DNA and meiosis Flashcards
What is asexual reproduction?
Reproduction involving only one adult cloning themselves (e.g. bacteria and some plants)
What is sexual reproduction?
Reproduction involving two adults
What are the advantages of asexual reproduction?
Do not need to find a mate, faster reproductive cycle
What are the disadvantages of asexual reproduction?
No variation in the population, meaning they are more susceptible to disease
Which process is involved in asexual reproduction?
mitosis
What are the advantages of sexual reproduction?
variation in the population, species can adapt to new environments and is less susceptible to disease
What are the disadvantages of sexual reproduction?
slower than asexual, need to find a mate which takes time and energy. Some individuals may not find a mate
Which process is involved in sexual reproduction?
Meiosis (and fertilization)
Which types of cell are produced by meoisis?
Gametes (sperm and egg in humans)
How many cells are produced during meiosis?
4
How many times does a cell divide during meiosis?
twice
Are the daughter cells produced by meiosis genetically different or genetically the same?
different
What is the shape of DNA called?
Double helix
which type of bonds hold the base pairs together in DNA?
Hydrogen bonds
What is DNA made from
sugar, phosphate and nucleotide bases
What are the 4 types of nucleotide base present in DNA?
Adenine (A), Thymine (T), Cytosine (C) and Guanine (G)
Which nucleotide base pairs with which?
A with T, C with G
What is a gene?
A section of DNA which codes for a specific protein
What is a genome?
All the DNA of an organism
What is a haploid cell?
A cell with half the usual number of chromosomes (e.g. gametes)
What is a diploid cell?
A cell with the usual number of chromosomes
Are the cells produced by meiosis haploid or diploid?
haploid
How many chromosomes are in a human body cell?
46 (23 pairs)
How many chromosomes are in a human sperm cell?
23
When extracting DNA from fruit, why does the fruit need to be mashed first?
To break down cell walls
When extracting DNA from fruit, why is either an enzyme or washing up liquid added?
To break down the cell membrane and the nuclear membrane
When extracting DNA from fruit, why does the mixture need to be filtered?
To remove insoluble substances so the DNA can be seen
When extracting DNA from fruit, which chemical is used to precipitate the DNA?
ethanol
What is a change in the sequence of bases in DNA called?
Mutation
What was the purpose of the human genome project?
Sequence all the DNA in the human body, in order to have greater understanding of the function of many genes, and to offer treatments for genetic diseases
