Combined AQA biology paper 2 - AQA

What is homeostasis ?

keeping conditions inside your body.

What does the control system ?

keeps the conditions in your body steady.

What happens in the blood glucose level is too high ?

the control system decreases the level.

What happens in the blood glucose level is too low ?

the control system increases the level.

What does the nervous system mean ?

that humans react to their surroundings and coordinate their behaviour.

What does the Central Nervous System (CNS) consist of ?

brain and spinal cord.

What is the CNS connected to ?

the body by sensory neurones and motor neutrons.

What is are Sensory Neurones ?

These carry information as electrical impulses from the receptor to the CNS.

What are Motor Neutrons ?

These carry electrical impulses from the CNS to effectors.

What are Receptors ?

Cells that detect stimuli.

Examples of Receptors ?

Receptor in the ear detect sound.

What does Effectors responded to ?

Electrical impulses and bring about to a change.

Examples of Effectors ?

Muscles and glands.

What is the process of CNS ?

Stimulus - Receptor - Sensory Neurone - CNS - Motor Neurone - Effector - Response.

What is a Synapses ?

Is where two neurones join together.

What are Reflexes ?

an automatic responses to prevent injury.

What are hormones ?

Are chemical messengers sent in the blood.

What is another name for the Pituitary Gland

Master Gland.

What does the Pituitary Gland produce ?

many hormones that regulate body conditions.

What do Ovaries produce ?

oestrogen.

What is oestrogen involved in ?

Menstrual cycle.

What do Testes produce ?

testosterone.

What do Testes control ?

puberty and sperm production in males.

What does Thyroid produce ?

Thyroxine

What is Thyroxine involved in ?

Rate of metabolism , heart rate and temperature

What does the Adrenal Gland produce

Adrenaline

What is Adrenaline involved in ?

Prepare the body for a 'fight or flight ' response

What does the Pancreas produce ?

Insulin.

What is Insulin used in ?

Regulate the blood glucose level.

• Very FAST action.

• Act for SHORT TIME.

Characteristics of Nerves ?

• Act on a very PRECISE AREA.

• SLOWER action.

• Act for a LONG TIME.

Characteristics of Hormones ?

• Act in a more GENERAL way.

What does Insulin used for ?

Reducing blood glucose levels.

How many types of diabetes are there ?

2

What is type 1 diabetes ?

where pancreas produces little or no insulin.

How do you treat Diabetes type 1 ?

Need injections of insulin throughout the day.

What is type 2 diabetes ?

where a person becomes resistant to their own insulin this can be influences by lifestyle choices.

How do you treat Diabetes type 2?

eating a carbohydrate -controlled diet and controlled regular exercise.

How many different stages are there in a Menstrual Cycle ?

4 stages.

What is stage one of the Menstrual Cycle ?

When menstruation (blending) starts, uterus lining breaks down for about 4 days.

What is stage two of the Menstrual Cycle ?

The uterus lining builds up again from day 4-14.

What is stage three of the Menstrual Cycle ?

An egg develops and is released from ovary at day 14. This is called ovulation

What is stage four of the Menstrual Cycle ?

The wall is then maintained (kept the same) for about 14 days until day 28.

What happens to an un fertilised egg ?

The uterus wall by day 28 , the spongy lining starts to break down. The whole cycle starts again.

• FSH ( Follicle-Stimulating Hormones )

• LH ( Luteinsing Hormone )

• Oestrogen

The Menstrual Cycle is controlled by 4 hormones which are?

• Progesterone

FSH ( Follicle-Stimulating Hormones ) what does this hormone do ?

Causes an egg to mature in one of the ovaries.

LH ( Luteinsing Hormone ) what does this hormone do ?

Causes the release of an egg (ovulation)

Oestrogen & Progesterone what does these hormone do ?

Are involved in the growth and maintenance of the uterus lining.

What is definition of Fertility ?

How easy it is for a woman to get pregnant.

What is definition of Contraceptives ?

Things that prevent pregnancy.

How can Hormones be used to prevent pregnancy?

Used in contraceptive ( hormonal contraceptives)

What is Oral contraceptive ?

a pill that stops the hormone FSH from being released this stops eggs maturing. 99% effective. Can cause headaches and feeling sick.

• Contraceptive patch.

• Contraceptive implant.

Examples of Hormonal contraceptives ?

• Contraceptive injection.

What is a Contraceptive patch ?

A small patch that is stuck to the skin this slowly releases Progesterone (stops egg from maturing) , it lasts one week.

What is a Contraceptive implant ?

inserted under the skin of the arm this slowly releases Progesterone (stops egg from maturing) , can last for 3 years.

What is a Contraceptive injection ?

An injection this slowly releases Progesterone (stops egg from maturing) ,that can last 2/3 months.

What is an Intrauterine device (IUD) ?

An T-shaped device thats inserted into the uterus, this can stop fertilised eggs from implanting in the uterus wall.

Examples of non- hormonal contraceptives ?

Condom or Diaphragm.

What does a Diaphragm do ?

A shallow plastic cup that fits over the entrance to the uterus, this must be used with spermicide to allow the sperm to killed or disabled.

What does a Condom do ?

Worn over penis during sexual intercourse ( males) , worn inside the vagina ( woman). Protect against sexually transmitted diseases.

What are the other ways of avoiding pregnancy ?

Sterilisation , Naturel methods and Abstinence.

What is Sterilisation ?

involves cutting or tying the fallopian tubes (woman) , cutting or tying the sperm duct (males) , this is permeant (last for life).

What is an Naturel methods ?

Not having sexual intercourse when a woman is at the stages of the menstrual cycle she is like to get pregnant , but not very effective.

What is Abstinence ?

The only way to be sure that sperm and egg don't meet is to not have have intercourse , this is called Abstinence.

What are Chromosomes ?

Long molecules of DNA.

What is DNA ?

chemical that all genetic material in a cell is made up from.

What is it called when two strands of DNA are coiled together ?

Double Helix.

What is an DNA strand called ?

Polymer that is made up of lots of smaller pieces joined together.

What are genes ?

Small sections of DNA found on a chromosomes.

What do genes codes do ?

are part of a particular sequence of amino acid, these amino acids doing together to make a protein.

What is a Genome ?

Fancy name for all the genetic materials in an organism.

-By allowing scientists to know which genes link to inherited diseases , they can understand better this can help develop treatments.

How can Genomes be use in medicine ?

-Look at different genomes of different people to help they find the migration (movement) of certain populations around the world over history.

What does asexual reproduction produce ?

Genetically identical cells.

What does sexual reproduction produce ?

Genetically different cells.

What does the mother and father produce in sexual reproduction ?

Gametes these are produced by meiosis. Gametes contain half the number of chromosomes of a normal egg.

What is the process of sexual reproduction ?

sperm ( half set of chromosomes )+ egg ( half set of chromosomes ) = offspring ( full set of chromosomes , genes are mixture of mother and father )

What does asexual reproduction happen by ?

Mitosis.

What is the process of asexual reproduction ?

Parent cell ( full set of chromosomes ) = 2 new cells both contains the same genes of parent ( full set of chromosomes ). These are clones of the parent.

What is step one in the process of Meiosis ?

The parent cell has chromosomes in pairs. Half of the chromosomes have come from father and half come from mother.

What is step two in the process of Meiosis ?

The DNA in the parent cell is copied. It makes X- shaped chromosomes.

What is step three in the process of Meiosis ?

The cell divides and each new cell gets half of the chromosomes.

What is step four in the process of Meiosis ?

Each cell divides again. The X- shaped chromosomes are pulled apart. You end up with four daughter cells. These are the gametes.

What is in each gamete at the end of Meiosis ?

Only has one single set of chromosomes and is genetically different ( each has a different mix of the mother's and father's chromosomes).

How many pairs of chromosomes are there in every human body ?

23 pairs.

How many of these pairs control your characteristics ?

22 matched pairs

To determine the sex of an offspring what chromosomes are present in a male ?

X and a Y

To determine the sex of an offspring what chromosomes are present in a female ?

X and X

What are Punnett squares ?

A genetic diagram to determine the probability of something.

If its a dominant alleles what type of letter do you put in a Punnett squares ?

Capital letter

If its a recessive alleles what type of letter do you put in a Punnett squares ?

Small letter

Advantages of Embryo screening ?

Help stop people suffering. Treating disorders cots a lot of money. No laws to stop it going to far.