Topic 3 - Genetics Flashcards
What are gametes?
Examples of gamete’s ?
Gametws are reproductive cells.
Sperm and egg cells
How many chromosomes does a human cell nucleus contain?
46
What’s the diploid number for a human ?
46
What’s the haploid number for a human?
23
Are gametes diploid are haploid?
Gametes are haploid
What does the male gamete fuse with to produce a zygote?
A male gamete guess with the female gamete to produce a fertilised egg. (Zygote)
What’s a zygote?
A zygote is a fertilised egg
What happens to the zygote for it to become an embryo?
The zygote undergoes cell division by mitosis to become an embryo
How is mitosis differnt to meiosis?
Mitosis produced identical cells however meiosis produces unidentical cells
What is the result of meiosis?
At the end of meiosis, you get four haploid cells, these are the gametes. They are all genetically differnt
What does meiosis produce and where does it happen?
Meiosis produces gametes and it happens in the reproductive organs (ovaries and testies)
What are the two types of reproduction?
Sexual
Asexual
In which type of reproduction is mitosis used in? Which one is meiosis used in
Asexual- mitosis
Sexual- meiosis
Advantages and disadvantages of asexual reproduction…
Advantages- produce offspring quickly because reproductive cycle is fast. Only one parent is needed.
Disadvantages- no genetic variation between offspring. Whoel poopulafion could be affected by something.
Advantages and disadvantages of sexual reproduction?
Advantages- sexual reproduction creates genetic variation within the population. This means if the environment changes, some of population will survive.
Disadvantages- takes more time and energy than asexual reproduction. Two parents are needed
Is a dna strand a polymer or a monomer?
What are DNA strands made up of?
DNA strands are polymers made op of many repeating units called nucleotides.
What is each nucleotide on DNA made up of?
A sugar
A phosphate
A base
What forms the backbone in a dna strand?
The sugar and phosphate
What are the 4 bases in dna?
A,T
C,G
What is the shape of DNA ?
A double helix
What are the complementary base pairs joined together by?
Complementary base pairs are joined together by weak hydrogen bonds.
What are chromosomes and where are they found?
-Chromosomes are long, coiled up molecules of DNA.
- chromosomes are found in the nucleus of eukaryotic cells
What is a gene?
A gene is a section of DNA on a chromosome that codes for a particular protein/ trait
Practical for extracting DNA from a fruit cell. What will the detergent do? What does the salt do?
What will happen at the end?
1) mash strawberry and putting them in a beaker containing a solution of dergent and salt. Mix it.
- the detergent will break down cell membranes to release DNA.
- the salt will make the DNA stick together
2) filter the mixture to get the froth and big, insoluble bits of cell out.
3) gently add ice cold alcohol to the filtered mixture.
4)the DNA will start to come out the solution as it’s not soluble in cold alcohol. It will appear as stringy white precipitate.
What is protein synthesis?
The production of proteins
What are proteins made up of?
Proteins are made up of Amino acids
Why do amino acid chains fold up?
To give each protein a different shape, therefore a different function
What decides the order of amino acids in a protein?
The order of bases in a gene decided the order of amino acids in a protein
What’s each amino acid coded for by?
A sequence of 3 bases on a gene, this is called a base triplet