Quiz 3: Ocience - Lessons 8-11

Flashcards for reviewing Unicellular/Multicellular Organisms, leaf structure, and tissue types.

Unicellular Organisms

Organisms made up of one cell that carries out all the needed functions with the help of specialized organelles.

Multicellular Organisms

Organisms made up of multiple cells where each cell can be specialized to carry out specific functions.

Epidermis

A single layer of cells that protects the leaf on top and bottom without chloroplasts, allowing sunlight through and responsible for gas exchange, and has a waxy coating (cuticle) to protect the plant from diseases and evaporation.

Mesophyll/Ground

Tissue with lots of chloroplasts where photosynthesis occurs. Made up of Palisade (long/narrow, closely packed) and Spongy (round/loosely packed) cells.

Palisades

Long and narrow cells; closely packed under the upper epidermis in the mesophyll.

Spongy

Round and loosely packed cells below the palisades in the mesophyll, allowing for efficient gas exchange.

Vascular

Tissue that runs from the roots to the rest of the plant, including leaves.

Xylem

Transports water and minerals; located at the top of the bundle in a cross section.

Phloem

Transports sugar; located at the bottom of the bundle in a cross section.

Stomata

Small openings in the epidermal layer of the leaf that allow for the exchange of gas and water vapor.

Guard Cells

Cells that surround the stomata and control the opening and closing of the stomata based on the availability of water.

What are the 3 main tissue types in a leaf

Epidermis, vascular, mesophyll

What is the leaf

An organ to a plant

Which tissue has no photosynthesis

Epidermis

What organ has palisades and spongy

Mesophyll

What are the 2 process for entertainment conversion

Photosynthesis and cellular respiration

Photosynthesis

The process by which the chloroplast in plant cells convert solar energy into chemical energy in the form of glucose

What happened during the day

Photosynthesis

What is the formula for photosynthesis

6H20 plus energy plus 6CO2 into C6H12O6 plus 6O2

Explain the photosynthesis formula

Water enters via xylem then energy then carbon enters stoma and then sugar leaves via stem

What do plants do more photosynthesis it respite

Photosynthesis

Helpful in food chains as energy gets transferred

More photosynthesis

Formula for respite

Glucose + oxygen arrow carbon foodw use plus water plus energy

Explain gas exchange in leaf part 1

Carbon and oxygen exchanged through the stomata of the lead

Gas exhange part 2 in leaf

It enters and exits the leaf based off the conversation gradient and whether the plant is photosynthesis or respiring

Gas exhange in leaf - CO2 enters

Photosynthesis gas exhange

Oxygen enters in leaf gas exchange

Cellular respiration gas exchange

Explain gas exhcange in roots and stens

Roots and stems do NOT have chlorophyll and therefore do not undergo photosynthesis. They only carry out cellular respiration. They have special pores/raised bumps called lenticels for gas exchange

what are lenticles

 special pores/raised bumps for gas exchange

Xylem

• Transports water and minerals from Root to leaf

• Made up of long, dead, hollow cells (like a straw) linked from end to end.

• Without the xylem, the plant would die from water loss from transpiration through the leaf.

Pholem

tissue to transport sugar

what direction does the phloem go

Bidirectional transport of sugars In the summer, the sugars made in the Leaf move through the plant to the roots

What happens in the winter for pholem

In the winter, the stored sugars in the Roots move to the leaves

What is the phlem made of

Made up of living cylindrical tubes (with sieves between the tubes) linked from end to end

what is the pholem surrounded by

Surrounded by companion cells (living) that contain lots of mitochondria so that it can release energy required for the active transport of sugars from the leaves.

the push of water transport

Minerals in the soil are actively transported into the roots and water follows to dilute this concentration and enters through osmosis When this occurs, pressure builds in the roots creating a “push”. The water makes its way to the xylem where it is slightly pushed up.

what is the process of the push of the water transport

osmoisis

water transport of the pull

When the sun shines onto a plant’s leaf, the leaf will transpire and lose water. This creates the “pull” to bring the water up from the roots through the xylem.

The sugar transport first step

The organelle chloroplast makes glucose through the process of photosynthesis. The plant converts glucose into sucrose as it is less reactive and contains more energy per molecule. This allows for a more efficient transport and storage of the sugars.

what do the companion cells do in sugar transport

The companion cells use energy produced in the mitochondria to actively transport sucrose into the phloem.

what enviomrent do companions cells create during sugar trasnport

This creates a hyper tonic environment in the phloem which water from the xylem to enter through osmosis.

sugar trasnport part 3

The increase in pressure from the influx of water helps move the sap around to areas that require it.

Tropism

Plants respond to changes in their environment. Tropism is a plant’s biological response where it turns in a particular direction based on an external stimulus.

Phototropism

plants response to light

positive tropism

plant grows toward the lights

if plant grows towards the light

Maximizes exposure to light to increase rate of Photosynthesis

This typically affects the stem of a plant

negative phototropism

grows away from light - seen in the roots of the plants

gravitropism/geotropism

plants’ response to gravity

positive gravitropism

grows with the direction of gravity

negative gravitroposim

grows the opposite direction of gravity

negative gravitropism equals

positive phototropism

positive gravitropism equals

negative phototropism

Darwin and Darwin

determined which part of the plant detects the phototropic response

Boysen-Jensen

Determined it was a chemical signal produced in the tip that is responsible for the phototropic response.

Went

determined that auxin is a plant growth hormone that caused cells to elongate allowing it to bend towards the light. In the absence of light, a stem could still bend if auxin was introduced to the plant.