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Flashcards in Genetics Deck (42)
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1
Q

Define Sexual reproduction

A

Genetic Infomation

2
Q

How is meiosis different to mitosis.

A

It doesn’t produce identical cells

3
Q

How many divisions are involved in meiosis?

A

2

4
Q

How many daughter cells are produced by meiosis?

A

4

5
Q

How many bases are there in DNA?

A

4

6
Q

What are the names of the bases in the DNA?

A

Adenine, thymine, cytosine and guanine

7
Q

Name the 2 complementary base pairings.

A

A with T, C with G

8
Q

What are the complementary base pairings joined together with?

A

Weak Hydrogen Bonds

9
Q

Define a Chromosome

A

Long coiled up molecules of DNA found the nucleus of eukaryotic cells.

10
Q

Define a Gene.

A

A section of DNA that codes for a particular protein.

11
Q

What is an organism’s genome

A

All of an organism’s DNA.

12
Q

Why do you use detergent when extracting DNA from cells?

A

It breaks down the cell membranes to release the DNA.

13
Q

Why do you use salt when extracting DNA from cells?

A

It makes the DNA stick together.

14
Q

Where does DNA transcription take place?

A

The Nucleus

15
Q

Briefly describe how transcription happens.

A

1) RNA polymerase binds to a region of non-coding DNA in front of a gene.
2) The 2 DNA strands unzip and the RNA polymerase moves along one of the strands of DNA.
3) It uses the coding DNA in the gene as a template to make the mRNA. Base pairing makes sure each is complementary to each other.
4) The mRNA molecule moves out of the nucleus into the cytoplasm.

16
Q

Which base become Uracil in the mRNA?

A

Thymine

17
Q

Where does DNA translation take place?

A

In the ribosomes

18
Q

Briefly describe how translation happens?

A

1) Amino Acids are brought to the ribosome by tRNA
2) The order in which the amino acids are brought to the ribosome matches the order of the base triplets in the mRNA. These are known as codons.
3) The anticodon is complementary to the codon for the amino acids.
4) The amino acids are joined together by the ribosome. This makes a polypeptide molecule.

19
Q

What did Mendel do with pea plants?

A

Crossed 2 pea pants of different heights then bred 2 of the offspring to find that there was a 25% chance of a pea plant in this generation to be small.

20
Q

What 3 important conclusions did Mendel reach?

A

1) Characteristics in plants are determined by ‘hereditary units’
2) Hereditary units are passed on to offspring from both parents, one from each
3) Hereditary units can be recessive or dominant.

21
Q

What do we now call Mendel’s ‘hereditary units’?

A

Genes

22
Q

Why were Mendel’s experiments not recognised at the time?

A

Lack of prior knowledge of DNA, genes and chromosomes

23
Q

What is an allele?

A

A different version of the same gene

24
Q

Give an Example of a homozygous and heterozygous pair.

A

Homo- GG, gg, KK, kk etc

Hetro- Tt, Rr, Gg, Vv, Hh

25
Q

What is your phenotype?

A

The combination of alleles that you have and therefore your characteristics.

26
Q

Create a Punnett Square for 2 heterozygous parents. What is the chance that a child will carry the disease?

A

B b 50% chance of being a carrier
B BB Bb
b Bb bb

27
Q

Create a Punnett Square in order to determine sex.

A

X X
X XX XX
Y XY XY

28
Q

Which chromosome is sex determined on?

A

23rd

29
Q

Why do sex linked genetic disorders exist?

A

They only exist on X chromosome. They are recessive so Females (XX) need both to have the disease. Males (XY) only need one on the X to have the disease.

30
Q

Give 2 examples of sex-linked genetic diseases.

A

Colour Blindness and Haemophilia.

31
Q

How many alleles are there for blood group?

A

3 Io, Ia and Ib

32
Q

Which alleles for blood group are co-dominant and which are recessive

A

Ia and Ib co-0dominant

Io recessive

33
Q

What is a mutation?

A

Changes to the base sequence of DNA

34
Q

Why do most mutations have no effect on the phenotype?

A

Because the mutation doesn’t cause a different protein to be made.

35
Q

Give 1 example of a environmental factor and 1 off a genetic factor that effects height

A

Genetic- parents alleles

Environment- Amount of Food

36
Q

How many genes did the Human Genome Project map?

A

20500.

37
Q

Give 3 Medical Applications for the Human Genome Project.

A

Prediction and Prevention of disease
Testing and treatment for inherited disorders
New and Better medicines

38
Q

Give 2 drawbacks of the Human Genome Project.

A

Increased stress, Gene-ism and Discrimination by employers and insures

39
Q

Give 2 advantages to asexual reproduction

A

Very quick, Only 1 parent is needed

40
Q

Give 1 disadvantage to asexual reproduction

A

No genetic variation

41
Q

Give 1 advantage to sexual reproduction

A

Creates Genetic Variation

42
Q

Give 2 disadvantages to sexual reproduction

A

Takes time and energy, 2 parents are needed