Topic 6 Inheritance, variation and evolutio

Question 1

What is asexual reproduction?

Answer 1

Between 1 plant or animal through mitosis so like clones of the parent.

Question 2

What is sexual reproduction?

Answer 2

Sexual between a sperm and egg cell or plant cells and pollen. Fusion of gametes to make 46 chromosomes (23 pairs) 23= 1 gamete. Suse together through meiosis so not genetically identical. Mother one set father other set.

Question 3

What happens in meiosis?

Answer 3

Not geneteically identical produces 4 daughter cells produce gametes and the chromosome number is reduced by half.

Question 4

What are some advantages of sexual reproduction?

Answer 4

Allows for selective breeding which is developing the offspring to have a certain characteristic which are desirable alike to 2 animals with lots of meat.
Provides variation so if a species is more likely to survive if enviromental conditions change.

Question 5

What is a gene?

Answer 5

Small section of DNA in a chromosome with a triplet of bases.

Question 6

What is a chromosome?

Answer 6

Small section of DNA found in the nucleus .

Question 7

Different types of alleles.

Answer 7

Dominant or recessive

Question 8

What does heterozygous mean?

Answer 8

1 dominant allele and recessive allele

Question 9

What does homozygous mean?

Answer 9

2 recessive alleles

Question 10

What is cystic fybrosis?

Answer 10

A disorder of cell membranes resulting in a thick nucleus forming.

Question 11

What does embryonic screening do?

Answer 11

It is to check for disorders to be either extracted or developed in a lab.

Question 12

What are some adv. of embryonic screening?

Answer 12

Many regulations to stop it getting out of hand.
Prevents a disorder.

Question 13

What are some dis. of embryonic screening?

Answer 13

Gives the idea that with that disorder they won’t live a full life / unwanted lead to changing of characteristics designer babies
Very expensive
Lead to miscarriage decisions about terminating the pregnancy.

Question 14

How is the sex determined?

Answer 14

By a punnett square

Question 15

What pair carries the sex genes?

Answer 15

23rd pair XY or XX

Question 16

What’s female or male symbols?

Answer 16

XX for female
XY for male

Question 17

What 2 things affect the phenotype?

Answer 17

Genotype - so the genes inherited providing genetic variation never the same except in twins by mother and father.

Question 18

What is genetic variation caused by?

Answer 18

Mutations in a sequence of DNA doesn’t usually affect the phenotype but if it does and if it is advantageous then natural selction makes it the common phenotype.

Question 19

What can variation be affceted by?

Answer 19

Variation in the enviroment e.g. weight.

Question 20

What’s eveolution caused by?

Answer 20

Mutations if they are advantageous.

Question 21

Define evolution.

Answer 21

Change in inherited characteristics by Natural selection may = new species.

Question 22

What is the theory of evolution?

Answer 22

All species evolved from simple life billions of years ago.

Question 23

What is speciation?

Answer 23

When a species become infertile and are new species.

Question 24

What is selective breeding?

Answer 24

Parents with a desired characteristic are bred with parents also with that characteristic. Eg. lots of meat/ plant disease resistant.

Question 25

What are the dis. of selective breeding?

Answer 25

Reduces the gene pool so less different alleles = easily wiped out because no variation.

Question 26

What is genetic engineering?

Answer 26

Modyfying the genome by introducing a gene from another organism = desired characteristic.

Question 27

How does genetic engineering work?

Answer 27

Genes from chromosomes are cut out Plasmids alos cut out Loop and genes stuck together Placed in a vector = multiply and contains modified gene.

Question 28

What are some adv. of genetic engineering?

Answer 28

Larger yield of crops Vitamins can grow where they usually wouldn't Larger crops = less world hunger Mass produce in medicine

Question 29

What are some dis. of genetic engineering?

Answer 29

Health risks are unknown Infertility can spread to wild plants and damage the enviroment Can be used in babies to create designer babies Selection pressure

Question 30

Explain the process of fossils.

Answer 30

1. remains fall to the bottom of the sea where rock and mud form on top so no oxygen or moisture they turn to rock under the pressure. 2. Teeth, shells and bones turn to rock 3. Footprints are formed as a cast around them

Question 31

What are fossils?

Answer 31

Remains of organisms from millions of years ago found in rocks.

Question 32

Whats the difference between soft bodied animals and hard bodied animals in fossilisation?

Answer 32

Soft bodied don't turn and are destroyed by geological activity.

Question 33

What is extinction caused by?

Answer 33

Change of habitat Catastrophic event New disease arises no resitant alleles Organism with more advantageous mutations competing for the same food source. Destruction of habitat

Question 34

Define extinction.

Answer 34

When an entire species has died out.

Question 35

Define resistant bacteria.

Answer 35

When bacteria that was once cured by an antibiotic isn't killed.

Question 36

What is selective pressure?

Answer 36

Bacteria reproduces at a fast rate so advantageous mutations are passed on and the population increases rapidly and mutations spreads rapidly.

Question 37

What can't antibiotics be used against?

Answer 37

Can't be used for viral infections have to be taken for full course. Specific antiobiotic = specicfic bacteria Used less in agriculture.

Question 38

How can less resistant bacteria be developed?

Answer 38

Disposable clothing or regularly sanitised increase standards of hygiene Regularly washing hands.

Question 39

How can the classification of living organisms be shown?

Answer 39

Evolutionary trees.

Question 40

What is the classification of living organsims?

Answer 40

Kingdom Phylum Class Order Family Genus Species

Question 41

3 main groups of classification of living organisms?

Answer 41

Archae Bacteria Eukaryota

Question 42

3 main groups of classification of living organisms?

Answer 42

Archae Bacteria Eukaryota

Question 43

Who invented the classification of living organisms?

Answer 43

Carl linneaus in the 1700s.