Reproduction

What is asexual reproduction

The formation of new individuals from the cell(s) of a single parent

What is sexual reproduction

The formation of new individuals from the cell(s) of two individual organisms- male and female

What are the advantages of asexual reproduction

Produces large numbers of offsprings very quickly. Only one parent is required so it can be done anytime so saves time and energy. If the parent has good features then all the offsprings will be identical and have the same good features

What are the disadvantages of asexual reproduction

There is no variation as all offsprings look identical to the parents. This is bad because if a disease or new predator comes into their habitat the whole population could be killed. If the parent has any weak features, then all the offsprings will have those features

What are the advantages of sexual reproduction

There is lots of variation because offsprings look different from each parent this means that if the environment changes or diseases and viruses came into the population not all the individuals will die- the stronger ones will survive

What are the disadvantages of sexual reproduction

Since the process requires 2 parents a lot of time and energy is spend in finding the correct partners- this makes it a very slow process

How many chromosomes does each human cell have (except sperm and egg)

46

How many chromosomes does an egg and sperm have

23

What is the function of the scrotum

Bag which holds the testes and keeps the sperms at a low temperature than body

What is the function of the testes

Produces sperms and male hormones

What is the function of the sperm duct/vas deferens

Tube that transfers the sperms from the testes to the urethra

What is the function of the seminal vesicle

Produces fluid that keeps the sperms alive

What is the function of the urethra

Tube through which the semen and urine are removed from the male's body

What is function of the ovary

Produces female hormones and releases an egg every month

What is the function of the uterus

Muscular bag where the embryo develops

What is the function of a vagina

Passage through which the baby isdelivered and place where sperms are deposited during sexual intercourse

How are gametes formed

By Meiosis

What is Meiosis, where does it occur and what is it used for

Occurs in sex organs (ovary and testes). Produces new cells that are different and contain half the number of chromosomes as the original cell. Produces sex cells called gametes-sperm and egg which contain half the chromosome number. This is important so that when the sperm fertilizes the egg the zygote gets the full, correct number of chromosomes of its species

What is mitosis, where does it occur and what is it used for

Produces new cells that are identical and contain same number of chromosomes as the original cell, used for growth and repair. Occurs in body cells

What is the difference between mitosis and meiosis

Meiosis has two rounds of genetic separation and cellular division while mitosis only has one of each. In meiosis homologous chromosomes separate leading to daughter cells that are not genetically identical. In mitosis the daughter cells are identical to the parent as well as to each other

What structure is the placenta

Plate like structure

What does the umbilical cord do?

Joins the foetus to the placenta

What is the function of the placenta

Food and oxygen diffuse in the placenta from the mothers blood to the blood of the foetus. This is then used by the body cells of the foetus to grow and develop new cells which make it grow bigger. Carbon dioxide and waste products diffuse from the blood of the foetus to the mothers blood who then removes the waste with her own wastes.

What goes into the foetus from the mothers blood

Food and oxygen

What goes out to the mothers blood from the foetus

Waste and Carbon Dioxide

What part of the flower is the reproductive organ

The flower

What is the male part of the flower called and what is it made up of

Stamen, made up of anther an filament and pollen

What is the female part of the flower called

Pistil

What is the stigma

Pollen grain lands on this

What is the style

Sperm travels down this

What is the function of the ovary in the flower

Contains the egg where fertilization takes place

What is pollination

Transfer of pollen from the anther to the stigma of the flower

What happens in fertilization

When the pollen lands on the stigma, the pollen releases a sperm nuclei. It travels down the style and fuses with an egg in the ovary of the flower. Sperm nuclei + egg= zygote

What happens to the ovary and the ovules after fertilization

The ovary develops into a fruit. The ovules develop into seeds. The petals, stamen, style and stigma all dry and fall off

What are the 3 ways in which seeds are taken from one place to another

Animals, Water, Wind, Bursting, Humans

What is the first stage of the life cycle of flowering plants

Pollination transfers pollen to stigma

What is the second stage of the life cycle of flowering plants

Fertilization occurs in the ovary to form zygote

What is the third stage of the life cycle of flowering plants

Ovules become seeds and are dispersed, the ovary becomes a fruit

What is the fourth stage of the life cycle of flowering plants

Seeds germinate into new plants

What is the fifth stage of the life cycle of flowering plants

Flower produces male and female gametes

What are chromosomes

Long strands of DNA that are coiled together and contain genetic information.

Where are the chromosomes located

In the nuclei of the cell

What is DNA

Very long molecule that contains the instructions for how every cell should grow

What does the DNA look like

2 strands that are connected by bases which are twisted together like a double helix

What is a gene

A small section of the DNA molecule

What does a gene carry

The genetic code for a particular characteristic, such as eye colour

Dominant allele=

Capital letters

Recessive allele=

Small letters

If the parents give the same dominant allele for a characteristic then the chromosome pair is called

Homozygous dominant

If the parents give the same recessive allele for a characteristic then the chromosome pair is called

Homozygous recessive

If each parent gives different alleles for a characteristic then the chromosome pair is called

Heterozygous

Why can both dark hair parents have blond hair children

The parents are Heterozygous dominant. Since each parents are shaded this means they have dark hair. So each parent has the B allele. The couple have two blond children, blond hair is only possible if two recessive alleles are inherited. This means that each parent must have the recessive allele as well. When the two alleles are put together, this makes the parents heterozygous

Does the mother's blood mix with the blood of the foetus

No, The mother's blood does not mix with the blood of the fetus, but the placenta lets substances pass between the two blood supplies

What is the embryo of a seed

The young root and shoot that will become the adult plant

What is the function of a foodstore in a seed

Starch for the young plant to use until it is able to carry out photosynthesis

What is the function of a seedcoat in a seed

Atough protective outer covering