Human Reproduction & Genetics Flashcards
Ovaries
Ovaries store and release eggs.
Fallopian tubes
The fallopian tubes carry the egg to the uterus, fertilisation occurs here.
Uterus (womb)
The uterus (womb) is where the fertilised egg becomes implanted and finds nourishment.
Cervix
The cervix leads from the vagina to the uterus.
Vagina
The vagina holds the male penis during sexual intercourse.
Ovulation
Ovulation is when an egg is released from the ovary on an average of every 28 days.
The egg is released:
The egg is released on day 13-15 of the menstrual cycle and it passes along the fallopian tubes to the uterus.
Menstruation/Period
The lining and a small amount of blood pass out through the vagina (day 1-5)
Fertile period
These are the days of the menstrual cycle when the woman is most likely to become pregnant.
Menopause
Menopause signals the end of a female’s ability to reproduce and also the end of her menstrual cycle. It happens at different ages for different people, typically in the late 40’s to early 50’s.
Testes
The testes produce sperm.
Scrotum
The scrotum is where the testes are, it is located outside the body to ensure the temperature is lower than body temperature for healthy sperm.
Epididymis
The epididymis is a coiled tube on the outside of each testis that stores sperm and allows them to mature fully.
Vas deferens
The vas deferens (sperm duct) brings the sperm from the testes to the penis.
Seminal vesicles, prostate gland and Cowper’s gland
The seminal vesicles, prostate gland and Cowper’s gland produce seminal fluid which mixes with sperm to form semen, it nourishes the sperm and allows them to swim.
Penis
The penis enters the female and ejaculates semen.
Puberty
Puberty describes when the body starts becoming sexually mature (reproductive organs develop). It normally happens between the ages 10 and 16.
Male puberty
In males, sex hormones (testosterone) are released causing the voice to deepen, hair grows around sex organs, face, chest and underarms, the testes and penis grow bigger and start to produce sperm.
Female puberty
In females when the sex hormones (oestrogen and progesterone) are released the breasts develop, hips widen, and hair begins to grow on the body.
During intercourse the man’s
During intercourse the man’s penis fills with blood and becomes hard enough to be placed inside the woman’s vagina.
Semen
A mixture of sperm cells and seminal fluid is released into the vagina during intercourse.
The sperm swim
The sperm swim up the uterus and into the fallopian tubes.
Fertilisation
If an egg is present in the fallopian tube, and a couple have sexual intercourse, then one of the sperm cells may fuse with it.
Fertilised egg
The nuclei of the sperm and egg fuse together. The woman is now pregnant.
Zygote —> Embryo —> Foetus
-Zygote: Cell division occurs and growth.
-Embryo: which attaches to the lining of the uterus (implantation) grows more, and after 8 weeks it will look like a human.
-Foetus
Implantation
When the embryo attaches to the lining of the uterus, the uterus lining does not break down so menstruation stops during pregnancy.
Length of pregnancy
The average length of a human pregnancy is 40 weeks.
Amniotic fluid
As the embryo develops in the uterus, it is protected inside a bag of fluid. This fluid provides a cushion for the embryo.
Umbilical cord
A tube joining the embryo to the placenta.
Placenta
-The placenta is rich in blood vessels
-It is here at the placenta that food and oxygen from the mother’s blood pass into the baby’s blood
-Also wastes such as carbon dioxide pass from the baby’s blood into the mother’s
Labour
The birth of a baby begins when the uterus muscles start to contract.
Lactation
The production of breast milk.
Colostrum
The first three days of milk – very nutritious, and helps protect the baby from infection.
Family planning
To control the number of children you have, you need to control the number of times fertilisation takes place.
Natural methods of contraception
Natural methods of contraception aim to detect the day ovulation takes place and avoid intercourse during the fertile period.
Artificial methods of contraception
prevent the sperm and egg meeting.
Condom
prevents sperm entering the vagina.
contraceptive pill
which prevents ovulation
reliability of contraception
It is important to realise no method is 100% reliable.
Genetics
Genetics is the study of the inheritance of characteristics.
Inheritable characteristics
Many physical characteristics such as eye color and shape of ears were inherited from your parents.
Chromosomes & Genes
Chromosomes: The nucleus of each sex cell (gamete) contains 23 thread-like structures called chromosomes.
Chromosomes are made of
Chromosomes are made of protein + DNA. These chromosomes carry genes.
Genes
Genes are chemicals found on chromosomes that pass on information from parents to children.
DNA
Deoxyribonucleic acid
46 chromosomes
When an egg and sperm cell fuse (each has 23 chromosomes) they give the individual they are creating 46 chromosomes.
Homozygous
having two identical alleles of a particular gene or genes.
Heterozygous
having two different alleles of a particular gene or genes.
Dominant
Dominant refers to the relationship between two versions of a gene.
Recessive
Recessive inheritance means both genes in a pair must be abnormal to cause disease.
Biodiversity
There are many different types of living things.
Fossils
The remains of very ancient living things.
Extinct
Some living things disappear.
Natural selection
How the variety of living things may have arisen, the most widely accepted explanation based on evidence is the theory of evolution by natural selection.
Species
A group of living things that can reproduce together to produce offspring which themselves can reproduce.
Mutation
A change in a gene.
Evolution
The process by which different kinds of living things develop from earlier forms by genetic changes over long periods of time.
Adaptation
A characteristic that helps an organism to survive and reproduce.
