B2.5 Simple Inheritance In Animals And Plants Flashcards
Chromosome, DNA, nucleus, cell, base, gene
Put these in order from smallest to biggest
Smallest ------- Base Gene DNA Chromosome Nucleus Cell ------- Biggest
How many pairs of chromosomes does each cell have?
23 pairs
Define chromosome
Long section of DNA containing many genes and the instructions for lots of different characteristics
Define a gene
A small section of DNA containing the instructions for a single characteristic
What part of a cell contains the genetic material
The nucleus
What happens during mitosis?
Chromosomes copy each other and make a replicated strand. Spindle fibres are formed and you get each type of chromosome then they pull apart making two cells identical to the first
What are the female and male gametes called and where are they made?
Eggs/ova in the ovaries
Sperm in the testes
What happens during meiosis?
The chromosomes are copied, the cell divides into two and these new cells immediately divide again. This gives four sex cells each with a single set of chromosomes.
Does mitosis or meiosis give variety? And why is there variety?
Meiosis because in each sex cell they contain random mixtures of the original chromosome pairs
What happens during fertilisation?
Two sex cells join during fertilisation and the single cell formed has a full set of chromosomes (23 pairs-half sperm and half egg). The combination of genes on the chromosomes of every newly fertilised ovum is unique.
Asexual reproduction produces offspring as a result of ________
Sexual reproduction produces offspring as a result of ________
Mitosis
Meiosis
Define pluripotent
Embryo stem cell can become lots of things
What can stem cells become?
Nerve cells
Red blood cells
Muscle cells
Tissue cells
What are the pros of embryo stem cells?
Easy to collect and produce in a lab or embryos can be donated by IVF patients who don’t want them
People don’t need an operation to get them
Stem cells can turn into any cells
What are the cons of embryo stem cells?
Expensive
Embryo is destroyed which is a living thing - unethical