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Biology (Y9) Flashcards

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Biology 101 flashcards
1
Q

What is a variation?

A

The presence of differences between living things of the same species is called variation.

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2
Q

Different types of variations?

A

Genectic and Environmental

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3
Q

Examples of genetic variation

A

Eye colour
Blood type

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4
Q

Examples of environmental variations

A

Beard
Moustache

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5
Q

Examples of both genetic and environmental variation

A

Short sighted
Hair colour
IQ
Height
Baldness
Weight
Skin colour
shoe size

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6
Q

What is genetic variation?

A

Genetic variation is the differences in DNA sequences between individuals within a population. Variation occurs in germ cells i.e sperm and egg,and also in somatic (all other) cells.

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7
Q

Defenition of a Gene

A

A gene is a section of DNA that codes for a certain type of characteristic

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8
Q

What are alleles?

A

They are different forms of the same gene that code for different versions of a characteristic

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9
Q

What is a Homozygous allele?

A

They are the same ( BB,dd,EE)

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10
Q

What is a heterozygous allele?

A

Different allele (Bb,Ee)

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11
Q

What is a dominant allele?

A

It only requires 1 dominant allele for the characteristic to be expressed in the organism. (1 parent brown eyes + 1 parent blue eyes = offspring will have brown eyes) (Always capital letter-EE,Ed)

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12
Q

What is a recessive allele?

A

A allele that requires 2 copies of a recessive characteristic to be expressed in the organism. (Always in lowercase-ee,De)

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13
Q

Explain about chromosomes?

A

The structure is found inside the nuclues of a cell. A chromosome is made up of protiens and organized into genes. In humans,each cell normally has 23 pairs of chromosomes, for a total of 46. 22 of these pairs are called autosomes,they look the same in both male and female. You inherit 23 chromosomes from each parent.

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14
Q

2 ways of reproduction? And what are they?

A

Asexually= Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. Only requires 1 parent.

Sexually=by 2 different sex cells or gametes coming together.

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15
Q

What does DNA stand for and what is it?

A

Deoxyribonucleic acid is a polymer composed of 2 polynucleotide chains which coil around one an other to form a double helix. DNA is found in the Nuclues and Mitrochondria of a cell. The structure of DNA was discovered by 3 scientists (Francis crick,Rosalind Franklin and James watson.

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16
Q

What are genetic crosses?

A

The deliberate breeding of two different indiviuals that result in offsprng that carry part of the genetic material of each parent

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17
Q

What are gametes?

A

They are sex cells (egg,sperm)

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18
Q

What are phenotypes?

A

Phenotypes are the set of observable characteristics or traits of an organism.

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19
Q

What are genotypes?

A

The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location.

20
Q

What are genetic crosses?

A

The delibarate breeding of 2 different indiviuals that results in offspring that carry part of the genetic material of each parent.

21
Q

What is the phenotype?

A

The physical expression of the allele pair/genotype.

22
Q

What is the genotype?

A

The allele pair of each characteristic. A persons genotype is their unique sequence of DNA.

23
Q

What are gametes?

A

Gametes are the reproductive cell of an animal or plant (sex cell)

24
Q

What are genetic disorders?

A

Genetic disorders are conditions passed on from parents to their offspring in their genes. Some examples may include cystic fibrosis and polydactyl.

25
Q

What is cystic fibrosis?

A

Cystic fibrosis is a gentic disorder which is when lots of sticky mucus blocks the air passages,making it difficult to breath and can lead to chest infections. It is a disorder caused by a recessive allele (meaning you need 2 copies of the recessive allele to have the disorder.

26
Q

What does it mean to be a carrier?

A

It means to carry a copy of the allele, but do not have the disorder.

27
Q

What is polydactyl?

A

It is a disorder that results in a child being born with extra fingers or toes. It is caused by a dominant allele. Therefore if in your genes you contain the dominant allele you will have the disorder. You cannot be a carry of this disorder.

28
Q

What is a clone?

A

A clone is an organism that is genetically identical to its parent. This means that it has the same genes as its parent, and will therefore look identical.

29
Q

Explain how a clone of bacteria is produced? (Cell division e.c.t)

A

When bacteria reproduce,they divide in half. Each half contains identical genes, resluting in 2 identical organisms,called clones. New organisms are created by cell division.

30
Q

How are clones produced?

A

They are produced asexually (only requires 1 parent)

31
Q

What are characteristics?

A

A feature of an organism.

32
Q

What is dolly the sheep?

A

A sheep and an example of a clone.

33
Q

What is a gene pool?

A

The vareity of genes avalible in a population.

34
Q

What is cutting?

A

A small section of a plant is taken and planted

35
Q

What is selective breeding?

A

Selective breeding is when animals with disirable characteristics are breed producing offspring with disired characteristics. They are bred with more animals with desired characteristics (this process is repeated).

36
Q

Example of selective breeding and why?

A

Farmers may selectively breed dairy cattle that produce lots of milk Or strawberry plants that produce large strawberrys. When producing offspring farmers will choose their best plants or animaks to breed.

37
Q

What are the stages of selective breeding?

A

1) choose 2 parents with the desired characteristics
2)breed them together
3)choose offspring that show the desired characteristics and breed them
4)Repeat over many generations

38
Q

What are some advantages of selective breeding?

A

-incresed milk/meat yield from cattle (which may increase profits for farmers
-disease resistance in food crops or garden plants
-can produce domesticated animals with a gentle nature (e.g pug/labradoodle)

39
Q

What are some disavantages of selective breeding?

A

-selective breeding can lead to inbreeding.
- because of the smaller genetic pool slective bred organisms are more likely to pass on harmful resesive allele
-they are more likely to be suceptible to diseases

40
Q

What is ‘inbreeding’?

A

It is the mating of organisms closely related by ancestry.

41
Q

What are some advantages of cloning?

A

-can produce lots of offspring with desirable characteristics
-study of clones could help treat/cure certain diseases
-could help bring back endangered or extinct species

42
Q

What are some disavantages?

A

-increase in birth size and a variety of defects in vital organs
-There isnt a 100% chance that it will be sucessful
-There is no genetic variation

43
Q

What is natural and artificail cloning?

A

Natural cloning in animals=identical twins
Atificial cloning in animals=dolly the sheep (1996)

44
Q

What is genetic engineering? (Add example)

A

Scientists are now able to altar an organisms genes to produce an organism with a desirable characteristic. For example, crops can be produced so that they are resistant to disease. This is called genetic engineering (or genetic modification)

45
Q

What are the stages of genetic engineering?

A

1)select the desired characteristic
2)isolate the gene responsible for the characteristic using emzymes
3)insert this gene into another organism
4)replication of the organism

46
Q

What are some advantages of genetic engineering ?

A

-improving crop yield
-improving resistance to pesticides
-manufacturing a certain chemical
-extend shelf-life of fruit and veg

47
Q

What are some disavantages of genetic engineering?

A

-inserted genes may have unwanted side affects
-possible harm when GM crops are eaten by humans/animals
-damage to the food chain

Science (4 decks)

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