Year 11 Apres Mock Paper 1 Content

Combination of Mentrual Cycle, Repodrocution in Humans and Plants and Preganancy

the menstrual cycle is a

series of changes that occur in a women’s body around every 28 days

the changes in a women’s body is controlled by

sex hormones

menstruation is commonly known as

a period

ovulation is the

release of an egg

the released egg during ovulation travels

down the oviduct to the uterus

why does menstration occur?

fertilisation of an egg doesn’t occur

menstruation/a period is the

breakdown of the thickened uterus lining

ovulation occurs on day

14

menstruation lasts

5-7 days and signals the beginning of the next cycle

after menstruation what happens to the lining of the uterus?

begins to thicken again in prep for a possible implantation in the next cycle

before day 14 (ovulation) which hormone peaks?

oestrogen

oestrogen does what?

causes the uterus to build up and thicken

progesterone does what?

causes the uterus lining to thicken further

progesterone is high after

ovulation

when progesterone levels decrease,

the uterus lining breaks down, causing menstruation to occur

2. once the ova (egg) develops in the follicle, it produces what?

oestrogen

5. once ovulation occurs, the follicle becomes

corpus luteum and starts producing progesterone

corpus luteum is the

remains of the follicle in the ovary

the corpus luteum role is to

produce hormones for a potential pregnancy

6. progesterone maintains the uterus lining, however if the ova is not fertilised…

the corpus luteum and uterus lining break down and progesterone levels decrease

6. OR if egg is fertilised and pregnancy has occurred

the corpus luteum continues producing progesterone to prevent the uterus lining from breaking down and aborting the pregnancy

what does a foetus need from its mother’s blood?

amino acids, glucose, fatty acids, mineral ions, vitamins, water and oxygen

in the placenta, the mothers blood comes in very close proximity with the foetus, but never what?

mixes her blood with it

foetus’ blood connects to the placenta via the

umbilical cord

the mothers blood absorbs

wast p

a zygote is a

fertilised egg

an embryo is

initial stages of development of a multicellular organism

a foetus is an

unborn human

secondary sexual characteristics occur during

puberty

secondary sexual characteristics are controlled by

oestrogen and testosterone

female secondary sexual characteristics include:

breasts develop, body hair, menstrual cycle begins, hips widen

male secondary sexual characteristics include:

growth in p and testes, facial and body hair, voice breaks, testes begin to produce sperm

flowers are the

reproductive organs of plants

male parts of the flower

stamen = anther and filament

female parts of the flower

carpel = stigma, style and ovary

plants produce

pollen

pollen contains

a nucleus - which is the male gamete

pollen is produced in the

anther

pollination is the

transfer of pollen grains from the anther to the stigma

2 types of pollination are called

wind and insect

insects are

pollinating agents

insects collect

nectar from flowers

when an insect enters the flower

it brushes against the anther, which deposits its sticky pollen onto

when an insect visits another flower,

it brushes against the stigma, depositing the pollen from the first flower, resulting in pollination

inside the ovary are the

ovules, containing the ova = female gamete

petals:

large and bright to attract insect

scent and nectar:

entice the insect to push parts of the stamen, to get to the sweetness

anther:

inside the flower and contains the pollen grains, stiff and firm to brush against insects

stigma:

inside the flower, where pollen grains stick to it when an insect brushes past

stamen:

enclosed within a flower so that insect must make contact with it

pollination in wind pollinated plants

the anther opens and sheds its pollen into open air. the pollen is blown by the wind and lands on the stigma

wind petals:

small and dull

wind scent and nectar:

absent

wind anthers:

swing loosely so that pollen grains fall easily

wind stigma:

outside the flower, large and feathery in order to catch pollen grains

wind stamen:

exposed so that wind can easily blow away pollen

cross vs self pollination:

pollen grains are transferred from a plants anther to another plants stigma vs pollen grains are transferred from the same flower’s

what do organisms use to respond to changes in their environment

communication systems - endocrine and hormonal

homeostasis is the

maintenance of a constant internal environment

examples of homeostasis?

the maintaining of body temperature and water content

what does a coordinated response require?

a receptor, stimuli and an effector

plants do what in order to grow

respond to stimuli

a tropism is a

directional response made by plants based on light and gravity

the response to light is called

phototropism

the response to gravity is called

geotropism

shoots grow

towards the light, away from gravity

roots grow

towards gravity, away from light

shoots are

positively phototropic and negatively geotropic

roots are

positively geotropic and negatively phototropic

auxin is a

plant growth hormone which controls the directional growth response of plants

where is auxin produced

at the tip of the shoots, which diffuses below the tips

in the shoots, auxin promotes

cell elongation in order to grow towards the light

in the roots, auxin inhibits

cell elongation in order to bend away from the light

the nervous system

works by nerves impulses, transmitted through nerve cells in a fast, short lived, response. it has a localised effect on the body.

the endocrine system…

works by hormones, transmitted through the blood stream in a slow, long lived, response. it has a widespread effect on the body.

CNS consists of

the brain and spinal cord and is linked to sense organs by nerves

stimulation of receptors in the sense organs causes

them to send electrical impulses along nerves in and out of the CNS, resulting in rapid responses.

synapses are

gaps between 2 neurons

role of neurotransmitters

they diffuse across the synapse, allowing for a new electrical signal in the next neuron

neurotransmitters are

chemical messengers that pass info from one neuron to the next

stages of the reflex arc

stimuli - receptors in sense organs detect stimulus - receptors send electrical impulses along sensory neurons to the CNS - which is where the relay neuron transfers the info to a motor neuron - to the effector to act accordingly

reflex arc: touching something hot

1. touching a hot object causes a stimulus

2. the receptors in your hand detected the stimulus and send electrical impulses via sensory organs to the CNS

3. the relay neuron then transfers the info to a motor neuron

4. the motor neuron travels to the effector (the muscle) which contracts and moves your hand away from the object

what is the function of the sclera

tough outer layer that protects the eye

what is the function of the cornea

transparent lens that refracts light as it enters the eye

what is the function of the pupil

hole that allows light in

what is the function of the iris

controls the diameter of the pupil, therefore controlling how much light enters the pupil

what is the function of the retina

a transparent disc that focuses light onto the retina (cones detect colour and rods detect light intensity)

what is the function of the optic nerve

contains sensory neurons which carry out nerve impulses to the brain

what is the function of the fovea

a region in the retina with the highest denisty of cones

the blind spot of an eye is

the point at which the optic nerves leaves the eye and there are no receptor cells

when the eye sees a near object…

ciliary muscles contract, suspensory muscles relax and the lens becomes more convex - rounder

when the eye sees a far away object…

ciliary muscles relax, suspensory ligaments contract and the lens become less convex - flatter

in the iris there are the

circular and radial muscles

when the eye sees in dim light…

circular muscles relax, radical muscles contract and pupil dilates so that more light enters the eye

when the eye sees in bright light…

circular muscles contract, radical muscles relax and pupil constricts so that less light enters the eye

if the body is too warm what does the skin do?

starts to sweat, so that when it evaporates from the skin surface, it has a cooling effect. this is because heat energy is needed to change from liquid to gas and that energy is then taken away from the body by vapour