B1 6.1 to B1 6.7

HideShow resource information
  • Created by: ja7sa096
  • Created on: 24-04-16 10:08
Why do we resemble our parents?
Because parents pass on their genetic information to their offspring in gametes (the sex cells)
1 of 31
What are inside the nucleus?
2 of 31
What are the chromosomes made up of?
DNA (deoxyribonucleic acid)
3 of 31
What is DNA?
Long molecule in a double helix, made of 4 bases: A C G T, where genetic information is stored
4 of 31
What is a gene?
A section of a chromosome, sequence of the 4 bases
5 of 31
How many pairs of chromosomes does each human cell have?
6 of 31
What do genes do?
Control what an organism is like and the development of different characteristics, instructions for making proteins, units of inheritance
7 of 31
What is asexual reproduction?
Involves only one parent, no joining of special sex cells, no variety in offspring- genetically identical to parent, binary fission, clones
8 of 31
What are clones?
The genteically identical offspring of asexual reproduction
9 of 31
What is sexual reproduction?
Two parents give rise to offspring, each passes on half its genes, offspring have unique combination of genes, variation
10 of 31
What is variation?
Difference in the characteristics of an organism
11 of 31
What causes variation?
Genetic differences, environmental influences
12 of 31
What does variation ensure?
A population that can survive
13 of 31
When the gametes fuse what is formed?
A zygote
14 of 31
Give examples of some features genes decide.
Curved/straight thumb, attached/unattached earlobe, dimples/no dimples, eye colour
15 of 31
Why do we clone plants?
Cloning allows growers to mass produce plants that may be difficult to grow from seed. All the plants are genetically identical, which is useful because you can be sure of their characteristics
16 of 31
How do we clone plants?
Cuttings, tissue culture
17 of 31
How do cuttings work?
Remove small piece of old plant, keep in the right conditions, it will grow to form new plant, hormone rooting powders encourage to grow
18 of 31
How does tissue culture work?
Small amounts of parent tissue taken, plant material transferred to agar jelly with nutrients, plant hormones added so cell divides, cells grow rapidly into small plats and tissues, more hormone added, plant develops
19 of 31
Why do we clone animals?
Medicinal purposes, reviving endangered/extinct species, reproducing a deceased pet, cloning livestock, drug production, cloning organs, child for an infertile couple, child who is dying of terminal illness
20 of 31
What are the two ways in which we can clone animals?
Embryo transplants and adult cell cloning
21 of 31
How do embryo transplants work?
Sperm and egg is taken from best bull and cow and are fertilised, fertilised egg divides to form embryo containing many cells, embryo is separated to from individual cells and new embryos with same genes, embryos implanted in surrogate mother, born
22 of 31
How does adult cell cloning work?
Nucleus removed from an adult body cell, unfertilised egg cell is enucleiated, nucleus inserted into egg cell, electric shock causes egg to divide to form embryo cells, inserted into womb of an adult female, born same genes as adult skin cell
23 of 31
What are the advantages of embryo transplants?
Quicker, easier, cheaper
24 of 31
What are the disadvantages of embryo transplants?
All susceptible to same diseases, reduces gene pool so they cannot adapt
25 of 31
What are the advantages of adult cell cloning?
Genetically identical, no variation, guaranteed desired features
26 of 31
What are the disadvantages of adult cell cloning?
Expensive, difficult, unreliable
27 of 31
What is genetic engineering?
The process by which genes can be transferred to the cells of animals and plants at an early stage of their development so they develop desired characteristics
28 of 31
How can we genetically engineer bacteria to produce human insulin?
Extract the DNA from some human cells, use a restriction enzyme to cut out insulin gene, use the same enzyme to cut bacteria DNA plasmid, use a different enzyme to stick human insulin gene in bacteria plasmid, plasmid holding insulin put in bacteria
29 of 31
What are the advantages of genetic engineering?
Can make exact proteins we need in exact amounts needed in a pure form, improve growth rates of plants/animals, bigger yields, solve world hunger, create pesticides, resistant to herbicides
30 of 31
What are the disadvantages of genetic engineering?
Consumers are wary of GM foods, GM genes may escape into natural ecosystems, GM crops are often made infertile so farmers need to buy new seeds annually, long term effect unknown, designer babies, not natural, religion
31 of 31

Other cards in this set

Card 2


What are inside the nucleus?



Card 3


What are the chromosomes made up of?


Preview of the front of card 3

Card 4


What is DNA?


Preview of the front of card 4

Card 5


What is a gene?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all DNA and inheritance resources »