

We can use it to trace human migration patterns from the past

Question 18

What is an allele?

Answer 18

Different versions of the same gene

Question 19

What is homozygous?

Answer 19

alleles that are both identical for the same characteristic

Question 20

What is heterozygous?

Answer 20

alleles that are both different for the same characteristic

Question 21

What is a genotype?

Answer 21

the collection of alleles that determine an organism’s characteristics

Question 22

What is a phenotype?

Answer 22

The particular version of a characteristic seen in an individual

Question 23

Are dominant alleles, always expressed, or sometimes only expressed if two copies are present?

Answer 23

Always

Question 24

How are disorders inherited?

Answer 24

By the inheritance of certain alleles

Question 25

What is the disorder polydactyly caused by?

Answer 25

A dominant allele

Question 26

What is cystic fibrosis caused by?

Answer 26

Recessive allele

Question 27

What are the advantages of embryo screening?

Answer 27

It will help to stop people from suffering

Question 28

What are the disadvantages of embryo screening?

Answer 28

Costs the government a lot of money

Question 29

How many chromosomes do ordinary human body cells contain?

Answer 29

23 pairs 46. Chromosomes.

Question 30

What do the 22 pairs of the chroma zones in the human body control?

Answer 30

Control characteristics only

Question 31

What do 1 of the pairs out of the 23 pairs of chromosomes in a human body carry?

Answer 31

Carry’s the genes that determine sex

Question 32

In females, are the sex chromosomes, the same or different?

Answer 32

The same

Question 33

In males are the chromosomes, the same or different

Answer 33

Different

Question 34

What is variation?

Answer 34

Differences in the characteristics of individuals in a population

Question 35

What are causes of variation?

Answer 35

The genes they have inherited They conditions in which they have developed Combination of genes and environment

Question 36

When do mutations occur?

Answer 36

Continuously

Question 37

What is evolution?

Answer 37

Change in the inherited characteristics of a population over time for a process of natural selection, which may result in the formation of a new species

Question 38

What does the theory of evolution state?

Answer 38

All species of living things have evolved from simple life forms that first developed more than 3 billion years ago

Question 39

How does evolution occur?

Answer 39

Natural selection of variants that give rise to the phenotype, best suited to the environment

Question 40

What is selective breeding?

Answer 40

The The process by which Humans breed plants in animals for particular genetic characteristics

Question 41

What are some examples of selective breeding?

Answer 41

Disease resistance in food crops, animals which produce more meat and milk, domestic dogs with a gentle nature, large or unusual flowers

Question 42

What Can selective breeding lead to?

Answer 42

Inbreeding

Question 43

What is genetic engineering?

Answer 43

The process which involves modifying the genome of an organism by introducing a gene from another organism to give a desire characteristic

Question 44

What is an example involving a bacteria cell which has been genetically engineered?

Answer 44

Bacteria cells engineer to produce useful substances such as human insulin to treat diabetes

Question 45

What are GM crops?

Answer 45

Crops that are resistant to insect attack or two herbicides and generally Show increased yields

Question 46

What are some concerns about GM crops?

Answer 46

The effect on the populations of wildflowers and insects, some people feel the effects of eating GM crops and human health have not been fully explored

Question 47

What are the main steps in the process of genetic engineering?

Answer 47

1. Enzymes are used to isolate the required gene, This gene is inserted into a vector usually a bacterial plasmid or a virus 2.The vector used to insert the gene into the required cells 3. Genes are transferred to cells of the animals, plants or microorganisms an early stage in a development develop with desired characteristics

Question 48

What are the 2 Pieces of evidence we have for evolution?

Answer 48

Fossils And antibiotic resistance in bacteria

Question 49

What are fossils?

Answer 49

Remains of organisms from millions of years ago which are found in rocks

Question 50

How are fossils formed?

Answer 50

From parts of organisms that have not decayed because one or more of the conditions needed for decay are absent

Question 51

Why can scientists not be certain about how life began on Earth?

Answer 51

Many early forms of life is softbodied, which means that they have left few traces behind What traces there were have been mainly destroyed by geological activity

Question 52

What can we learn from the fossils?

Answer 52

How much or how little different organisms have changed as life has developed on

Question 53

When do extinctions occur?

Answer 53

When there are no remaining individuals of species still alive

Question 54

Why can bacteria evolve rapidly?

Answer 54

Because they reproduce at a fast rate

Question 55

What do mutations of bacterial pathogens produce?

Answer 55

New strains

Question 56

What is one example of a bacteria resistant to antibiotics?

Answer 56

MRSA

Question 57

How can they reduce the rate of development of antibiotic resistant strains?

Answer 57

Doctors should not prescribe antibiotics inappropriately such as treating non-serious or viral infections

Question 58

What is a disadvantage of Developing new antibiotics?

Answer 58

Costly and slow

Question 59

What is Linnaeus’s Classification?

Answer 59

Kingdom Phylum Class Order Family Genus Species

Question 60

How organisms named by Carl Linnaeus?

Answer 60

By the binomial system of genius and species

Question 61

What is the three-domains system developed by Carl woese ?

Answer 61

Archaea Bacteria Eukaryota

Question 62

What is binary fission ?

Answer 62

Reproduction in bacteria

Question 63

What is the genotype of male offspring ?

Answer 63

XY

Question 64

What is the genotype for female offspring ?

Answer 64

XX