module 5: systems of life Flashcards
what are the 4 features of exchange surfaces
- large SA:V ratio
- thin barrier
- concentration gradients
- selectively permeable
how do you maximise gas exchange
-large SA:V ratio
-maximise the particle pressure
what is the equation for partial pressure
P(total)=Pressure(a)+pressure(b)+pressure(c)…..
what enviroment is harder for gas exchange
water because it is more denser and harder to move around in, therefore it is harder for gas exchange
how do plants undergo gas exchange
through photosynthesis and cellular respiration
how do insects undergo gas exchange
-they have gates that can be closes
- when they are open they allow for gas exchange
- when they are closed they prevent gas exchange
how do crustaceans undergo gas exchange
crabs have internal gills
-this is an open system
how do fish undergo gas exchange
-have internal gills
- this is a closed system
- they are controlled by the opening and closing of their mouth
is blue blood oxygenated
no
is red blood oxygenated
yes
what do alveoli do
they fill up with air
what causes the alveoli not to collapse
due to the lightless of the lung tissue
what happens to CO2 and O2 in the alveoli
- O2 is diffused out into the capillaries
- co2 is diffuses into the aveolius
why is BPG bad
it binds to hemoglobin instead of oxygen, changes the shape of haemoglobin
what are the factors that can influence hemoglobin dissociation
- high co2
increased acidity - bpg
what is the haldane effect
- CO2 binds to haemoglobin
-haemoglobin not carries o2 has a higher affinity for CO2 - the haldane effect facilitates the removal for CO2 at tissues with low partial pressure of o2
what molecule do muscles to have to store oxygen
myoglobin
what is myoglobin
- a protein that increases oxygens affinity
- binds to oxygen at low partial pressure
- used when we exercise
how are marine animals able to hold their air for so long
increased myoglobin and haemaglobin
- reduce their heart rate
reduce blood flow to their organs
how does COVID 19 affect the lungs
- Virus enters lungs
- Virus binds to alveolar wall cells and injects its RNA
- Infected cell produce many copies of the virus
-Alveolar cell destroyed virus particles released and infect neighbouring cells
what does the modella do
- it is apart if the brian that detects changes in the partial pressure of O2 and CO2 and pH in the cellubrial fluid
what is a chemoreceptors
chemical receptor that is sent to the breathing control center (modulla)
where are these chemoreceptos found in the lungs
-aorta
-modulla
-carotic bodies
what is the importance for sexual reproduction
produced offspring that are genetically different to their parents and increases the populaton of a species
why is reproduction expensive
- competition for mates and males
production of gametes
production of pheromones
what protein establishes maleness
-SRY protein
the absence of SRY
is female
what are the 3 major sex hormones that are produced by the gonads
-Oestrogen
-Androgens
-Progesterone
what secondary sex characteristics of testosterone
deeper voice
adams apple
public hair
increases sex drive
muscle growth
what are the secondary sex characteristics for oestrogen
-breast development
public hair increases sex drive
what is Oogenesis
Oogenesis is the process by which female germ cells develop into mature eggs
what are the steps of Oogenesis
Proliferation
Primary oocyte formation:
Growth and maturation of the primary follicle:
Secondary oocyte formation:
Completion of meiosis II
what happens at Proliferation
Oogonia undergo mitosis to increase in number during fetal development.
what happens at Primary oocyte formation:
Some oogonia differentiate into primary oocytes, which become surrounded by follicular cells to form primordial follicles.
what happens at Growth and maturation of the primary follicle
The primary oocyte and follicular cells grow, and the follicle becomes a primary follicle. The primary oocyte undergoes DNA replication but remains arrested in meiosis I.
what happens at Secondary oocyte formation
At puberty, some primary follicles mature, and the primary oocyte completes meiosis I, producing a secondary oocyte and a polar body
what happens at Completion of meiosis II
If the secondary oocyte is fertilized by a sperm cell, it completes meiosis II, producing a mature ovum and another polar body. The ovum and sperm fuse to form a zygote
