Biology NCEA Level 1

Aleurone (2)

- Protein stored as granules

- Releases amylase to convert starch into glucose

Endosperm (2)

- Food Stores rich in starch

- Supplies the seedling with glucose sugar as it grows

Cotyledon (2)

- Food Stores rich in starch

- Supplies the seedling with glucose sugar as it grows

Monocotyledon

- Only has one cotyledon and a separate endosperm

Dicotyledon

- Has two cotyledons with endosperms incorporated

Seed Coat/Testa (2)

- Provides protection for the enclosed embryo

- Can be dry and hard

Kernel Stalk/Hilium

Scar which is left on seed coat after seed has separated from its stalk

Radicle (2)

- First root

- Develops into main root

Plumule (2)

- First shoot (first bud)

- Grows into the main shoot and the first leaves

Micropyle

- Water is absorbed through here at the start of germination

Vernalisation

- The induction of a plant's flowering process by exposure to the prolonged cold of winter, (or by an artificial equivalent)

Scarification

Weakening, opening or otherwise altering the coat of a seed so that it can germinate.

Germination

The process in which a seed starts to develop into a seedling

Why is water important for germination? (4)

- Helps to soften the tissues of the seed

- Breaks dormancy/triggers germination

- Rehydrates the seed

- Stimulate the release of (activates) enzymes, which are needed for the creation of glucose (the other main ingredient for respiration).

Why is oxygen important for germination? (4)

- Respiration for the plant

- Energy for the plant

- Required for the process of respiration that must occur within the cells in order for energy (ATP) to be provided so that cell division/ growth to happen.

- Building molecules for other cellular processes

Why is warmth important for germination? (3)

- Changes in temperature trigger germination to start

- Provides the optimum conditions for cellular respiration to occur effectively (and therefore provide the much needed energy for growth.)

- Increases the metabolic rate at which the enzymes work efficiently

What is the stimulus to light called

Phototropism

What is the stimulus to gravity called

Geotropism

Positive tropisms

The plant grows towards the stimulus

Negative tropisms

The plant grows away from the stimulus

Primary Growth

The growth of the stem and the root; it increases in height

Secondary Growth

This occurs when the plant has stopped growing in length, and now grows in thickness

Photosynthesis

A process that takes place inside the leaf to produce glucose which is used as energy (ATP) for the plant

The Petiole

Attachment point to stem and is important for support

The Main (Mid) Rib

Holds the lead in the best position for photosynthesis

Lateral Veins

Carries water to all parts of the leaf

Cell Membrane

• Controls what goes in and out of the cell

Nucleus

• Contains the genetic material/DNA

Cell Wall (3)

• Surrounds the cell and gives support

• The cell wall surrounds the cell membrane and is made of cellulose (carbohydrate - a complex sugar).

• It is strong and gives the cell its firm shape.

Chloroplasts (3)

• Contains chlorophyll and absorbs sunlight

• Chloroplasts are the organelles involved in photosynthesis, they trap light and convert it to chemical energy.

• Chloroplasts are near the surface of the cell to increase light absorption and CO2 transfer.

Vacuole (2)

• Contains cell sap and gives support

• The vacuole contains cell sap - a solution of water, mineral salts and other substances.

Cytoplasm (2)

• Where all the chemical reactions happen

• The cytoplasm is where most of the cell processes take place

Waxy Cuticle (3)

• Outermost layer on the upper surface - It reduces water loss

• clear so that it allows light to pass through, and waterproof so that it prevents the loss of water by evaporation so that photosynthesis can take place.

• Reduces the amount of water lost through the stomata.

Epidermis (2)

• Upper layer of the leaf. It is almost transparent and its function is to protect the inner tissues

• The epidermal layer provides a thin layer of cells, which are transparent to allow the red and blue wavelengths of light through, and provide protection to the cells below.

Palisade Cell (7)

• Tightly packed cells, which are the main site of photosynthesis. They have lots of chlorophyll and have a regular shape

• The palisade mesophyll layer is found at the top of the leaf because these cells are specialised for absorbing the most sunlight.

• They can do this because they are long, with more chloroplasts than other cells found in the leaf.

• They absorb most of the light that first filters through the leaf because their cells are arranged longitudinally to allow more chloroplasts to be exposed to the light passing through the leaf.

• Found just below the upper epidermis (because this is where the most light is available).

• They contain large numbers of chloroplasts for photosynthesis

• Veins are very close by so that they can transport the raw materials and products of photosynthesis

Spongy Mesophyll (7)

- Loosely packed cells

- Facilitate the movement of gases and water vapour.

- Only a few chloroplasts

- The spongy mesophyll layer is found in the middle of the leaf.

- These cells have intracellular shapes producing air spaces in the leaf, which allows the carbon dioxide to diffuse through to get to the palisade cells, AND oxygen to diffuse out of the leaf.

- The irregular shape reflects any remaining light back through the leaf to be used by palisade cells.

- Spongy mesophyll is close to the palisade cells - short diffusion pathway thus easy gas exchange of both CO2 and O2

Vascular Tissue

• Made up of the xylem and the phloem. Carries water and food.

Stomata (9)

• Holes (pore like openings) that are found mostly on the lower surface of the leaf that allow gases to diffuse in and out of the leaf.

• Primarily the lower epidermis. (This means less water loss)

• Stomata allow CO2 into the leaf to use for photosynthesis and O2 out

• They also regulate the amount of water lost by leaves. This is done by the guard cells.

• The stomata open due to increased volume of water in the guard cells.

• The guard cells are cylindrical and are uneven in their cell wall thickness (the inside wall is thicker).

• Thus when the guard cells take in water and swell they bulge more to the outside (therefore opening up the stoma).

• When the guard cells lose water, they sag towards each other and thus the stoma closes.

• Triggers for the opening and closing of the stoma include carbon dioxide levels and potassium ion levels and circadian rhythms.

Guard Cells (4)

• Sausage shaped cells that control the opening and closing of the stomata and thus control the amount of gas /water vapour entering and leaving the leaf.

• Guard cells open and close to balance the amount of CO2 uptake and water loss by transpiration.

• Low water - closes

• Low CO2 - opens

Peduncle

The stalk of a flower

Receptacle

The part of a flower stalk where the parts of the flower are attached

Sepal

The outer parts of the flower that enclose a developing bud

Petal

The parts of a flower that are often brightly coloured

Stamen

The parts of a flower, usually with a slender filament supporting the anther

Anther

The part of the stamen where pollen is produced

Pistil

The ovule producing part of a flower

Stigma

The part of the pistil where pollen germinates

Ovary

The enlarged basal portion of the pistil where ovules are produced

Nectar

Produces sugary nectar which attracts insects

Bulbs

Swellings of leaves or stems at the base of the plant that, when removed, grow into a new plant

Tubers

Swollen roots or underground stems

Rhizomes

Underground stems that travel horizontal throughout the soil

Runners or Stolons

A long lateral (sideways) shoot that grows over the surface of the ground producing a new plant at the tip. Similar to rhizomes except the lateral stem travels above the ground.

Flower (2)

o Contains the male and female reproductive parts

o Once pollinated the female part (ovule) will make the seed

Leaves (6)

o Carbon dioxide is taken in form the air through tiny holes in the leaves

o Make food using

• Light energy from the Sun,

• Carbon Dioxide from the air,

• Water from the soil,

• To make sugars (carbohydrates) in a process called photosynthesis

Stem (2)

o Carries water and dissolved minerals up to the leaves and carries sugars down to the roots

o Supports the leaves and flowers

Roots (2)

o Water and minerals are taken up by the plant through the roots

o Roots anchor the plant in the soil

Coleoptile

The First Leaves

Asexual Reproduction

Produces genetically identical offspring

Sexual Reproduction

Needs to parents to create an offspring

Pollination

The process to bring the male and female gamete together

Fertilisation

The fusing of the gametes to form a zygote

Advantages of Asexual Reproduction (6)

- Non-reliant on partner, can reproduce on its own

- Energy Efficient

- Passes on Strengths

- More guaranteed success, not chance

- Reproduce any time

- Faster as not reliant on outside influences

- Can mass produce

Advantages of Sexual Reproduction (3)

- Produces genetical variation in the species so can adapt to changes in the environment

- Not all offspring will susceptible to the same diseases, and a disease can fought off through evolving the offspring to be immune to the disease

- Easy to spread due to seed dispersal

Seed Dispersal (5)

- Wind

- Insect

- Water

- Explosion

- Goal is to get far from the parent plant to reduce competition

Live Mass

Mass of living tissue, including water in the seed and the seedling

Dry Mass

Mass of the seed and the seedling without water