Reproduction Flashcards
What is mitosis?
Mitosis is when a cell reproduces itself by splitting to form two cells with identical sets of chromosomes.
What is mitosis also used for?
It is how all plants and animals grow and repair damaged tissues. Cloning also involves mitosis.
What is sexual reproduction?
Sexual reproduction involves the fusion of male and female gametes. Because there are TWO parents! the offspring contain a mixture of their parents genes.
What are the four stages of the menstrual cycle?
STAGE 1: day one is when bleeding starts. The uterus lining breaks down for about four days.
STAGE 2: the uterus lining builds up again,From day 4-14, into a thick spongy layer full of blood vessels, ready to receive a fertilised ovum (egg)
STAGE 3: an ovum develops and is released from the ovary at day 14.
STAGE 4: the wall is then maintained for about 14 days until day 28. If no fertilised ovum has landed on the uterus wall by day 28, the spongy lining starts to break down and the whole cycle starts again.
How is oestrogen involved in the menstrual cycle?
- causes the lining of the uterus to thicken and grow.
- stimulates the release of an ovum by day 14.
How is progesterone involved in the menstrual cycle?
-maintains the lining of the uterus. When the level of progesterone falls, the lining breaks down.
What is the theory of evolution?
Life began as simple organisms from which more complex organisms evolved (rather than just popping into existence.)
What are mutations?
Mutations are changes to the genetic code. Mutation is rare,mrajdom change in an organisms DNA that can be
What is asexual reproduction?
Asexual production involves only one parent. The offspring have identical genes to the parent- so there’s no variation between parent and offspring.
