Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology me > B2.2 > Flashcards

B2.2 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Why is surface area to volume ratio important and why dant multicellular diffuse simply like unicellular do?

So what do multicellular do and have to overcome this

A

The bigger the SA: V ratio, the more diffusion can happen. Unicellular organisms have small diffusion distances and nutrients can diffuse quickly enough it o them QUICKLY ENOUGH FOR THEM TO SURVIVE, BECAUSE THEY HAVE HIGH HIGH SA:V

We can’t do diffusion like them as our sa:v too low, and diffusion distance too short (cells deep in the organism) and because as: v so low we can’t do it fast enough to sustain life….

So multicellular specialised cells and organisms, and transport…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are alveoli in lungs adapted to maximise rate of diffusion into the blood?

A
  • (ventilations move air in and out- maintains a steep concentration gradient of oxygen )
  • thin alveolus walls- short distance
  • large number of alveoli gives a surge surface area to volume ratio
  • good blood supply- always removes oxygenated blood and bringing in deoxygenated blood - maintains steep concentration gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do villi in small intestine maximise diffusion if food particles?

A

Villi have

  • a rich blood supply at all times, this produces a steep concentration gradient so a STEEP concentration gradient is maintained, and more efficient diffusion
  • large surface area to volume diffusion , which also increases rate of diffusion
  • the walls are only ONE CELL THICK, shorter distance for diffusion= more
  • even microvilli on the vili increase surface area even more….
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why are transport systems in multicellular needed?

A
  • only exchange surfaces are adapted , so a system is needed to transport exchanged molecules to where they need to go…
  • waste products need to be transported out too, like urea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Plant cell adaptations briefly for exchange?

Root hair and leaves, especially stomata

A

Ieaves

  • broad and thin: large surface area, but short distance gas has to go to
  • air spaces in leaf, allowing gas to move between cells easily but also increase surface area
  • ALSO STOMATA IN LOWER SURFACE OF LEAVES, ALLOW FOR GAS EXCHANGE

Root hair cells
- hair like , increase surface area for osmosis, and increase the amount of active transport that can happen at one time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is our circulatory system made out of? (Basically)

A

1) heart
2) blood
3) blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What makes our circulatory system a double circulatory system?

What makes our system a ‘closed system’

What is an advantage of a double circulatory compared to other animals like fish who din’t

A

For every circuit of the body, blood flows through the heart two times (one from heart to lung, then lung to heart and rest of body)

2) all the blood remain within the heart and vessels, making it closed.

The fact that the blood returns to the heart after getting oxygen means it can be lumped again but at extremely high pressures. This is useful because it increases rate of blood flow to organs, who need more oxygen for activities..

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Arteries

A

1) Carry blood away from the heart to organs under HIGH PRESSURE
2) Because the heart beats blood at high pressure, the artery walls are THICK AND MUSCULAR.
- The thick layer of elastic fibre and muscle expand with each force of contraction and snap back (like rubber band) called recoil and this helps push the blood further
3) has a small lumen (space in middle)
A smooth lining too between the Lumen and muscle, but this don’t mean anything

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Veins

A

Veins take blood back to heart in low pressures

1) therefore, the walls can be thin and the wall of muscle and elastic fibres can be thin too
2) has a large lumen and this means more blood flow can happen, (don’t need to be small because not high pressure)
3) has one way VALVES to stop the blood going back away from heart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Capillaries

A

Capillaries connect arteries and veins in tissues and organs

  • they Form a network so every cell is always close to a capillary , so that they can always exchange substances with things
    1) walls are SEMIPERMEABLE, too let certain substances in and out
    2) walls are very thin- ONE CELL THICK, decreasing distance for diffusion…
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Summary on circulatory system

A

1) double circulatory (blood twice per journey, good for more pressure)
2) artery blood away high pressure= thick walls to withstand, and thick elastic fibres and muscle to do recoil and push blood further. Small lumen for high pressure
2) veins blood to heart, low pressure so walls and elastic fibre muscle can be thin. Large lumen to help with blood flow. Also has one way valves ensuring blood goes to heart
3) capillaries one cell thick and connect between veins and arteries, this makes a network so all cells are close to a capillary to get and exchange substance with them. Distance for diffusion is small. Also semi permeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The heart is made of a cardiac muscle, the only type. What is different of this compared to others?

A

Cardiac muscles don’t receive nerve impulses from the brain, because they work all the time (70 beats per minute)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does blood go through the heart (detail 6 marks )

Why is the left side (ventricle area) more thick then right side.

What are the names of arteries giving heart its own supply of oxygenated blood?

A
  • Deoxygenated blood enters the right atrium of the heart through the veins cava (vein).
  • when the right atrium fills up, the blood is pumped to the right ventricle when the heart beat. A VALVE IS PRESENT HERE TO STOP BACKFLOW into the atrium again.
  • the heat beats again, and the blood in the right ventricle is pumped via the pulmonary artery to the lungs, where gas exchange takes place
  • the oxygenated blood enters the heart again vis the pulmonary vein into the left atrium.
  • when the left atrium fills up, the heart pumps the blood into the left ventricle, and again a valve is present here stopping backflow.
  • finally when the blood is full in the right ventricle, heart pumps blood via the aorta in high pressures around the body .

1) the left ventricle area has thicker muscular walls then the right side, because this is the side the has to pump the blood under such high pressures.
2) there are also valves into the arteries, which open and close accordingly.
3) heart has lot of mitochondria for respiration to bear, has own blood supply to get nutrients here and co2 from respiration out. These called coronary arteries…
4) remember left and right side swap.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is blood made up of (4 things)

What do white blood cells, red and platelets do?

A
  • plasma, red, white blood cells and platelets

1) white blood flew- cell they do have a NUCLEUS, and they fight disease by making antibodies, or by changing shape to engulf (eat and destroy the antibodies) them
2) red blood cells- carry oxygen around the body. They are small and flexible enough to fit into lumen of capillaries (which are small) one at W time. Remember biconcave, no nucleus, packed with haemoglobin…
2) platelets. These are tiny structures that help blood clot, to stop it from leaking out (haemophilia when platelets bruh)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do plasma do?

A

Pale yellow liquid which is blood - blood cells. IT ISNTHE WAY MANY MINERALS AND THINGS ARE TRANSPORTED BY THE BLOOD.

  • 90% of plasma is water
  • digested molecules like glucose and amino acids
  • carbon dioxide from cells to lungs
  • hormones and antibodies
  • UREA (breakdown of excess amino acids in liver)
  • excess water and water in general….
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a vascular bundle, advantages of this?

What does phloem transport and what is translocation

What does xylem transport ?

Where do all these systems get there things from/ transport to?

A

1) plants are made of of two transport systems- phloem and xylem. This combination is found close to each other in plants and forms a vascular bundle. It also provides support to the plant as well as being transport systems.
2) the phloem transport dissolved sugars made in photosynthesis to the meristems for growth but also to the roots as a storage (like potato)- translocation is this movement of sugar
3) xylem Transports water AND MINERAL IONS (from active transport) FROM THE ROOTS to the plant stem leaves and flowers.

17
Q

Structure of phloem (flow of sugars…)

Differences briefly to xylem

A

1) Phloem cells are made of living cells, rather then dead for xylem
2) Unlike the xylem, the end walls aren’t completely broken down, instead SIEVE PLATES are formed (tiny holes within cell wall to allow dissolved sugars through…)
2) (both xylem and phloem have no nucleus, but the phloem cells are alive, so a COMPANION cell is there for each cell carrying out the living functions for both of these cells.)

3 )Finally phloem Transports dissolved sugars both UP AND DOWN the stem, unlike the xylem which only transports water UP.

18
Q

Structure of xylem

A

1) Made up of dead cells
2) These have no end walls, which basically forms a tube (lumen ) allowing the water to go through
3) The remaining cell wall are thickened with cellulose,
Dividing structure (think tree bark)
4) ONLY GOES UP, not down…

19
Q

HOW DO vascular bundles provide support for plants (3 points )

A

1) they are form a network and found in LEAVES providing support to the softer leaf tissue
2) found on the OUTSIDE OF STEM, giving it strength allowing it to resist wind breeze and bending
3) found in CENTRE OF ROOT gives it strength an acts like an anchor so the plant stays put..

20
Q

What is transportation

What transpiration stream?

A

Transportation is the loss of water from a plants leaves. A constant flow of water from the roots, stems and leaves is called a transportation stream.

21
Q

Why does water leave the leaves?

How do guard cells control the opening and closing of stomata?

What are Guard cells sensitive to and what special about their cell walls that allow them to move

A

The Stomata of the leaves allow for carbon dioxide to diffuse in and oxygen to diffuse out. The control of them are done by guard cells- when there is a lot of water, the guard cells become turgid and open, allowing gas exchange to happen, but when they isn’t enough water available, guard cells remain close so some photosynthesis can take place.

  • Guard cells SENSITIVE TO LIGHT, so at night even with water they din’t open. Also cell walls are a THIN outside but thick inside , to allow for movement and flexibility
    %a
    2) When stomata is open, water will evaporate from the cells inside the leaf into the leaf air spaces. Now there is a high concentration of water vapour in the air spaces and a low concentration of water vapour in the air - so diffusion happens and water leaves the plant - this is transpiration.
22
Q

How does water transport through a plant?

A

1) diffuses by osmosis from soil to root hair cells. Water then travels cell be cell until it reaches the centre, where the xylem is. It can do then be transported up the xylem to where the plants need it.
When it is at leaves, with opening of stomata and diffusion and evaporation, water leaves the plant .

23
Q

What are the effects of transpiration? Advantages?

A

The loss of water creates a pressure difference like a straw. There is lower pressure at top, but higher pressure of water at bottom, so water moves through the tube.

Advantages of transportation are a constant flow of water keeps the plant cool and provides it with minerals. Along with supply of constant water for photosynthesis and also tutor pressure

24
Q

How is excessive plant water loss controlled?

A

Tjhe upper surface of leaves are coated in a waxy waterproof layer- called the CUTICLE. In hotter conditions like cacti this is more thick and shiny.

  • Finally most of the stomata is found UNDER THE LEAF, to reduce evaporation by being in direct contact of the sun. Plants of hotter climate have no stomata at the top at all…
25
Q

What will happen if the plant loses more water then it takes in.

A

The plant wilts because of a loss of tugor pressure and droops.

The stomata due to the guard cells close, reducing further water loss but also preventing PHOTOSYNTHESIS. If no more water given, it will die…

26
Q

So further explanation of structure in leaf (not noecessary but for understanding)

A

X- top of leaf are epidermal cuticle waxy waterproof. This reduces transpiration but also is transparent, letting light in for photosynthesis.

  • Next you see the Upper Palisade (mesophyll : middle) cells. These are responsible for most of the photosynthesis (remember specialised, most chloroplasts, regular shape to pack most in, etc…)
  • Next you have lower spongey mesophyll cells. These aren’t regular shape but do have gaps between them- air spaces. This improves the surface area available and increase diffusion of gasses.
  • Finally is the guard cells and the stomata, where water leaves and gas exchange happens…
27
Q

What factors effect rate of transpiration?

3 increase, 1 decrease

remember the graph (plateau ) for light intensity- why?

A
  • Temperature (more heat, more evaporation and water loss)
  • Increase light intensity (stimulates more photosynthesis, meaning stomata will open more causing water to leave). HOWEVER THIS PLATEUS BECAUSE ONCE ALL THE STOMATA ARE OPENED, THE RATE CANT BE INCREASED ANY MORE…
  • Air movement ( normally water vapour stays in surroundings, causing concentration gradient to remain low but in windy conditions it becomes higher.
  • (surface area , more stomata, more water let out)

-HOWEVER humid conditions do the opposite, lowers the concentration gradient as there is more water vapour in the air, leading to lower transpiration… decrease= increase, humidity graph higher to low

28
Q

How to investigate factors involving transpiration?

A

USE A POTOMETER
- The photometer actually measure the water uptake by a plant, but the water uptakes by plant is proportional to the water loss by a plant…
1) set up a potometer: 1) Cut a plant submerged in water (to ensure no air goes in) at a Tilt for more SA of water absorption.
2) Take an air bubble into the potometer by lifting and putting back the end of the capillary tube quickly.
3( record the start distance of the air bubble and close the reservoir tap.
4) as transpiration happens more water is taken up by the plant, and the air bubble moves.
5) you can calculate speed of the air bubble (distance/time) and use that as an estimate.

Reservoir there just to reset and keep doing the practicals. Remember to control time, other conditions when isolating one etc.

29
Q

How can you change conditions to investigate transpiration?

A

Temp- use two different room sof different emus
Light intensity c use a lmao and different distances + inverse square law
Wind movement= use a fan vs not a fan…

Surface area, take leaves off, and you should see drop of transpiration.

Biology me (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions