Reproduction Flashcards
What is the purpose of reproduction?
The purpose of reproduction is to ensure that individuals produce offspring so that the species can survive.
When does puberty start?
Puberty starts between the ages of 10 and 12 when the pituitary gland in the brain starts secreting hormones into the blood of boys and girls.
What hormone do the testes secrete?
The testes secretes testosterone.
What are the different secondary sexual characteristics in boys?
Deepening voice
Facial hair
Under arm hair
Pubic hair
Growth spurt
What hormone do the ovaries secrete?
The ovaries secrete oestrogen.
What are the different secondary sexual characteristics in girls?
Growth spurt
Breast formation
Widening of hips
Pubic hair growth
Under arm hair growth
What do the hormones secreted by the pituitary gland also do in boys and girls?
In girls, the hormones secreted by the pituitary gland also start the process of ovulation - the release of an ovum from the ovary once a month.
In boys, the hormones secreted by the pituitary gland also cause the testes to start producing sperm cells.
What is asexual reproduction?
Asexual reproduction occurs in unicellular organisms when they undergo cell division - called binary fission.
Asexual reproduction occurs in most micro-organisms for example bacteria.
Asexual reproduction does not require male and female sex cells.
What is sexual reproduction?
Sexual reproduction requires sex organs that produce male and female sex cells.
In humans (mammals) the sex organs are ovaries in females and testes in males where sex cells are produced.
What is fertilisation?
Fertilisation is when male and female sex cells fuse together to form a single zygote cell.
What is a zygote cell?
A zygote cell is the cell formed immediately after fertilisation.
What is an embryo?
An embryo is a ball of identical cells formed when the zygote cell undergoes cell division.
What is a foetus?
A foetus is formed when the embryo develops features that look like a human being.
What is the nervous coordination system?
The nervous coordination system consists of a network of nerves that carry electrical nerve impulses that control muscle contraction and therefore coordinate body movement.
What is the chemical coordination system?
The chemical coordination system consists of ductless endocrine glands that secrete hormones into the bloodstream. The blood carries the hormones to a target organ where the hormones either have an inhibiting or stimulating effect.
What body system does the chemical coordination system control?
The chemical coordination system controls the reproductive system.
What is a sperm cell made up of?
A head, an acrosome, a middle piece, a nucleus and a tail.