Biology Paper 2

Homeostasis

The maintenance of a constant internal environment

Receptor cells

_________ _____ detect change in stimulus.

CNS

____ receives and processes information from receptor cells.

Effectors

________ carry out a response.

sensory neuron

Electrical impulses pass from receptor cells along the _______ ______ to the CNS.

Neurotransmitter released

What happens at a synapse?

Diffusion

How do neurotransmitters travel across a synapse?

motor neuron

Electrical impulses pass from CNS along the _______ ______ to the effector which performs a response.

Cerebral Cortex

Which part of the brain is responsible for language, memory and consciousness?

Hypothalamus

Which part of the brain is responsible for maintaining body conditions?

Cerebellum

Which part of the brain is responsible for balance and coordinating movement?

Medulla

Which part of the brain is responsible for heart rate and breathing rate?

Suspensory ligaments

A

Suspensory ligaments

Holds lens in place

Lens

B

Lens

Focuses light onto retina

Cornea

C

Cornea

Refracts light into eye

Pupil

D

Pupil

Controls how much light enters eye

Iris

E

Iris

Controls size of pupil

Sclera

F

Sclera

(Tough outer layer) Protects eye

Optic Nerve

G

Optic nerve

Carries signals to brain

Retina

H

Retina

Contains light-sensitive receptor cells (rods and cones)

Ciliary Muscle

I

Ciliary muscle

Changes shape of lens

Accomadation

Image focused onto back of retina

loosen / thickens

When object is nearby, suspensory ligaments ________, lens ________

thins

When object is distant, lens ________

dilation

Dim light causes pupil ________

constriction

Bright light causes pupil ________

circular muscles / radial muscles

In pupil dilation, ______ _______ relax and _______ _______ contract.

contract / relax

In pupil constriction, circular muscles ______ and radial muscles _______

Myopia

Short sighted

In front of retina

Myopia: light focused...

Concave lens

Myopia cure

Hyperopia

Long sighted

Behind retina

Hyperopia: Light focused...

Convex lens

Hyperopia cure

Thermoregulation / 37

________ is the maintenance of the body’s optimal internal temperature ___°C

endocrine / slower / longer lasting / blood

__________ system compared to nervous system:

* __________
* ________ _________
* happens via ________

Adrenal gland

Which gland releases adrenaline?

Pancreas

Where is insulin and glucagon released?

Thyroid gland

Which gland releases thyroxine?

glucose / pancreas / insulin / glucose / glycogen / liver / muscles

After eating, ___________ levels rise. To counteract this, ___________ releases ___________ which causes ___________ to be converted to ___________ which can be stored in the _______ or _________.

glucose / pancreas / glucogon / glycogen / liver / muscles / glucose

After exercising, ___________ levels fall. To counteract this, ___________ releases ___________ which causes ___________ in the _______ or _________ to be converted back to _________.

type one diabetes

______ ____ _________: No insulin produced

type two diabetes

______ ____ _________: Body cells no longer respond to insulin

osmoregulation

__________________ is the control of water levels and mineral ions in the blood

hypotonic / lysis

When red blood cells places in ___________ solutions, water enters the cell which causes _______.

hypertonic / crenation

When red blood cells places in ___________ solutions, water leaves the cell which causes __________.

nephrons / capillaries / urea / water / mineral

Kidneys contain ___________ which are tubules surrounded by ___________ which remove ______ as well as excess _______ and ________ ions

filtration / selective reabsorption / formation of urine

Stages in kidneys producing urine:

* ___________
* ___________ _____________
* ___________ ___ ________

protein / amino acid / ammonia / urea

Deamination: ___________ → ________ _____ → ___________ → ______

pancreas

Where does deamination occur?

semi permeable membrane / blood / concentration gradient

Kidney Dialysis

* ______ _________ __________ seperates the blood and dialysis fluid


* The dialysis fluid contains ________
* ____________ _________ causes ______ to diffuse from the blood into dialysis fluid

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lysis

What is the biological word for cells bursting?

crenation

What is the biological word for cells wrinkling?

14

Which day does ovulation occur?

pituitary gland / egg maturation / oestrogen production

FSH - Where is it produced? What does it stimulate? (2)

ovaries / uterus wall repair / stop of FSH production / release of LH

Oestrogen - Where is it produced? What does it stimulate? (2)

pituitary gland / ovulation / progesterone production

LH - Where is it produced? What does it stimulate? (2)

ovaries / uterus wall maintenance

Progesterone - Where is it produced? What does it stimulate?

auxin / plant growth / tissue culture / rooting powder / weeds

______

* Stimulates ______ _______
* Possible uses: growth medium for ______ _______ ; ______ _______ for cuttings to become new plants ; killing ______ by disrupting growth patterns

gibberellins / dormancy / germination / flowering / larger fruits

___________

* Control ___________
* Induces ____________ and _________. Also, grows _________ ________

ethene / ripening / cell division

_________

* Stimulates ________ of fruit
* Controls ______ ___________ during plant growth

response to stimuli

What is a tropism?

toward stimuli

What direction does a positive tropism act?

opposite stimuli

What direction does a negative tropism act?

gravity / root / minerals / nutrients / soil / stability / stem

Geotropism is growth in response to ___________. A positive geotropism has growth on the _____ tip, so it can receive ___________ and ___________ from the ____ and give the plant ___________. A negative geotropism has growth on the _____ tip.

light / stem / light / photosynthesis / root

Phototropism is growth in response to _________. A positive phototropism has growth on the ______ tip, so it can receive ______ for ______________. A negative phototropism has growth on the ______ tip so roots don’t dry up and water intake can be maximised.

shoot / shaded / elongation

Auxin response to a positive phototropism:

Auxin is produces in the tip of _______. Auxin moves to the ________ side of the plant, causes cell ______________ and the plant grows faster

root / gravity / elongation / roots

Auxin response to a positive geotropism:

Auxin is produces in the tip of _______. Auxin moves to the side of the plant towards ________, stops cell ______________ and the _______ grow downwards.

sexual / gametes / genetic

___________ reproduction is the fusion of ___________, which mixes ___________ information

asexual / mitosis / clones

___________ reproduction uses the process of ___________ to produce offspring that are _________

sexual / variation / natural selection / selective breeding

Advantages of ___________ reproduction:

* Produces __________ among offspring
* Survival advantage by ___________ ___________
* ___________ ___________

asexual / faster / disease / infavourable

Advantages and disadvantages of ___________ reproduction:

* ___________ than sexual reproduction
* ___________ could annihilate the population
* Species could die in ___________ conditions

human host / mosquito vector

Where do malaria parasites reproduce sexually? Where do malaria parasites reproduce asexually?

spores / variation

How do fungi reproduce asexually? Why do fungi reproduce sexually?

runners / seeds

How do strawberries reproduce asexually? How do strawberries reproduce sexually?

bud division / seeds

How do daffodils reproduce asexually? How do daffodils reproduce sexually?

cell → nucleus → chromosome → DNA → codon → gene

Place the following terms in order (from big to small): Nucleus, cell, chromosome, gene, DNA, codon *(formatting note: separate answer with arrow)*

nucleus

Where does transcription occur?

DNA unwinds / mRNA / copy / codons / mRNA / nucleus / cytoplasm / tRNA / ribosomes / amino acids / tRNA / protein

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* Transcription: Section of ______ ________ so _____ can make a _______ of the ________
* Translation: _____ moves from __________ to _________, this is ‘read’ by ____________. ________ use this info to bring the correct ____________ _______, in the correct order
* Enzymes link the amino acids, ______ disconnects, ________ molecule folds itself up

cytoplasm

Where does translation occur?

3 bases / amino acid

What is a codon? What does a codon code for?

Genotypes

___________ tell us which alleles are present

Phenotypes

___________ tell us which characteristics are caused by alleles

Homozygous

What are two copies of the same allele called?

Heterozygous

What are two different alleles called?

XX

Female chromosomes

XY

Male chromosomes

cell membrane disorder / recessive

What is cystic fibrosis? Is it dominant or recessive?

extra toes or fingers / dominant

What is Polydactyly? Is it dominant or recessive?

skin / hypothalamus

__(two answers)__ contain temperature-sensitive receptors.

selective / characteristics / bred / characteristics / repeated / generations

____________ breeding stages:


1. Individuals with desired ____________ selected
2. They are ________ together
3. Offspring with desired _____________ selected and bred
4. ____________ over several ____________