Biology Flashcards
what are gametes
sex cells
give an example of gametes in plants and animals
Human: egg cell and sperm cell
Plant: pollen grain and ovum
gametes have a _______ neucleus
gametes contain ____% of the needed genetic information
a) haploid
b) 50%
cells undergo a cell division called _______ to produce haploid gametes
Meaosis
what are the two main hormones that stimulates sexual development in females and males
Male: testosterone
Female: oestrogen
describe the route a sperm cell takes
-The sperm cell goes from the testes
-Up the sperm duct
-Into the prostate gland
- This is where it’s given nutrients and enzymes to live in the vagina (this is where it turns to semen)
-And exited the penis via the urethra
describe the route a sperm cell takes
-The sperm cell goes from the testes
-Up the sperm duct
-Into the prostate gland
- This is where it’s given nutrients and enzymes to live in the vagina (this is where it turns to semen)
-And exited the penis via the urethra
Gives 4 adaptations to the sperm cell and how there spezialised
Acrosome - has enzymes to break down teh cell membrane of the egg cell and some of the jelly
Midpeide - has lots of mitochondria and ATP so the cell has lots of energy
Neucleus - haploid so stores half the amount of chromosomes
Flagelum - streamlined tail to speed up movement
Gives 4 adaptations to the sperm cell and how there spezialised
Acrosome - has enzymes to break down teh cell membrane of the egg cell and some of the jelly
Midpeide - has lots of mitochondria and ATP so the cell has lots of energy
Neucleus - haploid so stores half the amount of chromosomes
Flagelum - streamlined tail to speed up movement
Give 3 adaptation of an egg cell
-Membrane to control what goes in and out f the cell
-Protective jelly
-Haploid neucleus
A ball of cells in which the egg cell matures
Follicle
The shredding of egg from ovary (and what day of cycle does this occur)
What hormone is active at this point?
Ovulation - day 14
LH (it promotes pogesterone production)
Bleeding that occurs when the lining of uterus is shed. Concequence of falling levels of __________
a)Menstruation
Pb)rogesterone
Hormone thats released from the brain (pertuitary gland), that promotes egg ________ in the follicle. It also promotes the release of ___________
(what days does this occur)
FSH
b) maturation
c) oestrogen
roughly days 6-13
Hormone responsible for the maintanence of the uterus lining, and forms the c_____ lu_______
at what point is this happening
Progesterone
corpus luteum
15-28
which nutrients does the mother deliver to the baby through the placenta
amino acids, glucose and oxygen
What waste products does the placenta remove from the babys blood
CO2 and urea
The placenta acts as a barrier that protects the baby by filtering out what substances
harmful chemicals and pathogens (like alcohol, drugs and viruses) however they can still pass through
The placenta acts as a barrier that protects the baby by filtering out what substances
harmful chemicals and pathogens (like alcohol, drugs and viruses) however they can still pass through
What does the placenta attach to, and where in the mothers body
the umbilical cord
the inner wall of the uterus
Where is the mother’s maternal blood deposited, and how are the substances exchanged between the two
Intervilius space
diffusion across the placenta
Where is the mother’s maternal blood deposited, and how are the substances exchanged between the two
Intervilius space
diffusion across the placenta
how are the vili in the placenta adapted for diffusion, and what do they diffuse?
large surface area
one cell thick
to allow diffusio of gases, nutrients and waste
oxygentated blood travels to the foetus via the ___________
umbilical vein
Deoxygenated blood travels back to the placenta from the foatus via the ____________
umbilical artery
How does the placenta help protect the baby from infections after birth
transfers antibodies from mother’s immuune system
3 stages of birth
diallation of cervix
deliverung of baby
delivery of afterbirth
(see book for more details)
What are the 8 life processes, and give a brief desription for all of them
MRS GRENC
a) Why is nutrition needed?
b) How do plants make their own food, and what is this called (show this in a word equation)
c) How do humans process food, and what is this called
a) Organisms must obtain food to provide energy to carry out the processes needed to stay alive
b) Plants use CO2 and water to produce O2 and glucose
—>called photosynthesis
—>this is called being autotrophic
c) Animals consumer other living organisms to obtain the energy they require
—>they break down lerger, more complex molecules into simpler ones through digestion
—>this is called being hetrotrophic
What is the equation for aerobic respiration
aerobic
respiration
glucose+oxygen —> carbon dioxide+water
the energy is transferred through ATP
Desribe excretion in humans, and give some examples of waste products
-chemical reactions that take place in living cells are described as metabolic
—>these produce waste products some of which can be toxic and need to be removed
-this is the process of excretion
—>co2 from respiration
—>water from respiration and other chemical reactions
—>urea which contiains nitrogen from the breakdown of proteins
Describe excretion in plants, and how it differs from night to day
Oxygen from photosynthesis
CO2 from respiration
Water from repiration and other chemical reactions
Night: CO2 excreted due to rate of respiration exceeds rate of photosynthesis
Day:oxygen is excreted due to rate of photosynthesis exceeding rate of respiration
Water vapour is always excreeted through transpiration
What is homeostasis?
The control/regulation of internal conditions in a cell/organsism within a narrow range
What is excretion?
The removal of toxic waste products in living organsisms that are produced via matebolism
Name 3-5 things homeostasis controls in the body
-CO2 levels in blood
-core temoerature
-water concentration in blood
-glucose concentration in blood
-pH of cells
Draw a labelled diagram of the nephron, and the processes that happen in it
go to mind map or book
What is ultrafiltration?
the process by which larger molecules are separated from the smaller ones by high pressure to push the smaller ones into the bowman’s capsule
What is osmoregulation
keeping water and salt content of the internal environment constant
What are the contents of urine?
-water
-urea (toxic, nitrogenous waste product formed when excess amino acids are broken down in the liver into carbohydrates ((these can be stored unlike amino acids))
-salts
What is negative feedback?
Negative feedback is the action taken by the body to return something to a normal / optimum level following a deviation from that level.
—>It is how the body keeps conditions within it constant at the optimum level
Explain how the body reacts to water concentration increasing in the blood
-the change in blood concentration is detected by hypothalamus (in the brain)
—>in this case if the water potential has increased (more water then there should be)
-the pirtuitary gland releases more ADH
—>this makes the collecting duct of nephron in kidneys less permeable to water (so more water can get into the urine)
-concentration of blood returns to normal
-negative feedback loop switches off and ADH production is no longer inhibited
What is the difference between nervous and endocrine system?
-the nervous system uses electrical impulses to send messages through neurons
-endocrine glands use hormones to send messages to the target cells through the bloodstream
Name 5 things that happen when the body gets too hot?
(why might getting too hot be a problem)
too hot for the enzymes so they denature
- Vascoconstriction
-dialate arteriale (widen) so capillaries close to the skin which allows heat to be lost - Sweating
-when sweat is evapourated, energy goes with it - Muscles (hair)
-Hair erectus muscles relax/go down to stop the layer of insulation
-The relaxtion also stops heat from being produced
-Released stored heat in hair - Metabolic rate
-slow down metabolism, so not as much heat is generated
What is the core body temp. and how much can it chnage either way
37 degrees
2 degrees either way so ezymes are at their optimum temp.
What are the following:
a) stimulus
b) receptor
c) coordinator
d) effector
e) responce
a) a change in environment
b) the part of an organism tat detects a simulus by transduction (changing it’s energy into electrical energy for nerve impulses)
c) central nervous system - spinal cord or brain
d) contracting muscles or hormones secreting gland that carries out response
e) a reaction to the chnage in environment
4 factors affecting rate of diffusion
- The concentration gradient
- The surface area to volume ratio
- The diffusioin distance
- The temperature
