evolution

Question 1

pneumonic for naming species

Answer 1

Keep Ppl Close Or Forever Go Solo
Kingdom
Phylus
Class
Order
Family
Genus
Species

Question 2

Examples of environmental variation

Answer 2

Examples of environmental variation = scars, shades of skin tone

Question 3

Examples of genetic variation

Answer 3

Examples of genetic variation = eye colour, nose shape, dimples

Question 4

what feature in humans can be affected by both gender and enviroment

Answer 4

Height and weight can be affected by both gender and environment

Question 5

who are the only genetically identical humans and why

Answer 5

Twins are the only genetically identical humans - as they are from the same zygote

Question 6

what is Natural selection

Answer 6

Natural selection - when organisms gain an advantage and so become more likely to survive and breed

Question 7

why does variation occur

Answer 7

Variation occurs due to inherited genes that arise through meiosis and sexual reproduction

Question 8

what is the Theory of evolution

Answer 8

Theory of evolution: all species evolved form simple life forms that developed more than 3 billion years ago

Question 9

summarise of the evolution process:

Answer 9

Summary of the evolution process:
1. individuals within a species show a wide range of phenotypes and genetic variations
2. those with characteristics better suited to the environment are more likely to survive and can pass on their alleles to the next generation

Question 10

how do we know when a species has seperated

Answer 10

When two populations of one species become so different they can no longer interbreed to produce fertile offspring, they become two different species

Question 11

what is selective breeding

Answer 11

selective breeding = breeding two organisms with desirable characteristics

Question 12

what is selective breeding used for

Answer 12

Selective breeding is used for features like:
1. animals that produce more meat or milk
2. plants that lead to a higher yield
3. large, unusual, brightly coloured or heavily scented flowers
4. domestic dogs and farm animals with a gentle nature

Question 13

limitations of selective breeding

Answer 13

Limitations:
1. the number of alleles in a population decreases greatly, decreasing variation, meaning they can’t survive in a change of environment (a new pathogen, a change in temperature) –> population can die out
2. Inbreeding = when populations are so closely bred that the animals are bred with close relatives –> reduces variation –> some breeds are particularly prone to diseases or inherited defects

Question 14

what is genetic engineering

Answer 14

Genetic engineering = gene for a desirable characteristic is cut out of the cell of one organism and transferred to the cells of another

Question 15

process for genetic engineering

Answer 15

Process of genetic engineering:
Enzymes are used to isolate and cut out a desired gene from an organism
Gene is inserted into a vector (bacteria plasmid/virus) using more enzymes
Vector is used to insert gene into desired cells
Genes are transferred to cells when they are at an early stage of development (egg or very early embryo in animals)

Question 16

what can be made with genetic engineering

Answer 16

insulin and human growth hormones can be made with genetic engineering - there’s a limit to the proteins that bacteria can make

Question 17

examples of GM crops

Answer 17

Genetically Modified crops (GM crops) can directly increase the size of a fruit or its nutritional value
Examples of GM:
potatoes have more starch and are resistant to common pests
2. soyabeans have a healthier balance of fatty acids
3. rice plants can withstand long periods of time in water
4. some grasses can absorb and break down explosive residue in soil

Question 18

what is a clone

Answer 18

clone = an individual that has been produced asexually and is genetically identical to the parent

Question 19

explain tissue culture

Answer 19

Tissue culture - a type of cloning:
use a mixture of plant hormones and conditions to stimulate each cell to form a new plant - it’s mostly used to preserve rare plants
They produce a mass of identical plant cells called a callus

Question 20

explain embryo cloning

Answer 20

Embryo cloning:
give fertility hormones to a preferred cow - she produces many eggs
fertilise these with sperm from a preferred bull and once embryos have formed, wash it otut of the uterus
sometimes instead of implanting sperm, eggs are collected and fertilisation occurs in the lab
every cell in the embryo can be planted in a surrogate mother to become a cow –> (it is possible to do this as the cells are still unspecialised)

Question 21

what is adult cell cloning

Answer 21

Adult cell cloning = A whole new animal is produced from the cell of another adult animal

Question 22

what are the main steps to adult cell cloning

Answer 22

Main steps of adult cell cloning:
1. Nucleus is removed from an unfertilised egg
2. at the same time, a nucleus is taken from an adult body cell (e.g. - skin cell)
3. nucleus from adult cell is inserted into an empty egg cell
4. new cell is given a tiny electric shock –> this stimulates it to start dividing to form embryo cells which contain the same genetic info as adult
5. once embryo has developed into a ball of cells, it’s inserted into an adult female’s womb to continue development

Question 23

what two ways can an animal be cloned by

Answer 23

an animal can be cloned by either : 1. dividing an embryo OR 2. cloning an adult cell

Question 24

name an use of adult cell cloning

Answer 24

this method is useful to preserve endangered species

Question 25

what is the problem with trying to use adult cell cloning to save an endangered species

Answer 25

Problem with this: In a natural population one or two can survive change, however with a cloned population, this is doubtful

Question 26

name 4 Advantages of genetic engineering in agriculture:

Answer 26

Advantages of genetic engineering in agriculture:
1. improved growth rates of plants and animals
2. increased food value of crops –> GM crops have much bigger yields than ordinary crops
3. crops can be designed to grow in dry, hot and cold parts of the world
4. crops can make their own pesticide, or are resistant to herbicides used to control weeds

Question 27

name 2 Concerns of genetic engineering in agriculture

Answer 27

Concerns:
1. effects of eating GM foods
2. genes from GM plants and animals may spread to wildlife in the countryside

Question 28

what is a potential benefitc of genetic engineering

Answer 28

a potential benefit of genetic engineering is curing inherited diseases in embryos by putting healthy genes into infected cells